A trio of Hacker Democrats
The Democrat RP34 is an AM only radio dating from around 1966 and uses two PP9 batteries to provide an 18 volt supply. All three radios needed attention to get them to work properly again.
Number 1. Appeared to work but clicked and went off at the slightest tap anywhere on the chassis. Of course this turned out to be the usual AF117 transistor troubles and replacing T2 on the I.F. panel restored normal operation. I used a germanium AF178 as I recently bought some for a bargain price from an Ebay seller based in Europe. They also look nice in a vintage radio.
Number 2. No sound although the audio amp circuit was working. This time all three AF117s on the I.F. panel had shorts between electrodes. The mixer oscillator transistor, which is on the wavechange switch panel, was OK.
Number 3. I had repaired this one a few months earlier, replacing T3 and T4 on the I.F. panel with silicone BC557s (all I had at the time) and had been happy with the overall performance. However compared to the other two Democrats the RF sensitivity was a little down and there was an unwanted "interstation mute" effect when tuning. Weak stations had distorted sound. Replacing T3 with an AF178 brought things back to normal. The radio was quite happy with a BC557 for T4 though.
People have their own ideas on how to deal with the AF117 transistor problem and there are many posts about this on the Forum.
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Regards
Martin
Last edited by martin.m; 3rd May 2019 at 9:50 pm.
Reason: Typo
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