PT Question

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Dmichel1984
Junior tube assistant
Posts: 17
(3/11/04 4:53 pm)
 PT Question
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 I have three old PT's I got from OldRadioParts.com, but one of the PT's only has 3 leads on the secondary, labeled as Red(HV), Red/Yellow(CT), Green(6.3V Heater)

Is something wrong, or how do I use this tranny?
 
wayneosdias
Senior tube assistant
Posts: 255
(3/11/04 5:41 pm)
 Re: PT Question
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 how many on the 1mary side?

wayne
 
Dmichel1984
Junior tube assistant
Posts: 18
(3/11/04 10:58 pm)
 two
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 there are 2 leads on the primary side
 
wayneosdias
Senior tube assistant
Posts: 256
(3/12/04 12:32 am)
 Re: two
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 dunno, do the 2ary's short between each other? have you tried powering it up and measureing the 2ary's? basically i dont know.

GL
wayne
 
Dmichel1984
Junior tube assistant
Posts: 20
(3/12/04 12:56 am)
 not yet, unsure...
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 I've not yet powered it up, because I wasn't sure were to measure for AC(don't you need 2 sources? to Alternate?) BTW, The Red/Yellow is labled Common, not CT...
 
wayneosdias
Senior tube assistant
Posts: 257
(3/12/04 1:27 am)
 Re: not yet, unsure...
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 try testing continuity of the 2's, sound like its a single winding w/a center tap, dont really get the color designation. not sure what you mean by 2 sources of alternating ac, assuming its a 120v main youd just plug it in, again assuming your in the states.

wayne
 
wayneosdias
Senior tube assistant
Posts: 258
(3/12/04 1:30 am)
 Re: not yet, unsure...
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 err, i mean 110v mains

wayne
 
Tiny Daddy
I will work on all amps
Posts: 545
(3/12/04 9:13 am)
 Re: PT Question
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 Try powering one of the windings with a low voltage such as 6.3 volts and measure voltages on the other windings.
 
Dmichel1984
Junior tube assistant
Posts: 21
(3/12/04 3:04 pm)
 ok
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 i know how to hook up the primarys, but i thought i would need 2 HV leads and 2 6V leads/...
 
Dmichel1984
Junior tube assistant
Posts: 22
(3/12/04 4:00 pm)
 Re: ok
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 I guess only 1 HV lead is OK, using half wave rectifier anyways. but I thought I needed 2 6.3V heater leads???, how do i wire the filaments w/ only 1 6V source??
 
Tiny Daddy
I will work on all amps
Posts: 554
(3/12/04 4:33 pm)
 Re: ok
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 Just guessing, I would ground the Red/Yellow(CT) and expect to measure the Red(HV) and Green(6.3V) with respect to ground. Then use a half-wave rectifier or full wave doubler on the HV.
 
Dmichel1984
Junior tube assistant
Posts: 23
(3/12/04 9:28 pm)
 Re: ok
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 so to heat a 6V heater, i would run the 6V to all my tubes and ground? the other side of the filaments? or??
 
Tiny Daddy
I will work on all amps
Posts: 556
(3/12/04 10:29 pm)
 Re: ok
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 Yes one side of the filament to 6V, the other side to ground. But check out the transformer first and make sure it is doing what you expect. And don't just drop grounds to chassis everywhere. Connect the filaments with twisted pair in the usual manner and run a ground wire back to the power supply ground.
 
Dmichel1984
Junior tube assistant
Posts: 25
(3/12/04 10:40 pm)
 Re: ok
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 thanks! i wasn't sure if this one was going to work, and I like it better than the others because it is painted black...
 
 
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