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City: New Port Richey
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This is on a 40-190.
http://www.nostalgiaair.org/PagesByModel...013339.pdf
I believe someone wired this set wrong and I need to clarify the connection of the CT of the high voltage output from the power transformer. Originally when I got this set the CT was connected to chassis ground. My notes and pictures verify this. I don't know if this is why the rectifier was blown and the power transformer was fried but I don't believe this CT goes to ground in this set. I believe it's B-.
The CT should be isolated from ground and connected to part #60, 150 ohm 1 watt resistor, neg. side of the 12ufd filter cap and on from there. Is this statement correct?
Thanks,
Pepper
"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th
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Yes you are right if this is the correct schematic. Looks like an 'expert' was in there. Hope the power transformer isn't fried. Have a look at all the speaker, field coil, voltage dividers and add a fuse to the set.
Posts: 160
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Joined: Apr 2011
City: New Port Richey
State, Province, Country: Florida
Thanks! Someone was in here alright and the power supply that's on it now is not original. This was discussed in another post. It's high voltage output is 250-0-250 and the 84 rectifier was changed to a 5Y3. Even though the 5Y3 has a plate rating of 350-0-350 I'm told the 5Y3 should be fine and same for this transformer. All my filaments add up to 2 amps and this transformers 6.3Vac output is rated at 2.5 amps. Find out when she smokes.
Audio output transformer was fried. Got another on order. Everything else you mentioned looks okay but I'm overhauling the whole set anyway. Except for in a Zenith, I've never seen this much dried and cracked wiring. Maybe the set was dinked with so bad that all the wiring got hot, dried and cracked.
Johnny
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Major Frank Burns Mash 4077th
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Nah its a problem with all the rubber coated wiring from the late 30's and 40's. It's funny some color of wiring is fine and other colors are so bad just looking at them seems to make the coating fall off.
Posts: 160
Threads: 42
Joined: Apr 2011
City: New Port Richey
State, Province, Country: Florida
I need more clarification but this time on the connection of the + side of the 12ufd filter cap #61. The radio was altered and is running a 5Y3 rectifier instead of the 84. The 84 had the indirectly heated cathode but the 5Y3 doesn't have a cathode. I've looked at other radios that are running a 5Y3 and it looks like the + side of my 12ufd will connect to the field coil as shown on the schematic but also connect to one leg of the 5Y3 filament. Is this correct? Here is the NA copy of this 40-190.
http://www.nostalgiaair.org/PagesByModel...013339.pdf
Thanks,
Pepper
"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th
