Roosdiarto Rooskandar, ST., YG1CRR Weblog

About Me & How To Contact Me

2011-09-20T23:15:00.000+01:00

My name is Roosdiarto Rooskandar. My nickname is Arrie. I live here in Bandung City, Indonesia, about 110km South East Jakarta (capital). My residence altitude is about 875m above sea level, so temperature here is running cool, from 15-20° Celcius along the year. From 1985-1994, I studied in Bandung Institute of Technology (ITB). My study was Industrial Engineering focused on Industrial Management. My studies from Junior High School up to 1994 were fully subsidized by President Mr. Soeharto government, as rest of youths studied in governmental schools. From 1997-2005, I studied in private university named ST-INTEN Bandung. My study was Wireless Telecommunication Engineering. From this university, I have my degree on Wireless Telecommunication Engineering. At 2010, my age would be 44, and still single. My hobbies are electronic and wireless telecommunication researches, amateur radio, sports, musics, and sight seeing.

My favourite singers, and bands include Coco Lee, Laura Pausini, Luis Miguel, Mezzoforte, Incognito, Casiopea, and many others. Between national musicians, I like Ruth Sahanaya, Chandra Darusman, and many others. My musical flow tends to Fusion (between Jazz and Rock).

My researches include designing VHF FM transmitter, designing HF AM transmitter, designing effective antennas, propagation, atmosphere ionization, effect of Sun to radio propagation and weather, etc.. My callsign in Amateur Radio is YG1CRR. I DX (communicate internationally) on 7 MHz CW & Phone, 21 MHz CW, and 28 MHz CW. I've joined ORARI (Indonesian Amateur Radio Organization) since 1990.

Since very beginning, my interest is on research of Telecommunication, and in future, I hope to establish my own industry, design and produce Amateur Radio equipments. And with my products, I hope I could relate everyone in Earth and Universe easily, cheaply, conduct friendship and peace between Nations, and communicate science and technology Worldwide to boost World's economy. May God realizes.

If you like to contact me or have questions, use:
Bukit Dago Utara II/3, Bandung, Indonesia 40135 (home)
To see my home from satellite: Latitude: 6.86825°S Longitude: 107.61776°E: http://maps.google.com/maps?q=-6.86825,107.61776
Ph: +62-22-2503241
Mobile: +62-852-20056566(SMS)
Webs: http://arriesite.blogspot.com/ , http://facebook.com/arrieweb , http://www.qrz.com/db/yg1crr
E-mail: arrieweb@gmail.com
ORARI National QSL Bureau: PO Box 1096, Jakarta, Indonesia 10010
West Java QSL Bureau: PO Box 1042, Bandung, Indonesia 40010
Or try to find list of IARU QSL Bureaus: http://www.iaru.org/iaruqsl.html
Or call me on high frequencies
To predict radio propagation (listen how far & strong): http://www.10mbeacons.com/
Get free software to learn Morse Code (CW): http://www.g4fon.net/

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Assessment from BAN-PT to Teknik Elektro ST-INTEN

2011-09-20T22:59:00.034+01:00

At September 19, 2011, my University Department (Electronic & Electrical Engineering / Teknik Elektro ST-INTEN) organized a visit of BAN-PT (Badan Akreditasi Nasional Perguruan Tinggi) to assess Our Department. BAN-PT is National Higher Education Accreditation Board which function to assess and give accreditation to higher educations in Indonesia according to defined service standard. BAN-PT representers were Prof. Dr. Ir. Maria Angela Kartawidjaja, MKom., and Dr. Ir. Anak Agung Putri Ratna, MEng.. Thank You very much for Your Kind Visit.

With humble, below are photos of the visit:

Communication Microphone for High Power Transmitter

2011-04-23T04:00:00.019+01:00

This is my design, and suitable for most of Amateur Radio & whatever transmitters which have power up to 100W PEP. The keys of this design compared to my previous designs are utilization of 2 RF filters located after condenser mic and voltage supply from power supply, and good ground connection connected from ground section of this mic preamp to ground installation at your soil. These are ways to suppress RF feedbacks from entering processing in transistor (2SC828).

This design has been tested using 100W transceiver with antenna SWR 1-1.5, and still produced clear voice. Mic used is cheap 2 leads condenser mic. Under is photo of this design after placed at PCB:

If you like to design microphone, especially mic that is used with high power transmitter, You have to be able to suppress RF that comes back to mic from antenna. One simple thing is to make your antenna SWR as small as possible (try SWR 1.0). With SWR 1.0, all of power generated by final amplifier would be dissipated at antenna, with higher SWR, there would be portion of power reflected back from antenna to final amplifier causes RF feedbacks on mic system. If your SWR already 1.0, but still You are having RF feedbacks, then You should utilize RF filter.

At this design, RF filter composed of one 27mH inductor (looks like black capacitor at photo), and two 1500pF ceramic capacitors. For higher transmitter power, You could experiment with more suppressing RF filter, logically: higher inductor value, and higher capacitors value. Utilization of grounded metal box, logically would suppress RF more. Try as far as You could until RF is not processed at mic circuit.

Components should be placed as close as possible, and cables should be as short as possible. These would reduce RF feedbacks. This is because long cables function as antennas.

+12-13.8 VDC could be taken directly from ordinary power supply.

22n & 10n are coupling capacitors. Their main function is to keep DC around transistor, while AC could travel from outside to transistor, and from transistor to outside. This unique capacitor characteristic could be used to determine audio tone of this mic system. Lower capacitor value tends to produce higher audio frequency (treble), and vice versa. Basic criteria when You are designing audio system for communication is Signal to Noise Ratio (SNR). Higher SNR, better, of course with clear signal without distortion. You could try to investigate Noise (QRM & QRN) on working frequency, and try to experiment with various audio tones, to try to make highest SNR, eg. if noise figure is bass, and Your audio tone is bass as well, so SNR would be low, so You have to make Your audio tone treble, so SNR would be higher, and Your audio would be more readable.

22n & 10n are green mylar capacitors.

To reduce fatigue, this mic could be designed as desk microphone.

Have a nice try and Good DX.

Photos of 2010 ST-INTEN Graduation Day, Bandung, Jan. 31st. / Foto-Foto Wisuda ST-INTEN 2010

2010-02-01T00:10:00.021Z

My university had XVII graduation day, Jan. 31st., 2010 in Bandung. The occasion was on Hotel Grand Pasundan. ST-INTEN is small university in Bandung, having 4 departments: Electrical & Electronic Engineering, Architecture, Informatics Engineering, and Civil Engineering. ST-INTEN established in 1984. ST-INTEN headed by Dr. Iksal Rachman, MT. since 2010. This year graduation, inaugurated 200 new scholars. Before being scholar, students have to finish around 150 SKS, or study at least 4.5 years. Engineering graduates in Indonesia have right to put ST. degree at the back of their name, stands for Sarjana Teknik, or in English: Engineering Scholar. Before 1993, engineering scholar in Indonesia degreed Ir. means Ingenieur (Dutch). Because of spirit of national standardization, Dutch degree no longer given in Indonesia. 2010 Graduation headed by Tita Cardiah, ST., MT., ST-INTEN alumnus, Architect, now lecturer in ST-INTEN.

