Also to FB group Vintage Transistor Radios I finally drew the line and said I’m finished fiddling with this Zenith Royal 200 and put it back together. I got it without knobs or handle, and with all the transistors missing. It’s not pretty, and the speaker cone is warped and sounds bad. This is the
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Continued from post 2020-01-15 I dug through my drawers and boxes of transistors and found a bunch of MPSA56 PNP general purpose on tape, and put them into the LO and mixer. I think they helped slightly – they are lower minimum fT than the 2N3906s. I adjusted – optimized – the trimpots I had
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I’m thinking of pulling up the end of the 100 ohm and looping the lead a few times through the ferrite bead. If that still doesn’t stop the ringing, I’m thinking about replacing the bead with an RF choke. Every time the ringing is reduced the reception gets better. I checked to see if I
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This photo is a detector diode that was broken during replacing the electrolytic capacitors. The lead on the top was twisted, apparently putting stress on the glass package. I replaced it with a 1N270 germanium diode. comment from fb group Vintage Transistor Radios Did you notice that the leads are magnetic? They stick to the
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I posted this a few days ago.https://m.facebook.com/groups/606087512820068?view=permalink&id=2638214152940717 Now I’ve replaced the capacitors in another one very similar, a DE LUXE. It’s not quite as complete and in as good a shape as the Encore. What surprised me was that some of the electrolytic capacitors were bad (measured open) and the symptom was no sound whatsoever
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From FB group Vintage Transistor Radios There are really only two types of germanium transistors in older radios. One is for the RF and IF stages and has low collector to base capacitance. The other is audio and can handle a few hundred milliwatts. I recently replaced the germanium audio transistors with silicon, with change
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From FB group Hobby Electronics, 2018-09-01 I faced this dilemma before. I’ve repaired power supplies where the transistor failed because it was not held tightly to the heat sink because of a nylon screw that got hot. I used a steel screw and a fiber washer, and heat shrink tubing over the threads to insulate.
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Happy New Year! I replied to a comment by George Glavas on FB group Vintage Transistor Radios George Glavas I’ve never read any documents to back up your claim that “…germanium transistors lose gain as they age.” I think that people believe this because old equipment has lost gain. But all of the problems I’ve
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I tried to to post this to the FB group Vintage Transistor Radios, but the FB app crashed and I lost several lines of my typing. Makes me angry! The radio was not making any sound. I removed the chassis from the case. I found the ‘battery saver’ slide switch had been forced apart. I
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I was the only bidder on a lot of three radios, one of them is an Olympic model 860 AM transistor radio. This radio uses four AA cells for a total of 6 volts DC. Overall the radio is in good condition – no chips or cracks. I powered it up and if I turned
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