[Heathkit] DX-40 Pwr Xfmr

[Garey Barrell]

Bill -

I think you have a shorted turn.

The two halves of a HV secondary will NOT have a similar resistance.  Both 'halves' have the same 
number of turn around the core, BUT with each layer added each 'turn' takes a little more wire.  So 
depending upon the number of layers required, there can be quite a difference in the length of the 
wire on the 'outer' half of the winding.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>


Bill Stewart wrote:
> Hi Lee,
> Shouldn't the ct to the outside legs divide the resistance and HV ac pretty much in half? In my case there is more than a few tenths of ohms or a few volts difference. I'm gonna pull the rest of the tubes and see if it still warms up...Tnx, Bill
>
> ----- Original Message -----
> From: "lee"<pulsarxp at embarqmail.com>
> To: "Bill Stewart"<cwopr at embarqmail.com>, "heathkit"<heathkit at mailman.qth.net>
> Sent: Monday, January 30, 2012 3:27:40 PM
> Subject: Re: [Heathkit] DX-40 Pwr Xfmr
>
> I assume you are saying it gets warm right away when the transformer has
> nothing hooked to the output winding.  You certainly will see a difference
> in resistance with both halves of that transformer.  That said if nothing is
> hooked to the transformer output and it gets warm quickly,  you have a
> transformer problem.
>
> Lee, w0vt
>
> -----Original Message-----
> From: Bill Stewart
> Sent: Monday, January 30, 2012 1:55 PM
> To: heathkit
> Subject: [Heathkit] DX-40 Pwr Xfmr
>
>
>
>
>
> Good afternoon:
>
> My trusted DX-40 is blowing its fuse. After some initial checks, I have
> disconnected the HV leads and made the following measurements: Total HV
> winding resistance: 312 ohms
>
> Outside-to-ct: 181ohms/344 vac....
>
> Outside-to-ct: 131 ohms/274 vac. The ac measurements are made with 60vac at
> the plug.
>
> The xfmr gets warm even tho the on time is short.
>
>
>
> Would ya say this resistance/ac voltage imbalance would indicate a tranny
> problem?
>
> Thanks, 73 de Bill K4JYS
>
>