We would like to thank All Persons involved as organizer of this graduation. Between them, we could mention our singing teacher tried to improve ST-INTEN Student Choir: Saut P. Manullang, SKom.. Saut is our fellow Scholar of Management Informatics graduated from neighbouring university UNIKOM.

2010 ST-INTEN Student Choir / PSM ST-INTEN 2010:
Choir Chief: Lena Hermawati
Choir Trainer & Conductor: Saut P. Manullang, SKom.
Choir Musician: Roosdiarto Rooskandar
Tenor: Dwi Santoso, Dadang Suhada, Rahmat Dianto
Soprano: Davy Lydia, Siti Sa'adah, Nadia Caesarina, Marisa, Endang, Webby Safitri, Intan Fauzia, Siti Solahiah, Badang Badariah, Derini Handayani, Suniarti Br., Amalia Nurbayani
Alto: Nuki Pa, Syifa Novasyifa, Nur Dawim, Tina Numbara, S. Nabila PAA., Rita Rahmawati, Silvia Saparini, Adelyna Rahmat, Wiwi Yuliani
Bass: Rezza MTD., Asep Salim Bk.

Several ST-INTEN Student Choir members graduated in 2010: Aditya Anggraini Perdani (Informatics), Wisnu Prayudhi (Informatics), Yogie Abdurakhman (Informatics), Cholid Fauzi (Informatics), Dinar Utomo (Electronic Engineering), Ariep Saeful Malik (Electronic Engineering), and Jejen Juanda (Electronic Engineering). Sorry I don’t recognize all of graduates names, but I could mention one more here: Agung Safwani (Electronic Engineering).

After downloading photos from this page (I suggest high resolution photos), You could print using your own photo printer or in commercial.

For All Graduates, Congratulation, and I pray you all good luck, good job and position in World, and keep study.

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Socialization of New ORARI Rules & Band Plan in Local Cibeunying / Sosialisasi Aturan Baru ORARI di Lokal Cibeunying

2009-10-19T08:24:00.037+01:00

In Saturday, October 17, 2009, ORARI Local Cibeunying organized socialization of new ORARI Rules & Band Plan based on new Indonesia Minister of Communications & Informations Technology Rule nr. 33/2009 dated August 31, 2009. Since this Rule release, ORARI under administration of Ministry of Communications & Informations Tech.. Before, ORARI under administration of Ministry of Transportation.

Basicly, this New Rules give ORARI more frequency allocation, and give ORARI members and member candidates several simplicities. These to accomodate more people to join Amateur Radio, and to support ORARI function as Amateur Radio Emergency Communication Aid. Good Amateur Radio Stations those still could operate in natural disaster situations (have stable antenna, uninterruptable power supply) could be operated as emergency radio stations connect large area of Indonesia. Before, most of ORARI members are in Siaga Class (YD & YG) who could not operate Phone in 40m band. With this new rule, YD & YG could operate CW, Phone, and Narrow Band Data (with SSB) nationally and internationally (DX) on 40m. This really increases ORARI capability to be Emergency Radio Stations. In many cases of natural disasters, eg. earthquakes, floods, and landslides, fix and mobile phone operations are down. While 40m band is ideal band to communicate every parts of Indonesia.

Before, frequency allocation for Amateur Radio in Indonesia in 40m was from 7.0-7.1MHz, now increased from 7.0-7.2MHz. Other simplicities given eg. lower speed of Morse examination, and increasing maximum power that could be utilized in every classes. This new Minister rule also ensures that DX stations from outside Indonesia could communicate with more ORARI members, not only with CW, but also with SSB, and Narrow Band Digital in DX bands (40m, 15m, and 10m).

Our sincere thanks to Willy Amwaludin (YD1GZA) as organizers chief and to All who have helped to organize this occasion.

Another attendants, sorry I could not recognize All:

R. Moch. Rachmat W. (YB1CY), Ir. Supra Dekanto (YB1KKK), Gatot Dewanto, SH. (YE1GD), Ir. Susilo S. (YC1BRT), Yaya Sudarya (YC1JYS), Saidjoer (YD1BGX), Dadang Sudiana, SE. (YC1KDD), Nunung Priyatna (YC1NUN), Roosdiarto Rooskandar, ST. (YG1CRR), Chitra Mayarani (YD1INA), Sunaryo (YD1CYO), Windy Elizabet (YD1LZW), Endang Kustiwa Eka (YB1EKA), Nana Suryana (YD1NAC).

Thank You very much All for coming.

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Designing 8.6-8.9 MHz AM Transmitter

2009-06-12T10:45:00.064+01:00

On this post, I am going to show how to design an AM transmitter. AM transmitter is one of the simplest modulation system. Other simplest modulation system is CW (Continuous Wave). AM produced by adding information signal to carrier signal. This process is called wave superposition. Carrier signal is signal that carries information signal to another location. Carrier signal also called RF (Radio Frequency). RF spreads from lowest frequency of MF (Medium Frequency): 300KHz up to highest of Satellite Frequencies (around 15GHz).

Simple AM transmitter made of 2 stages. Preliminary stage consists of oscillator, and 2nd. stage consists of RF amplifier. You could add/design your own succeeding stages, thus improve output power and transmission distance.

When information signal is in form of directly added digital signal, this modulation is called ASK (Amplitude Shift Keying). This AM transmitter could also modulated by BPSK, QPSK and AFSK (Audio Frequency Shift Keying), but those signals of BPSK, QPSK, and AFSK should be formed first. On this research, I modulate carrier with analog signal only, so called "AM".

On this design, I have designed oscillator with Colpitts Oscillator system that has good frequency stability (fulfil certain criteria first). Class A RF amplifier stage built as voltage amplifier that tries to increase output AC voltage compared to input. Because transistor characteristic also increases current, this voltage amplifier also increases output power compared to input. Both oscillator and RF amplifier use common emitter configuration and NPN transistors. Output impedance of AF/RF Class A transistor amplifier with common emitter configuration is around 50,000 (50K) Ohms. Output impedance of any amplifiers could be downed using impedance transformer. Most of audio speaker have 8 Ohms impedance. In this case, needed 50,000 Ohms to 8 Ohms impedance transformer. Most of transmitter antenna have 50 Ohms impedance. In this case, needed impedance transformer that could change 50,000 Ohms into 50 Ohms. Output impedance of AF/RF PushPull Class B or Class AB transistor amplifier with common emitter configuration is around 100,000 (100K) Ohms. PushPull Class B transistor amplifier formed from 2 Class B transistor amplifiers put in parallel, output impedance forms series (50,000 + 50,000 Ohms). PushPull Class B or Class AB transistor amplifier works more efficient, because reduces existence of Collector Voltage, but works less linear compared to Class A. In Class A, there is Collector Voltage existence (consumes energy), but this Class A more linear compared to PushPull Class B or Class AB. Class AB PushPull amplifier is modification of Class B PushPull amplifier in order to reduce crossover distortion. So from side of linearity, Class A is best, Class AB PushPull is second, and Class B PushPull is third.

