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  #16  
Old 05-19-2016, 10:29 PM
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jr_tech jr_tech is offline
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I think so also... looks to me like all 3 of the electrolytics in the 25Z6 negative supply are backwards.

jr
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  #17  
Old 05-19-2016, 10:34 PM
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rca2000 rca2000 is offline
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Not the FIRST time I have seen that in a diagram. IIRC...the diagram for my 48-700 had one or more electros wired BACKWARDS..for the HV supply...

Don't they PROOFREAD these diagrams--before they are published ? I would expect TODAY...maybe not..but back THEN..when people took MUCH more pride in what they did..they would have triple-checked for errors..

Last edited by rca2000; 05-19-2016 at 10:36 PM. Reason: More info.
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  #18  
Old 05-20-2016, 10:16 AM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by jr_tech View Post
I think so also... looks to me like all 3 of the electrolytics in the 25Z6 negative supply are backwards.

jr
The selenium rectifier circuit shown, seems to be drawn properly.
The power supply was the only repair that our set had in four years of use.
Emerson built a projector set, that used the same basic chassis, per Riders.
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  #19  
Old 12-30-2018, 06:28 PM
Tim Tress Tim Tress is offline
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I stumbled across this old post, and wanted to add some information. The first Emerson TV was the 545, which had a power transformer. The cheaper 571 had the hot chassis, with all of those 25Z6 rectifier tubes. The incoming AC is doubled to about 250, and is also rectified to give a negative 125 volts or so. This gives about 375 volts end to end, to supply the deflection circuits. For the next production of that chassis type, Emerson replaced the tube rectifiers with seleniums.

I wanted to add this information, in case anyone here gets to work on one of those old beasts. I have owned an early 571 for 40+ years!
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  #20  
Old 12-30-2018, 09:15 PM
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Kevin Kuehn Kevin Kuehn is offline
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I have a 638 console that uses the same chassis with the selenium rectifiers. It also has all those open holes were the tube rectifiers were in the previous version. I also have the 14" 698 model that stromberg6 mentions. It's been a 4 or 5 year work in progress but I'm very close to firing it up. I've nicknamed that chassis the spaghetti monster. It's just a wiring nightmare.
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  #21  
Old 01-04-2019, 01:45 PM
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Kamakiri Kamakiri is offline
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Quote:
Originally Posted by Kevin Kuehn View Post
I have a 638 console that uses the same chassis with the selenium rectifiers. It also has all those open holes were the tube rectifiers were in the previous version. I also have the 14" 698 model that stromberg6 mentions. It's been a 4 or 5 year work in progress but I'm very close to firing it up. I've nicknamed that chassis the spaghetti monster. It's just a wiring nightmare.
I haven't run across a '40s Emerson that wasn't!!
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