From FB group This Zenith Royal 500H radio has the extra 8th transistor for the RF amplifier, so it should have excellent sensitivity and be able to pick up those weak stations. Most of the problems with old radios are with the electrolytic capacitors, but the Zeniths all use the carbon composition resistors and they
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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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The beginning isn’t clear about how it looks. First, scroll to end and look at the photo. https://www.randombio.com/capacitor.html
From FB group Vintage Transistor Radios A thought occured. Do you think that Motorola may have had a lot of parts for tube sets and they decided to use them up by putting a transistor chassis in them? If you break down a radio into its assemblies and/or parts, which of them has the highest
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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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I spent too much time looking at the schematics and projects at this website. Lots of interesting things to download.https://www.qsl.net/va3iul/Homebrew_RF_Circuit_Design_Ideas/Homebrew_RF_Circuit_Design_Ideas.htm
From FB group Building Transistor Radios 2018-09-28 I see nothing wrong with using the ‘386 to directly drive the power output stage. It’s cheaper than a transformer. But I was thinking about how the current was flowing in the ‘386’s output transistors. Normally an electrolytic capacitor blocks any DC from flowing out of pin 5.
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