Monday, March 2, 2015
Kapasitor 220 pF 2KV, 820 pF 2KV, 1200 pF 2KV
Friday, February 27, 2015
Transistor FET IRFP 150 N
IRFP 150 N , buatan International Rectifier
Berfungsi sebagai Transistor mosfet RF Amplifier
konfigurasi push full bisa 100 Watt, tegangan 13.8 V
Dijual Transistor FET, IRFP 150 N, harga satuan Rp. 12500, dijual 1 paket isi 4 buah
SMS : 081298803808
email : radiobekas@gmail.com
Wednesday, February 18, 2015
IF Warna Biru
IF Biru merek Good Plan
Berfungsi sebagai Band Pass Filter ( BPF)
Dijual Coil IF Warna Biru, Rp 2500, minimal 1 paket isi 10 buah
SMS : 081298803808
email : radiobekas@gmail.com
Thursday, February 12, 2015
Trimer Kapasitor 100 pF
Bahan keramic
Dijual Trimer kapasitor 75 pF, harga Rp 2500, dijual 1 set 10 buah
email : radiobekas@gmail.com
IF Warna Biru
IF Biru, merek Good Plan
Varco 275 pF
Friday, February 6, 2015
Radio National R 4250 Y, NOS No. 2
Radio 2 band, MW (530 KHz - 1600 KHz, Medium Wave) & SW (2.3 Mhz - 7 Mhz, Short Wave)
Dijual radio National R 4250 Y , NOS, harga 250 rb, belum termasuk Ongkir.
SMS : 081298803808
email : radiobekas@gmail.com
Monday, February 2, 2015
Friday, January 30, 2015
Radio National R 4250 Y, NOS No 1
National Model R 4250 Y
Power Source : Battery 2 "D" size 3V
PT national Gobel Indonesia
MW : 530 - 1600 KHz
SW : 2.3 - 7.0 MHz
Call :08811350050
Terjual (sold out)
Friday, January 23, 2015
Collins Filter
Thursday, September 22, 2011
Wednesday, October 6, 2010
Thursday, September 30, 2010
Tuesday, August 3, 2010
Thursday, July 29, 2010
LM 386 74 dB

LM386 is very popular IC also in Japan. It is used in Radio receiver. The power of it (500mW) is enough for the personal use. But sometimes, the gain of it (40dB) is not enough. Especially the direct conversion receiver depend on all of its gain on the audio amplifier. And therefore, we must stay sometimes the pre-amplifier before LM386. I will show you the way to get the 74dB only with LM386. Please watch the circuit ! Rf is the feedback control resister. By chanbeing the Rf you can tune the gain of this circuit as follows.
Rf (ohm) | gain |
feedback
| dB |
3.3 | 74 |
10 | 70 |
33 | 54 |
105 | 44 |
820 | 34 |
Dear Sunamura-san, I like to read your web-site very much, and I repeated some of your constructions. I especially like your LM386 70 dB AF amplifier which I called =B3the Sunamura amplifier=B2 in our national Ham Magazine. Now, I have some news for you. The other day I found in our national ham magazine a new type of a rock stable VFO. They did not mention the first inventor, but I will try to find out who it was. It is a =8CColumbus= =B9 egg=B9 and it can substitute syntesizers. It uses a CERAMIC RESONATOR, and the frequency can be spread for about 100 kHz. I attach the electric diagram. The chief part s are the Ceramic Resonator CR and the variable capacitor C1. I used a standard CR for 3.579 kHz which is used as a clock in American digital devices. After a short warm-up, when you turn the capacitor C1 you can change the frequency for about 150 kHz - from 3440 to 3620 kHz. To cover the CW segnment of the 80 mteres band a variable capacitor of 140 pf is enough. And the frequency is rock stable. The capacitors C2 and C3 must have a capacity similar to the own capacity of the CR. In my case it was 600 pF. I also tried the ceramic filter for 10,7 MHz with three pins, but then I had to use 50 pF for C2 and C3, because that was the capacity of the filter. I used only two pins: the middle one and a side one - The frequency was between 10,9 and 11 MHz and the stability was very good. I also tried a 5,5 MHz filter, but it did not work well - it gave a frequency of 17 MHz with only 10 kHz of spread. I am sure that you will make use of this oscilator - with your tehcnical ingenuity. When I get some new CRs, I will make some more experiments. Meanwhile, I remain with best wishes, Bozidar Pasaric, 9A2HL, City of Rijeka, Croatia, Europe My E-mail: bpasaric@mac.com
Created by JF1OZL
Tuesday, July 20, 2010
One Transistor DSB Transmiter

One transistor TX (50MHz DSB)...1trtxph.gif
I challenged to make very simple transmitter. It is constructed with only one transistor. It makes DSB signal. It can make QSO with normal SSB station. ***
See fig 1! Carbon microphone modulates 50MHz CW signal. It produces a double sideband signal. It pass through the 50MHz band pass filter. It is radiated by the antenna. ***
See fig 2! Modulator is constructed by diode single balanced mixer. ***
See fig 3! This machine is transmitter. Therefore I must use another transceiver in order to receive the report from my QSO friends. ***
See the table! With this machine I made four QSO's with friends living 50Km distance from me.
Table1: result of one night local expedition by this transmitter. All QSO was mwde on 18 Dec 1993.
time(JST) | QTH of contact station | distance(km) | Report receiv | memo |
2121 | Kumagayacity | 67 | 41 | Not good signal.But recognized. |
2140 | Kawaguchicity | 57 | 34 | Only call sign was copied. |
2205 | kazocity | 47 | 45 | He could hear that I say " Carbon mic is used". |
2215 | Kakegawacity | 57 | 45 | Small beet was heard. Carbon mic was heard. |
Created By JF1OZL