In order to design an oscillator or RF amplifier, you would need oscilloscope at least. There are various kinds of oscilloscope, eg. 5MHz oscilloscope could measure RF up to 5MHz accurately. 20MHz oscilloscope could measure RF up to 20MHz accurately. If oscilloscope used above specification, oscilloscope could still show current curve/graphic, but could not measure voltage or frequency accurately. Eg. if you like to design VHF FM transmitter with frequency around 90MHz, you would need at least 5MHz oscilloscope and frequency counter that could measure 90MHz. Oscilloscope needed especially to measure voltage amplification accurately.

RF amplifier voltage amplification (on this design): 0.5Vpp/2.3Vpp= 0.217 . Current-gain bandwidth product (fT) of 2SC2053 is not mentioned in 2SC2053 DataSheet. In DataSheet only mentioned that 2SC2053 is transistor for VHF RF Amplifier. That's why I didn't doubt to use this transistor. Transistor with VHF purpose could be used at HF and AF. Maximum frequency of VHF is 300MHz, so I assumed fT little beat higher than 300MHz. Assumed 2SC2053 fT=400MHz ---> ßrf=400/8.8=45.45 so power gain/amplification=0.217x45.45=9.86 .
This means if earlier stage produces z Watts, this RF amplifier would increase power to 9.86z Watts.

RF amplifier principle is to amplify power from stage to stage. Succeeding stage should have more power compared to earlier. This principle could be used if you don't know fT of one transistor. Just estimate fT of that transistor, keep calculate, and after you've finished particular stage, just check its power. Its power should be more compared to earlier stage. If you are designing RF amplifier, you could check S (signal) meter at receiver that shows power strength of particular transmitter. If that stage fails to improve power, you should recalculate that amplifier. In my experiment, my receiver S meter showed increase signal when RF amplifier applied compared to "just" oscillator applied, means 2SC2053 fT=400MHz is good estimation, and this RF amplifier works to amplify oscillator power.

Whereever you like to assemble this circuit (or any RF circuits): on breadboard or PCB, there should be "certain" distance between lines. Between lines could not be placed too closed, due to RF absorption.

I've tried to modulate this transmitter with song signal from small radio/tape player. This "analog signal" is added/joined with carrier signal at oscillator output (at this design at oscillator collector). Because this radio/tape player produces sufficient power, I do not need impedance transformer. I only add 1Kohm variable resistor to adjust modulation index. Good AM transmitter when modulation index=1. If modulation index more than 1 (too much information signal power added), this transmitter would suffered "over modulation", while if modulation index less than 1, this transmitter would be in "lack of modulation". Result: Good for HF AM class, although would not as good as VHF FM transmitter, because HF is full of static noise (QRN) from electric power and full of signal from all over World (QRM), while VHF is relatively clearer. One good thing about HF transmitter: it could travel very far without satellite help because this band signal is reflected by ionosphere, even many times I've communicated with places with distance around 20 thousands kilometers away from my location with small transmitter power only (used HF).

This transmitter also completed with "long wire" antenna put in high location with big diameter of wire. One end of long wire connected to antenna sign at schema. Although this transmitter not completed with antenna impedance matcher, but existence of any good antennas would help electromagnetic wave to spread better. When transmitter output impedance, transmission line characteristic impedance, and antenna input impedance are match, voltage & current at load (antenna) would be maximized, thus maximize power at antenna and transmission distance. If impedances are not match, there would be standing wave at transmission line, causes not all power dissipated at antenna, but portion of power dissipated at transmission line (reflected power), thus decreases antenna effectiveness.

Negative polarity of DC supply connected to ground sign.

RFCs I use are fabricated RFCs. One way to make 0.5349µH (tuning coil):

Under are schema of this design and photo of this circuit built at breadboard (if you are not clear with schema, just left click at that schema):

AM modulation also used in TV transmission, to transmit Video, while audio is transmitted uses FM. So knowing principles to develop AM and FM transmitters are compulsories to develop TV transmitter.

Have a nice try, and hope you get more experience.

Reference to design oscillator and amplifier:
Horn, Delton T., "Transistor Circuit Design With Experiments", TAB Books Inc., 1985.

Reference to construct coil/inductor:
The American Radio Relay League, " The ARRL Handbook for Radio Amateurs 1995", 72nd.
ed., The American Radio Relay League, Newington, CT 06111, USA, 1994.

I finished this design on June 5, 2009.

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Photos of ORARI Local Cibeunying Conference 2009 / Foto-Foto Musyawarah ORARI Lokal Cibeunying 2009

2009-02-09T07:06:00.063Z

ORARI stands for Organisasi Amatir Radio Indonesia or in English: Indonesian Amateur Radio Organization. ORARI is part of IARU (International Amateur Radio Union) which logo in left. Almost every Amateur Radio Organization in various countries become member of IARU. Amateur Radios around the World use same standard in frequency allocation (only with slight differences), so We could communicate each other. ORARI established in 1968. ORARI divided into 10 areas (10 infixes), and each area divided into several locals. ORARI local Cibeunying belongs to area 1 (West Java & Banten Provinces).

This conference held in Bandung, February 8, 2009, in order to choose new organizers of this local. As this Conference head, is Willy Amwaludin, YD1GZA, thank you Sir for organizing. Conference room lent by Indonesia Scout Movement (Gerakan Pramuka Kwartir Cabang Bandung). Thank you very much for lending us such beautiful building.

This Local Conference also attended by Maj.Gen.(ret) IGK Manila, YB0AA, as Vice CEO of National ORARI. Representative from ORARI Area 1 management, is Aeng Setiawan (YB1CJG). Our sincere thanks for coming.

From this occasion, chosen as new ORARI Local Cibeunying CEO for 2009-2014: R. Moch. Rachmat W., YB1CY. Chosen as members of Counsellor: Dr. Ir. Budi Santoso (YB1BS), Gatot Dewanto, SH. (YE1GD), and Ir. Susilo S. (YC1BRT). Congratulations.

Another attendants (I couldn’t remember All):

Roosdiarto Rooskandar, ST. (YG1CRR), Undang Sudrajat (YD1BDC), Frihendani, SE. (YF1FRI), Soeparman (YD1BPK), Ir. Adang Sadikin (YC1BAR), Djoko Suryono R. (YD1OQY), Saidjoer (YD1BGX), Yaya Sudarya (YC1JYS), Ir. Sriyono (YC1JUN), Ir. Supra Dekanto (YB1KKK), Nana Suryana (YD1NAC), Dadang Sudiana, SE. (YC1KDD), Nunung Priyatna (YC1NUN), Danny Munadjat (YB1HKM), FX Handy Mulyana (YC1NZ), Drs. Agoes S. (YC1DOC), Jocky Chahyana (YC1JC), Windy Elizabeth (YD1LZW).

Thank You All For Coming.

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Photos of 2008 HME ST-INTEN New Members Inauguration / Foto-Foto Pelantikan Anggota Baru HME ST-INTEN 2008

2008-09-23T06:15:00.007+01:00

Photos under are medium resolution (each 150Kpixels/30KB) and already good to be printed in 3R size. You just have to left click, then right click on these photos, save, and print. To get higher resolution (probably you would like to print larger than 3R), please tell me your e-mail address of course with your clear identity, like your name, your department, and your NIM/identity number in ST-INTEN, and I would be very glad to send you higher resolution photo files (each 1.1 Megapixels/325KB). You could edit, resize, etc., use many photo editors. If internet connection is OK, please wait 3 days for reply. Printing cost (in commercial) is around Rp 1000.00 for 3R size or you could print yourself use photo printer. Printing result is good and smooth.

