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#1
04-28-2021, 05:02 PM
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Zenith Royal B47 schematic
Hi all. I need a schematic for a Zenith Royal B47 schematic.
Not going to put down $7.95 plus shipping for a copy of the manual as I see in my Google searches. Amp needs work as it uses a 2SC735,2SA562 and a 2SB482 as driver configuration.. Has anybody seen this configuration.. Add more.I got it from the shop years ago.I believe that somebody plugged a wall wart into the earphone jack or wrong polarity at the tip of the regular phone jack style power plugin.. As I found that both output transistors are blown out.The tuner sect works fine. Thanks in advance . Last edited by centralradio; 04-28-2021 at 09:10 PM. 
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#3
04-28-2021, 09:03 PM
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Did you read the post first ..Thanks anyway..
Quote:
Last edited by centralradio; 04-28-2021 at 09:11 PM.
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#4
04-29-2021, 05:59 PM
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Quote:
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#5
04-30-2021, 10:39 AM
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No problem nasadowsk.Sorry if I offend you..It happens to all of us..I notice I did the same thing by posting this radio in the tube radio section..
If it was a prewar tube radio .It would be fixed by now.. Have a nice weekend.. BTW ..... NOTE to Mods.Can you move this topic into the transistor radio section please..My bad.It should of gone there..Sorry about that. Quote:
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#6
04-30-2021, 03:43 PM
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Its in Sams TSM145. I dont have it. TSM were separate from the regular
Sams series & not many got them. They cover quite a few small radios in one volume. Sams also had other separate series for specialties such as MHF ( modular HiFi ) , AR ( auto radio ) CB (CB) etc. The output design is quite typical. Fix almost always is change all three transistors, check low ohm resistors in output & change the speaker coupling cap ( usually between 220mfd & 470mfd). When you have audio outs & drivers DC coupled shot gunning is best. 73 Zeno  LFOD !
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#7
04-30-2021, 04:10 PM
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Hi Zeno .Thanks for the Sams lookup and tips. .I have a handful of the TSMs here somewhere..The output cap is a 220uf BTW..
Do you have a equiv schematic somewhere I can go by for now.. Quote:
Last edited by centralradio; 04-30-2021 at 04:14 PM.
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#8
04-30-2021, 04:16 PM
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Quick lookup for the Sams date is January 1, 1973.So it probably came out late 1972 just in time for Christmas 1972..
nasadowsk was asking for the date info.
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#9
05-01-2021, 05:13 PM
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90 hits . Anybody can help me with this radio.Any takers..
Must be a rare radio..Not much online about it. Dont see anything on Radio museum unless I looked wrong. Need a schematic with a similar design with 2SC735,2SA562 and a 2SB482 as driver configuration.Also with two diodes after the driver..More likely need transistor pinouts in circuit to see what is up.. Looks like the guys at the shop where I got this from worked on it.I want to see if the 3 transistors were installed right.I may did an error the other day putting some in wrong too.. With brain fog. Been years away dealing with these non transformer amps.. I rather deal with push and pull amp circuits.. Last edited by centralradio; 05-01-2021 at 05:39 PM.
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#10
05-02-2021, 08:07 PM
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Had a chat with a friend earlier today online.He is a radio restorer for years . He does not have a copy of the Zenith manual or the Sams TSM manual.
He suggest to put an infamous LM386 chip on a small perf board small enough to fit in the case with out altering original parts and case.Its a quick cheat fix for now until some schematics or service manual shows up later on.Then fix it the right way when the manuals come in hand..
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Linear Mode
