Jose CO6EC sent us more information about homebrew rigs built in Cuba. The transmitter above is a thing of beauty. I am really glad that Jose has held on to it. Thanks Jose!
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Jose CO6EC writes:
This is another work from that time: an AM and CW transmitter of about 100W of power, with an on-board modulator. It was taken with some modifications from a Handbook from the 50s. Here goes: it was built with what we had on hand at that time, it still exists, I keep it as a relic of those years.
It used combined Soviet and American tubes in the RF sections: Soviet 6P9 and (2) 6146. The modulator used Soviet 12AX7, 12AUT and (2) 6P7. The 6P9 works as a crystal oscillator, and in case of using an external VFO it works as an amplifier and doubler or tripler to obtain outputs in the 160,80,40,20,15 and 10 Meter bands.
The VFO was also taken from a 1949 Handbook if I remember correctly, but I don't have any literature on that, as you can see in the photo it has 5 5u4c rectifier valves, VR150 voltage stabilizer, 6v6 output, another 6v6 as a separator and a 6 )I(4 (60I94?) Soviet, in the oscillator. The stability they achieved in those years is incredible, I could communicate with stations that were on LSB and if I didn't tell them that I was on AM they didn't notice.
As a receiver I used an old Soviet AM and CW receiver, used by the Aviation HF stations of the 40s, which no longer exists hihihihihi
I'll tell you how I tuned all that good ftuff: First I put the receiver in CW to beat the signal of the stations in SSB. After hearing them clearly, I removed the oscillator of the receiver and connected only the VFO of the Transmitter, and beat the signal with that of the receiver until I heard the other station clearly, then I put the transmitter to work and was ready to communicate.
There were many communications made with that station, even internationally on phone and CW.
Today everything is easier because with transceivers it is not necessary to go through all that work, but it is always good that those who did all this work know how radio was built and made.
73 Jose CO6EC
Posts
This handbook is a Editorial Arbo edition made in Argentina in the 1960-1970
ReplyDeleteThanks. I didn't know that there were Spanish language handbooks. 73 Bill
ReplyDeleteI thought the ARRL had one, but a check of the 1971 Handbook shows nothing. So I'm pretty sure it's Frank Jones/Bill Orr's Radio Handbook where I saw the notice.
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