For All New Members, Congratulation, and I Pray You All Good Luck.

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Photos of 2008 ST-INTEN Elec Eng Dept & HME Training on "Maintenance & Repair of PC" / Foto Pelatihan Jur T Elektro & HME "Perawatan & Perbaikan PC"

2008-09-20T09:03:00.070+01:00

Electronic Eng Dept ST-INTEN together with Electronic Students Assc. (HME) have organized this free training. This was totally free of charge for attendants (ST-INTEN Students & public). Occasion held in our campus from Sept. 15-20, 2008. This occasion also with cooperation with ST-INTEN Electronic Laboratory.

Electronic Eng Dept ST-INTEN headed by Dr. Iksal Rachman, MT. since 2004, and ST-INTEN Electronic Laboratory headed by Ir. Dwiyanto, MT. This free training headed by Irdam Denni, ST., MT., ST-INTEN lecturer.

Organizers: Dr. Iksal Rachman, MT., Irdam Denni, ST., MT., Roosdiarto Rooskandar, ST., Zen Munawar, ST., MPd., Jejen Juanda, Rizki Ramdhani S., Zainuddin, Rasidi, ST., Puji Rahayu.

Trainers: Irwan Setyo Wibowo, ST., Roosdiarto Rooskandar, ST., Ir. Dwiyanto, MT., Drs. Ojo Suparjo, MSi., Adam Arif Rachman, Irdam Denni, ST., MT., Wahyu Haryadi, ST.

Attendants: Siti Sa'adah, Soni Suhendi, Isbaus Sururi, Yusuf Adam Nur, Ariep Saeful M., Adam Priawal W., Sriyadi, Panji Kurnia, Nendi Supriatna, Arief Nugraha, Indra Jaya, Vani Firmansyah, Lili Setiawan, Tantan Suntara, Saeful Anwar, Firman Nuryadin, Rangga Nugraha, Rachmi Santika L., Sidik Miftahul J.W., Jaka Setiawan (total of 20 attendants).

Photos under are medium resolution (each 150Kpixels/30KB) and already good to be printed in 3R size. You just have to left click on these photos, right click, save, and print. To get higher resolution (probably you would like to print larger than 3R), please tell me your e-mail address of course with your clear identity, like your name, your department, and your NIM/identity number in ST-INTEN, and I would be very glad to send You higher resolution photo files (each 1.1 Megapixels/325KB). You could edit, resize, etc., use many photo editors. If internet connection is OK, please wait 3 days for reply. Print cost is around Rp 1000.00 for 3R size or You could print yourselves use photo printer. Print result is good and smooth.

For All Attendants, Congratulation for finishing this training, and I pray You All Good Luck.

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Photos Of 2008 ST-INTEN New Students Reception / Foto-Foto Penerimaan Mahasiswa/i Baru ST-INTEN 2008

2008-09-01T04:46:00.051+01:00

Thank God, this year, my small university has accepted 125 new students in whole 4 departments: Informatics Engineering, Architecture, Electrical & Electronic Engineering, and Civil Engineering. August 29-30, 2008 were reception days. You could see several photos of this occasion downward. Hope You enjoy those. Reception opening attended by our only university Professor: Prof. The Houw Liong, Ph.D.. Prof. Liong is Professor in Physics. His preliminary Physics study was on Bandung Institute of Technology several decades ago. Prof. Liong also language translator for at least one technology book I used. ST-INTEN headed by Drs. Harry Setiabudi, since mid of this year (2008).

Photos under are medium resolution (each 150Kpixels/30KB) and already good to be printed in 3R size. You just have to left click on these photos, then right click, save, and print. To get higher resolution (probably you would like to print larger than 3R), please tell me your e-mail address of course with your clear identity, like your name, your department, and your NIM/identity number in ST-INTEN, and I would be very glad to send you higher resolution photo files (each 1.1 Megapixels / 325KB). You could edit, resize, etc., use many photo editors. If internet connection is OK, please wait 3 days for reply. Printing cost (in commercial) is around Rp 1000.00 for 3R size or you could print yourself use photo printer. Print result is good and smooth.

For All New Students, Congratulation, and I pray You All Good Luck, Study Well Please, so You Would Be Someone Independent, Extraordinary Between Earth Citizen.

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Photos of 2007 ST-INTEN Graduation Day, Bandung, Dec. 22nd. / Foto-Foto Wisuda ST-INTEN 2007

2007-12-23T00:05:00.067Z

My university had XVI graduation day, Dec. 22nd., 2007 in Bandung. The occasion was on Hotel Grand Aquila. ST-INTEN is small university in Bandung, having 4 departments: Electrical & Electronic Engineering, Architecture, Informatics Engineering, and Civil Engineering. ST-INTEN established in 1984, now accredited B by government accreditation board. This year graduation, inaugurated 121 new scholars. Before being scholar, students have to finish around 150 SKS, or study at least 4.5 years. Engineering graduates in Indonesia have right to put ST. degree at the back of their name, stands for Sarjana Teknik, or in English: Engineering Scholar. Before 1993, engineering scholar in Indonesia degreed Ir. means Ingenieur (Dutch). Because of spirit of national standardization, Dutch degree no longer given in Indonesia. ST-INTEN headed by Drs. Inu Hardi Kusumah, ST., MPd. since 2004. 2007 Graduation headed by Ir. H. Suwarna, ST-INTEN electronic eng. alumnus, and now lecturer in ST-INTEN.

We would like to thank all persons involved as organizer of this graduation. Between them, we could mention our singing teacher tried to improve ST-INTEN Student Choir: Saut P. Manullang. Saut is our fellow final year student of Management Informatics of neighbouring university UNIKOM. Hopefully Saut would be Computer Software Scholar in 2008. We pray for that. Another help came from Aprian. Aprian played as choir pianist. Aprian is Law student in STHB, private university in Bandung focusing on Law studies.

2007 ST-INTEN Student Choir / PSM ST-INTEN 2007:
Choir Trainer & Conductor: Saut P. Manullang
Choir Musician: Roosdiarto Rooskandar, Aprian
Tenor: Roosdiarto Rooskandar, Cholid Fauzi, Rizal K, Jejen Juanda, Yasa, Yogi
Soprano: Lestari, Davy Lydia, Lena Hermawati, Redi, Siti, Intan
Alto: Aditya, Fitri, Lulu (foreign student from Timor Leste)
Bass: Wisnu, Ariep Saeful M., Sriyadi, Arman S., Dinar

Several ST-INTEN Student Choir members graduated in 2007: Elsa Elvandari (Informatics), Desivita Amelia Kansil (Informatics), Netta Agustina Herdi (Informatics), and Dewinta Kusumawaty (Informatics). Sorry I don’t recognize all of graduates names, but I could mention several more here: Wiwiek Susilowati (Electronic Engineering), Yeniwati (Electronic Engineering), and Erwin Supiyanto (Electronic Engineering).

