BTW you can see my amplifier here:
http://home.centurytel.net/w7ry/Jims%20Amplifier%20Page.htm
73
Jim W7RY
----- Original Message -----
From: "Jim W7RY" <w7ry@arrl.net>
To: <amps@contesting.com>
Sent: Saturday, May 16, 2009 7:50 AM
Subject: Re: [Amps] filament transformers
> My homebrew 3CX800 amplifier filament transformer started with a 3 amp 12
> volt Radio Shack transformer. I did not have enough voltage so I simply
> added a few turns and increased the voltage for the two tubes.
>
> The transformer had lots of extra space on the windings and I did not even
> have to remove the laminations. I simply carefully scramble wound about 10
> more turns of #18 (could have been #20) enameled wire. Kept measuring the
> voltage until I had what I needed.
>
> The original windings were scramble wound too so no need for neatness with
> my added windings.
> 73
> Jim W7RY
>
>
>
> ----- Original Message -----
> From: "robert briggs" <vk3zl@bigpond.com>
> To: <amps@contesting.com>
> Sent: Saturday, May 16, 2009 6:03 AM
> Subject: [Amps] filament transformers
>
>
>> You are right Carl...I have always had the roving eye at hamfests and
>> disposal stores..I once brought 5 new Jennings vac variables, 5-500pf
>> for one dollar each at a disposals place...When I took them to the
>> counter and asked how much, the guy said $5 for the glass tubes....I
>> nearly ran all the way home...
>>
>> It is a shame that a lot of the old arts of home brew are being lost
>> these days..I know that many think that they don't have the ability but
>> the fact for me has been necessity as many components are just not
>> available in VK and too expensive to import..I still have a shed full of
>> "treasures" which I have collected over the years and I regularly search
>> through forgotten boxes of heaven knows what and old chassis looking for
>> "that" part" to complete a project..
>> I remember my first 80 meter transmitter crystal controlled...I pulled
>> apart many old FT43 crystals and re ground them on a piece of glass with
>> some bath cleaner, a painstaking job that many hams much older than me
>> will remember well..That was about the time I started re winding old
>> transformers and have been doing it since...You have to be inventive
>> some of the time but I guess that is what gives us the satisfaction when
>> you put something together and bring it to life...
>>
>> Ah well, I guess time moves on and things change....
>>
>> 73 all..Bob VK3ZL..
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
>
> --------------------------------------------------------------------------------
>
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 8.5.325 / Virus Database: 270.12.31/2116 - Release Date: 05/15/09
> 06:16:00
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
--------------------------------------------------------------------------------
No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.325 / Virus Database: 270.12.31/2116 - Release Date: 05/15/09
06:16:00
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|