[Boatanchors] CG-512

[Carl]

Thats what the link below is for. Its also explained in most Handbooks.

Carl
KM1H


----- Original Message ----- 
From: "Barrie Smith" <barrie at centric.net>
To: "Carl" <km1h at jeremy.mv.com>; <WA5CAB at cs.com>; 
<boatanchors at mailman.qth.net>
Sent: Sunday, January 11, 2009 8:03 PM
Subject: Re: [Boatanchors] CG-512


>
> ----- Original Message ----- 
> From: "Carl" <km1h at jeremy.mv.com>
> To: "Barrie Smith" <barrie at centric.net>; <WA5CAB at cs.com>; 
> <boatanchors at mailman.qth.net>
> Sent: Sunday, January 11, 2009 4:57 PM
> Subject: Re: [Boatanchors] CG-512
>
>
>> How did you magically find the full primary?
>
> He sent me a copy of an exchange on the AMFone mail list from 1998.
>
> I don't know who he is.  I tried to respond to his mail, but it came 
> back as undeliverable.
>>
>> You just have to love these people that enjoy sending private emails 
>> instead of actually contributing to the group knowledge.
>
> That is a problem.
>
> Anyway, if the resistance numbers I came up with don't make sense, 
> what about the voltage readings?
>
> 73, Barrie, W7ALW
>>
>> http://www.federalpacific.com/university/transbasics/chapter2.html
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message ----- 
>> From: "Barrie Smith" <barrie at centric.net>
>> To: <WA5CAB at cs.com>; <km1h at jeremy.mv.com>; 
>> <boatanchors at mailman.qth.net>
>> Sent: Sunday, January 11, 2009 1:18 PM
>> Subject: Re: [Boatanchors] CG-512
>>
>>
>> Okay, I had a 12 volt transformer on the bench, so I hooked it to one 
>> secondary winding.  I measured 13.3 volts in, and 5.23 out.
>>
>> This was using all of the primary, which an off-list person told me 
>> would be the 500 ohm input.
>>
>> I don't really know what to do with these numbers now.
>>
>> Any help appreciated.
>>
>> 73, Barrie, W7ALW
>> ----- Original Message ----- 
>>  From: WA5CAB at cs.com
>>  To: barrie at centric.net ; km1h at jeremy.mv.com ; 
>> boatanchors at mailman.qth.net
>>  Sent: Saturday, January 10, 2009 6:19 PM
>>  Subject: Re: [Boatanchors] CG-512
>>
>>
>>  Barrie,
>>
>>  I agree with Carl.  Assuming the primary impedance choices are 50, 
>> 200 and 500 as stated previously, I can't come up with a logical 
>> scenario that matches the resistance readings.  The secondary does. 
>> Or least it seems to.  Assuming the two windings have the same number 
>> of turns, the higher resistance of one could be explained by it being 
>> the outer winding.  It would have a longer mean turn length and 
>> therefore higher resistance.  The "F" markings probably stand for 
>> Filament.  If you were using it with a zero balance tube, you would 
>> connect one to each side of the modulator tube filaments and use a 
>> center tapped filament transformer.  But with the 100TH's you'll 
>> probably have to use fixed bias so tie the two together as you said 
>> earlier.
>>
>>  One way in which to reverse-engineer the primaries would be to 
>> attach a variac to one of the secondaries and measure the AC on the 
>> primaries. That will give you the turns ratios.  Square that for the 
>> impedance ratios and then see whether you can figure a combination 
>> that comes out in the ratio 50/200/500 or near to that.
>>
>>  In a message dated 1/10/2009 7:03:49 PM Central Standard Time, 
>> barrie at centric.net writes:
>>
>>    >About all I can find is that the specs are the same as the PA-512 
>> which
>>    >is the standard version of yours. Still no connection info. 
>> However that
>>    >model was around for several decades going back into the 30's.
>>    >
>>    >Perhaps Bunker of Doom has one catalog with info.  Or look in old
>>    >Handbooks, thats a fairly standard line to PP grids item.
>>    >
>>    >Those measurements make no sense.
>>    >
>>    >Carl
>>
>>    Carl:
>>
>>    I just checked the resistances again using a different meter. 
>> Same results.
>>
>>    Could I have a defective transformer?
>>
>>    73, Barrie, W7ALW
>>
>>
>>
>>  Robert & Susan Downs - Houston
>>  wa5cab dot com (Web Store)
>>  MVPA 9480
>>
>>
>
>
>