Photos under are medium resolution (each around 150Kpixels/30KB) and already good to be printed in 3R size. You just have to left click on these photos (go to photos storage), right click on these photos, save, and print. These photos taken several days before Graduation Day, and at Graduation Day. To get higher resolution (probably you would like to print larger than 3R), please tell me your e-mail address of course with your clear identity, like your name, your department, and your NIM in ST-INTEN, and I would be very glad to send you higher resolution photo files (each 1.1 Megapixels/325 KB). You could edit, resize, etc., use many photo editors. If internet connection is OK, please wait 3 days for reply. Printing cost (in commercial) is around Rp 1000.00 for 3R size or you could print yourselves use photo printer. Printing result is good and smooth.

For All Graduates, Congratulation, and I pray you all good luck, good job and position in World, and keep study.

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Last 4 photos: Choir Chief: Aditya, Choir Secretary: Lena Hermawati, Choir Trainer & Conductor: Saut P. Manullang, Choir Pianist: Aprian

Photos of 2007 Indonesia Anniversary Day Celebration / Foto-Foto Peringatan HUT Indonesia ke-62, 17 Agustus 2007

2007-08-17T18:00:00.020+01:00

In August 17, 2007, Republic of Indonesia commemorated 62nd. of its anniversary. Republic of Indonesia declared in August 17, 1945. The area extends from Sabang to Merauke City. It is the same extent as Lisbon to Ural Mountain in Europe.

Indonesia Independence Day celebrated everywhere in Indonesia with grateful. Under are photos of simple celebration in my residence area. Just medium resolution photos (150KPixels/30KB). These medium resolution photos already good if printed in 3R size. If you like higher resolution (1.1 MPixels/300KB), you could ask these photos to me. Please tell me your identity, your email address, and which photos you like. Hopefully, I'll send you high resolution photos (1.1 MPixels). Happy Anniversary Indonesia. May God Bless Indonesia, and Indonesia Be Bless For Universe & Other Nations.

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Love Your Plants & Trees & Make Greener Cities

2007-03-16T10:02:00.003Z

Do you realize that primary sources of oxygen for living creatures, like human, animals, and plants, now become rare? Because of growing Earth population, jungles, forests, parks, gardens, yards, and plantations changed into buildings. Number of plants and trees around the World become less than for example 50 years ago. Together with trees diminishing, free oxygen produced by plants also diminished, thus endanger our lifes and health.

In photosynthesis process: carbon, heat, and sunlight absorbed by leaves, and changed into glucose, water, and oxygen. Exactly in chemistry nomenclature like this: 6CO₂ + 12HO + solar energy —> C₆H₁₀O₆ + 6H₂O + 6O₂. Glucose (sweet) produced, could be sensed by eating fruits. Proofs about heat absorbed, and oxygen produced could be sensed when you pass big parks in daytime. Temperature suddenly dropped, and you feel fresh, because environment heat absorbed & you get more oxygen supply. Another proofs from that photosynthesis reaction, could be searched from your High School Biology lesson.

So how about now? Earth with 6 billion population, and always grows? Of course if we all would like to survive and healthy, we have to add our number of trees. Stop wood logging. If every Earth citizen plants 1 tree, there would be new 6 billion trees. Amazing.
Another reaction of photosynthesis is absorption of carbon. Carbon produced by machinery combustion, by kitchen burner, etc. could be absorbed by trees if We have trees/plants. If we don’t have trees/plants, those carbons in stable form of CO₂ or unstable form of CO would just fill space between ground and high atmosphere, makes shield, makes difficult for heat to go out from Earth, called Global Warming Effect. So love trees, will reduce Global Warming Effect, because leaves absorb carbon produced from combustion. More We have trees like in jungles, more to be absorbed.

So behaviour like change your green yard into building is not good. Keep portions of your residence for plants to grow.

Another benefits of loving trees rather than buildings, are you would not get flood, landslide, and even trees could reduce earthquake effect. Tree roots especially big ones hold soil in slanting from sliding. When earthquake happens, tree roots could help us by holding soil from sliding also. In beaches with Tsunami potential, forests of mangrove could block Tsunami waves from destroying inner areas. In last December 26, 2004 Tsunami, cities with open beaches like Meulaboh and Banda Aceh were totally and half destroyed. 100% of Meulaboh was destroyed & 55% of Banda Aceh was destroyed. But there were several towns in Simeulue Island, also head to head with Tsunami source, only experienced destruction less than 5%. Amazing. That was because Simeulue beaches still covered with mangrove forests. Simeulue peoples didn’t change their mangroves to hotels and buildings. Indonesia and many countries in World have Tsunami potential: from Japan to Solomon, from California to Chile. So from now on, protect our lands by covering all beaches with plants & mangroves.

Trees also help us keep our water source. In rain seasson, area with many trees absorbs rain water, form water reserve underground. In dry seasson, that water reserve could be utilized. If we have enough water reserve, rivers and wells won’t be drained. Existence of water in rivers and wells are absolutely important for our life, for electricity, etc..

So from now on, love plants and trees. If we love another God creatures like them, they will protect us reciprocally. In the photo above, is fruit tree (Psidium Guajava). Beside gives cool temperature, that tree gives good scenery. Psidium Guajava produces fruits that contain plenty of Vitamin C. If you have this kind of tree, you don’t have to buy vitamin supplement. Because of high content of Vitamin C, this kind of Psidium Guajava could prevent you from having sicknesses like Dengue Fever. You could be bitten by vector mosquito, but your body plus Vitamin C from this fruit would form strong antibody.

In big city like Jakarta, Indonesia capital, with land area around 750 km², urbanization becomes huge problem for environment management. High number of urbanization makes this city changed its green areas to offices, factories, and housings. These function changes become problems for Jakarta like: killing flood, killing diseases, most polluted, and highest temperature. Source of this huge urbanization is unbalance distribution of investment. Jakarta controls 50 percent of Indonesia money, causes Jakarta as main destination of job seekers. So, main priority to control Jakarta environment problems is concentrating most infrastructures and investments outside Java and Sumatera (crowded islands). Jakarta population (night: 8 million, day: 12 million) should be reduced to 4 million in night and day, in order this city to function nice and comfortly. Now it’s time to think about relocation of Indonesia capital to outside Java and Sumatera, and move several Jakarta investments either. Rather than develop new hotels for tourists in Jakarta, for example, I think better build them in Central & East Indonesia, so seeking jobs citizen not concentrate in Java & Sumatera. Nation budget should be distributed according to area size. Sounds easy. I hope this could be lesson for another big cities around the World before disasters come.

Another benefit of green country is tourism. With green country, I’m sure many tourists would come, and more tourists come means more income.
So you see, too many benefits of loving plants and trees. From now on, start plant more plants, which would give you most benefit, and let’s make greener, cooler, fresher, and more beautiful Earth. I pray to God for that.

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The Danger of Developing Nuclear Power Plant in Indonesia & Other Countries

2007-03-16T09:09:00.002Z

Indonesia government starts looking for alternative source of electric power energy, such nuclear energy. But I do not think that’s a good idea, because of specific conditions of Indonesia, the area with highest earthquake and landslide numbers in World. Nuclear power plant produces at least 55 MegaWatt, and to produce 55 MW electricity, needed numbers of Uranium 235.

Those numbers of U-235 equal with 3x nuclear bomb power downed in Hiroshima. So when that nuclear power plant operated, and earthquake or landslide happened, usually with high Richter Scale, that nuclear power plant would leak, and the radiation would kill more than 10 million peoples and causes permanent injury to millions others.

