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[AMPS] Re: Filament Xfmr.

To: <amps@contesting.com>
Subject: [AMPS] Re: Filament Xfmr.
From: vk6apk@eon.net.au (Alek Petkovic)
Date: Mon, 04 Oct 1999 20:09:57 +0800
Hi Pat,
The answer to your question is Economics.

Running legal power with 4 tubes rather than 2, means you would probably
never need to buy replacement tubes. 4 tubes should give a lifetime of
service under those conditions.

73 de Alek.
VK6APK


At 07:02 PM 10/03/1999 -0700, Pat wrote:
>
>Hi Larry,
>
>Why would you want 4 x 3-500Zs?  Two will do max legal power nicely...
>
>73, DX, de 
>Pat, AA6EG/N6IJ; 
>aa6eg@hh.tmx.com;n6ij@hotmail.com
>599 DX Drive, Marina CA 93933
>See us on the web: www.polkinghorn.org/n6ij
>"The Contest Station from the Government"
>
>On Sun, 3 Oct 1999, Larry Molitor wrote:
>
>> 
>> At 11:39 AM 10/3/99 -0500, you wrote:
>> >
>> >About:
>> >
>> >"I am building an amp with four 3-500Z using low bands only (160 and
>> >80m).
>> >I do have two filament transformers, 5V/80A w/o a center tap on the
>> >secondary coil. The other one contains four coils with 5V/25A ea. coil
>> >also
>> >w/o any center taps on the secondary side."  (Etc.)
>> >
>> >How about connecting a small "audio" or "power supply" choke from each
>> >side of the secondary to "eventual" ground? Calculate the inductance
>> >value of them so that they will only allow a negligible (AC) current
>> >flow to ground while maintaining a balanced condition for all voltages
>> >involved in the circuits. I think reasonable sized, cheap chokes may be
>> >possible but must have low DC resistances. Maybe from junk box.
>> >
>> >73,    Roy         K6XK
>> 
>> I use a small filament transformer with a secondary center tap. Connect the
>> secondary across the big transformer secondary. Leave the primary open. Use
>> the small transformer secondary center tap for your cathode return.
>> 
>> 
>> 
>> 73,
>> 
>> Larry - W7IUV
>> w7iuv@arrl.net
>> http://www.axtek.com/w7iuv
>> Amp pix at http://207.108.137.61
>> 
>> 
>> 
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>
>
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