No building or structure in World could against strong earthquake, always has cracks. For countries with high earthquake and landslide numbers, like Indonesia, Philippines, Taiwan ROC, and Japan, of course have to develop other kinds of electric power plants, like geothermal, sun, wind, sea wave, garbage, biomass, and dozens others, which have less risks.

Peoples of World still anxious about Chernobyl accident in 1986, killed many peoples, caused permanent injuries to many others, and causing high radiation up to now to Chernobyl surrounding areas. Observer in Sweden in 1986, reported danger level of nuclear radiation reached Sweden when Chernobyl blowed. Careless plan in utilization of huge nuclear energy could destroy human civilization. I pray to God, these nuclear disasters would not happen more anywhere in World.

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Safety In Oil And Gas Exploration

2007-03-16T08:50:00.003Z

In many parts of the World, oil and gas still explored and exploited. Based on gas exploration accident in Porong, East Java, Indonesia, I write this article, with hope there would be no more such accident.

Exploration terminology is for first step before oil and gas could be produced. Exploration includes estimation where the location is, and complete study of risks, and costs that would be expensed. One important thing in oil and gas exploration is study of Earth sedimentation. From the East Java (Porong town) case, drilling site stands above thin hard skin of Earth, caused drilling process reached Earth magma. This is the first problem. Second problem and causing major disaster is drilling site stands above delta area. Delta area is area between mouths of 2 near rivers, contains much of water, even best place for agriculture, because of its water content.

Drilling above delta of course produces water. In Porong case, drilling site not only above delta, but it is to close to vulcanic chain. Lack of preliminary sedimentation analysis caused drilled well producing hot water from the well, uninterrupted, and constant hot. Hot water mixed with soil producing huge number of mud, drawning many houses and factories around site with 4-5 meter deep. That's why sedimentation analysis is absolute before every oil and gas exploration. Material out from drilling well could be unexpected & very destructive.

If we like to drill deeply in land and sea, we must take attention of sedimentation under. Avoid area already signed as vulcanic area. In vulcanic chain around the Earth, Earth skin relatively thin, and if we drill just shallowly, we will suddenly contact Earth magma. In World, vulcanic area form chain, there is chain from Sumatera, Java, Nusa Tenggara, goes to Philippine, Japan, Hawaii, West North America, goes down to West South America, called Pacific Ring. There is vulcanic chain from Iceland goes South in the middle of Atlantic Ocean. Drilling for oil or gas on this chain is absolutely forbidden.

Another risky area is area contains water or another intruding material. Intruding material would make difficult for oil and gas refinery later.

In oil & gas exploration, then oil & gas production, surrounding nature environment should also be taken as concern. Nature beauty and lasting are very important in many aspects, from oxygen supply, tourisms, etc.. So try open as small as area for drilling in order to keep as large as nature area maintained. Maintain its natural beauty.

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Effect of Sun Radiation to Radio Propagation & Earth Temperature

2007-03-16T02:35:00.002Z

In early 2006, I made hypothesis that Sun radiation not only affects atmosphere ionization, but also affects Earth temperature. Sun radiation consists of lights in several wavelengths. From infrared with longest wavelength (lowest frequency) to ultraviolet (UV) with shortest wavelength (highest frequency). UV from Sun causes atmosphere molecules to release their electrons (called ionization). This ionization forms electron mirror in the atmosphere, reflects High Frequency (HF) radio wave transmitted from ground to far location at the other side of Earth. Part of atmosphere already ionized, called ionosphere. Atmosphere ionization varies from year to year, follows Sun radiation intensity. Sun radiation reaches maximum averagely every 10.7 years. In between Sun maximum radiation, there is Sun minimum radiation. Sun radiation reaches minimum averagely every 10.7 years also.

According to observation datas, Sun maximum radiation happened in middle of 1958, early 1969, end 1979, mid 1990, and early 2001. Next maximum Sun radiation I predict hopefully would happen in change between year 2011 and 2012. Around Sun maximum radiation time, High Frequency radio propagation is absolutely best. Long distance communication more than 20,000 km away, uses High Frequency is absolutely easy, lasts long, and signal is strong. On the contrary, around Sun minimum radiation time, HF radio communication distance is limited, only capable of short distance communication. Sun maximum radiation like “heaven” for DXer, when DXer could contact so many faraway stations, so fascinating. But for everyone who think, Sun minimum radiation is not bad also, because they think “minimum would be followed by maximum, and minimum Sun radiation is time to rest equipments, and prepare equipments face maximum Sun radiation”.

In mid 2006, exactly on early August 2006, Sun radiation reached minimum. HF radio propagation was very limited. My hypothesis was proven. Minimum radiation from Sun also lowered Earth temperature. Around mid 2006, Indonesia used to have dry seasson, and that 2006 dry seasson was tremendous (extreme dry and long) dry seasson. Many places in Indonesia suffered lack of water, usually not (at the same period). That because heat from Sun decreased followed decreasing Sun radiation. Minimum heat from Sun caused sea temperature too low to form cloud, caused lack of rain, especially on the winter area. Second proof was tremendous (extreme) cold winter in Northern Hemisphere around January and February 2007. Helsinski and North part of mainland USA experienced temperature down to -20°C (called ice storm). That was because heat from Sun still minimum also.

So Sun radiation not only affects radio propagation, but also affects Earth temperature. Scientifically we should think Sunlights from infrared to UV as kinds of energy. Infrared with lowest frequency has lowest energy. UV with highest frequency has highest energy. That energy (in ionization process) forces outest electron in atmosphere molecules to separate, forms electron layer, especially by Ultraviolet (UV). In heating occasion, Sunlight reaches molecules in Ground, absorbed by Ground molecules (called endoterm). Of course more radiation from Sun causes more heat absorbed by Ground (increases Earth temperature). Sounds simple, but important for living creatures preparation. This knowhow could be added to our knowhow to predict World climate and weather (Meteorology) in future.

Because of that proven hypothesis, I predict around year 2011 and 2012, not only HF radio propagation would be the best, but Earth temperature would raise little beat, would cause more cloud formed from hotter sea. That more cloud would cause more rains, more hurricanes, more typhoons, more floods, more landslides, and more heat strikes around 2011 & 2012 (all contrary to mid 2006 situation). I write this so we all could prepare better. We have to maintain our trees and plants so we won’t have tremendous floods and landslides. We have to maintain our trees and plants so heat strikes won’t be too extreme. (Trees could absorb heat, please read my other article on this blog).

Keep learn and research, and we all could share our common sciences and technologies, and use all those knowhows for common progress and peace of Earth. I pray to God for those.

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Amateur Radio Antennas System & How To Avoid Lightning

2007-03-16T02:00:00.006Z

In wireless telecommunication, two important aspects are how effective and efficient your antenna is. In this article, I would like to share several tips on how to make your antenna more effective and efficient. My explanations valid for general, could be used not only for Amateur Radio station, but also for every equipments use antenna to spread/receive signal. My explanations derived from my own antennas.

I am using 3 antennas for DX. In 28 MHz, I use 3 el. Yagi, and 2 inverted Vs for 3.5, 7, and 21 MHz. At the photo, top of inverted Vs hang slightly under 3 el. Yagi. One of inverted Vs serves 2 bands: in 7 MHz works as 0.5 wavelength, and in 21 MHz works as 1.5 wavelength. Second inverted V works for 3.5 MHz. Both inverted V fed by only 1 coaxial. To understand why 1 coaxial could serve 2 antennas, you should read antenna handbook. It’s the matter of resistance of energy. Inverted V works omni directional.

Conductor used for antenna should be as conductive as possible. In my case, for my Yagi, I use big diameter of alumunium, and for inverted Vs, I use big copper wire. These are to ease current flows inside antenna, thus strengthen radiation. Coaxial cable used to feed antenna should be as short as possible. This is to minimize loss of signal inside coaxial cable.

Another consideration is about height of antenna. Put antenna too high is not good, because too high antenna means too long coaxial cable (big loss). But too low antenna is not good either, because signal from/to antenna would collide obstacles around antenna. Best consideration is putting your antenna so antenna could maximize signal goes to/comes from sky & reflection by ground (sky & reflection by ground wave).

Another tip like: your radiator (antenna elements) should be as long as possible. Antenna which radiator too short, would not radiate anything to sky. Long better. With long radiator (and match impedance), energy transferred from/to your transceiver would be maximized. Another tip like: use bigger diameter of coaxial cable, like RG8 rather than RG58. Bigger coax will ease electron to flow inside.

Give protection to your transceiver from lightning storm. The way is absolutely easy, and can protect your expensive transceiver from being destructed. Prepare big diameter cable, attach that cable to metal body of your transceiver. The other end should be connected to metal water pipe (if that water pipe buried deep), or other end of your cable should be buried deep into ground, at least 3 meters deep. When lightning attacks, positive pole from that lightning would try to find absolute negative. Ground cable acts as absolute negative. Positive lightning bound to absolute negative, and gets rid from expensive components inside your transceiver. So ground your transceiver now, and keep receive and transmit although you are in the middle of lightning storm. Your transceiver would be wonderly saved, you don’t have to waste time waiting storm over, and you don’t have to unattach your coaxial cable in lightning storm.

Last, keep away your antennas system from rust or corrosion. You could give anticorrosion paint (eg. zinc) to your antennas system, and give another materials that could block oxygen and salt from touching the metal.

With all these tips, thank God, I did so many DX (international communication) up to 20,000 km away (half around Earth). So, Good DX, and hopefully you would get as many as DX stations as possible, especially in the increasing era of atmosphere ionization now, up to maximum atmosphere ionization around 2011/2012.

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Free Design of Cheap & Nice Microphone for Amateur Radio, CB, Broadcasting, TV Station, etc.

2007-03-16T01:49:00.015Z

First, for low power transmitter:

This is partly my design. Original design was not like this. With years of modification, while I did many other things, I came to this design. This microphone, if you follow my instructions, will work satisfying from side of money and quality. This mic is designed to be used together with around 10 Watts maximum transmitter output power. If you use more than 10W, erratic and RF feedback most probably would come to your microphone. This feedback causes your modulation sounds distorted. But if you follow my instructions, comes out voice would be crystal clear, high quality audio. So, in big powered Broadcasting and TV Station, this mic only useful in studio, before relayed to big powered transmitter station far from studio. But if you have maximum around 10W Broadcasting or TV Station transmitter close to this mic, this mic hopefully good one.

Transistor used: 2SC828, could be not available in your country. You could change with the equivalent of 2SC828: BC167A, BC167 or MPS6566, or whatever you could get from Transistor Data & Equivalent Book.

470n capacitor is mylar one. Mylar is capacitor with plastic cover. Type of 470n mylar capacitor I use is the one with transparent yellow plastic cover. The other type of mylar has dark green colour. While both 270pF capacitors are ceramic. While capacitors with + & - sign are both electrolytic capacitors. These specifications to provide best result. But if too difficult to get, you could try with other capacitors as long as same values (with slight difference on result of course).

Mylar capacitor used to provide high quality audio, while both 270p ceramics used to absorb as many as RF feedback, so RF feedback doesn't come to circuit.

For best result, this circuit should be put in metal box, also to prevent RF feedback. Best shape for this mic design is desk microphone. With desk mic position, you could reduce fatigue. From the output of this circuit to your transmitter, should use coaxial cable, also to prevent RF feedback. Length of your coaxial should be as short as possible. DC supply needed by this circuit, could be provided by your power supply. DC supply cable should be as short as possible also. All compulsories above to prevent RF feedback enters circuit and enters your transmitter. Best cable between condenser mic to this circuit also coaxial, as short as possible.

If you've finished with assembly, now it's time to set variable resistor (VR) at output and your transmitter audio level. Best indicator to do this uses another transceiver to monitor. Try to speak while set VR and transmitter audio level. Usually, if VR and audio level too opened, this mic will be overmodulated. Lower both down, until out voice becomes clear. Another good indicator to set VR and audio level use transceiver output power indicator, especially if work with SSB. High quality audio resulted when your indicator needle runs lightly and no tremble. If VR and audio level set too high, needle movement would be heavy, and tremble.

According to my experience, your antenna should be match with your transmitter (SWR 1:1), because if antenna doesn't match, there would be great amount of RF goes back to microphone causes RF feedback. Another tips: antenna cable (coaxial) should be placed far from microphone also to avoid RF enters microphone system.

Now, for high power transmitter (up to 100W), 2 designs:

Design nr. 1:
This is completely my design, from calculated all transistor bias voltages, etc.. With this design, high fidelity audio output is hopefully. This design uses 600 ohm dynamic microphone, most dynamic mic in market & in use. To surpress RF enters this mic, DC supply provided by 3V dry batteries, because if DC supply provided by ordinary power supply, strong RF feedback from high power transmitter would come to this mic. Photo below shows design process used breadboard:

More under is schematic diagram of the design:

Transistor used is 2SC828. Equivalents are: BC167, BC167A, MPS6566, or whatever you could get from Transistor Data Book. 220nF capacitor is mylar one. I use mylar with transparent yellow cover. Both 270pF capacitors are ceramic. These capacitors to ground RF feedback before enters circuit. While capacitors with + and - sign are both electrolytic capacitors. Dry batteries used could be 2x1.5V small size or big size, but I suggest big ones, so they would last longer.

Use shortest coaxial cable possible from mic to transceiver to avoid RF feedback. When you ready with the circuit, try to set Variable Resistor (VR) in this design and audio level in your transmitter, while seeing your transmitter power indicator. Set both till needle movement is light and no tremble (stable). You could use another receiver to help you monitor the result. I design this mic in the form of desk microphone so could reduce user’s fatigues. I hope the result satisfies you.

Design nr. 2:
For high power transmitter up to 100W, this design is quite simple (just for emergency. I suggest design nr. 1). I’ve experimented with single dynamic microphone. Dynamic microphone is microphone has moving coil at the back of front membrane. Around moving coil, there is magnet. Moving of coil causes various magnetic field to coil wire. This causes coil wire has various AC voltages. You could search for new or old dynamic microphone probably ex karaoke or given together when you buy recording means. Disassemble the dynamic microphone. Most of dynamic microphone have 600 ohm impedance. Ideally, mic and transmitter have same impedance. Unmatch between both impedance will cause unsufficient modulation pulled to transmitter. In my experiment, my 600 ohm mic gives sufficient audio voltage to transmitter.
After that, dynamic microphone tone could be set by adding tube in front of mic that could be set on its length. Use another radio to monitor result. Set tube length till out voice becomes as you like.

I design this mic in form of desk microphone. This would ease communication, and reduces fatigues.

Sounds cheap but nice, right? Find out yourself. Good DX.

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Bandung & Indonesia Tourisms

2007-03-16T00:01:00.016Z

Bandung is one of beautiful small cities in World. The lowest point of this city is around 685 m. asl.. The highest point is around 900m.. The population is about 2 million peoples. This city is cool, and not so crowded. You still could see many big parks inside the city. This city was planned in the era of Dutch colonization around 1810, as resting city in the journey between edges of Java Island.

About 18km. North of this city, there is Mount Tangkuban Perahu. This mount is volcano. Last big eruption happened around 1920, my grandfather era. Of course every volcano has crater(s). Visitors could walk very close to the crater, even in some of its craters, visitor could touch bottom of crater, feel Earth magma, probably for first time.

About 6km. North East of Volcano Tangkuban Perahu, there is Ciater hotspring. This hotspring occured because of volcanic activity combined with existence of water source. You could swim, take a bath, or take 1 or 2 nights accomodation.

Inside Bandung, in North edge, you could visit Ir. H. Juanda National Park. This sanctuary consists hundreds of tree species, in area several km. square. This National Park is also camping ground. With very cheap, visitors with their own camping equipments could stay in this natural beauty for several days. Close to Ir. H. Juanda National Park, there is Dago Tea House. Dago Tea House is a high point in Bandung, so visitors could see most of Bandung City downward. Still inside Bandung, the city parks eg.: Taman Cibeunying, Taman Lalu Lintas, Taman Maluku, Taman Cilaki, Taman Tegallega, and Lebak Siliwangi.

Environmental lovers in Bandung working very hard to keep these parks alive, because they are tourism and environmental assets. Visit Bandung of course chance to get more fresh air and more oxygen. Photosynthesis process in plant absorbs heat, carbon, and produces oxygen: 6CO₂ + 12HO + solar energy —> C₆H₁₀O₆ + 6H₂O + 6O₂. That’s why when we pass big parks, we feel cooler and fresher. That’s proof that photosynthesis absorbs heat and produces oxygen. Grow as many as plants and vegetations as possible, of course one of the way to reduce Earth heat and reduce earthquake effect. We could reduce global warming effect by loving to grow plants. Plants are somekind of natural air conditioner. If every Earth citizen plants one tree, there would be new 6 billion trees. Imagine how much temperature could be downed, how much cheap oxygen could be produced, and how many floods and landslides could be avoided. If we love another God creatures like trees, trees would keep human species alive, healthy, and well.

Bandung also has 2 others nice camping grounds in the North and South West. In the North, at the altitude of 1400 m. asl., you could stay at Cikole. In the South West, at altitude 1600 m. asl., you could stay at Ranca Upas. Of course, stays in these 2 places, especially in Java winter (around June & July) could freeze you down.

Bandung also having many starred and economy hotels. This city could be reached from international city of Jakarta by several ways: airplane, 1 superhighway (take 2 hours), several ordinary roads, and train. Of course, my suggestion is choose the cheapest and safest way. Bandung airport still too small to be landed by big jet, so Bandung airport serves mainly domesticly.

To see many tourism places in Indonesia’s 33 provinces, you could go to: http://www.indonesia-tourism.com/. I hope you wouldn’t be disappointed. Feel Indonesians hospitality.

So you see, thank God, many places are beautiful in Indonesia. Indonesia has Bunaken beautiful shore in North Sulawesi, Manokwari beautiful shore in West Irian Jaya Province, and probably hundreds of other untouched shores along these 17.5 thousand islands archipelago. Would like to see one of Indonesia most North islands named Miangas Island (Lat: 5.559°N Long: 126.587°E) from satellite, click here: Our Beloved Miangas Island.

Best time to visit Indonesia is in our dry seasson. In rain seasson, wind and rain become so strong, make difficult for transportation, and several of our areas have floods & landslides. In rain seasson, sea waves become so high make sea transportation difficult. Indonesia divided into 2 large areas: South Indonesia and North Indonesia. South Indonesia: Lampung, Java, Bali, & Nusa Tenggara have rain seasson from November - March. Safe times to visit South Indonesia are between April - October. Between April - October, South Indonesia has dry seasson: sea is calm, sky is bright and blue, everything calm & beautiful. And time between April - October coincides with Summer Holiday in Northern Hemisphere. What a good time to visit South Indonesia. Hopefully, domestic transportation is safer from April - October in South Indonesia. To visit Norther Indonesia: North Sumatera, Toba Lake, Bunaken, consider yourselves about dry seasson on those areas.

Keep scan & come like Tarzan explore our jungle.

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Photos of 2006 ST-INTEN Graduation Day, Bandung, Dec. 18th. / Foto-Foto Wisuda ST-INTEN 2006

2006-12-19T08:55:00.037Z

My university had XV graduation day, Dec. 18th., 2006, in Bandung. The occasion was on Hotel Savoy Homann. ST-INTEN is small university in Bandung, having 4 departments: Electrical & Electronic Engineering, Architecture, Informatics Engineering, and Civil Engineering. ST-INTEN established in 1984, now accredited B by government accreditation board. This year graduation, inaugurated 167 new scholars. Before being scholar, students have to finish around 150 SKS, or study at least 4.5 years. Engineering graduates in Indonesia have right to put ST. degree at the back of their name, stands for Sarjana Teknik, or in English: Engineering Scholar. Before 1993, engineering scholar in Indonesia degreed Ir. means Ingenieur (Dutch). Because of spirit of national standardization, Dutch degree no longer given in Indonesia. ST-INTEN headed by Drs. Inu Hardi Kusumah, ST., MPd. since 2004.

We would like to thank all persons involved as organizers of this graduation. Between them, we could mention our singing teachers tried to improved ST-INTEN Student Choir: Ir. Tohom UP. Sitompul, Drs. Thomson, and Saut P. Manullang. Saut is our fellow student of Management Informatics of neighbouring university UNIKOM.

Photos under (except 5 photos in advance) are medium resolution (around 150Kpixels/30KB) and already good to be printed in 3R size. You just have to left click on these photos (go to photos storage), right click at photos, save, and print. These photos taken several days before Graduation Day, Dec. 17, & 18. To get higher resolution (probably you would like to print larger than 3R), please tell me your e-mail address of course with your clear identity, like your name, your department, and your NIM in ST-INTEN, and I would be very glad to send you higher resolution photo files (each 1.1 Megapixels/325KB). You could edit, resize, etc. use many photo editors. If internet connection is OK, please wait 3 days for reply. Print cost (in commercial) is around Rp 1000.00 for 3R size or you could print yourselves use photo printer. Print result is good and smooth.

For All Graduates, Congratulation, and I pray You All Good Luck, Good Job, and Position in World, and keep study.

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Last 4 photos: Author: Roosdiarto Rooskandar, ST., Choir Chief: Septian Hornas Lumeno, Choir Secretary: Aditya, Choir Trainer & Conductor: Saut P. Manullang