[AMRadio] Power Transformer as Mod Transformer (was: Seventy Fiver)

Bry Carling bcarling at cfl.rr.com
Thu Sep 24 05:50:08 EDT 2009

There is a great article on how to use power transformers like that - as 
a mod transformer - available on line for free - by Tim, WA1HLR

I hope it helps you - 


LEE, W0VT writes:

> I went to Lowe's this evening and picked up some oak lumber to build up some "Slat Board" 
> Transmitters. (They sell oak down to 1/4 inch thick to be used for the "slats". I plan to screw the 
> slats to the main oak end panels with brass screws and then stain and polyurethane the wood. I 
> plan to build up one chassis as a 6V6 oscillator with pi-net. Another with a 6AG7 with pi-net. 
> Then compair the output of the two plus check crystal current on both of them. Then I plan to 
> build up another one with a 6AG7 osc and 6L6 amp with pi-net and plug in coils. Then I plan to 
> build power supplies for these on slat board chassis and maybe use 5R4 rectifiers as I have some 
> of these around here. Then maybe a modulator for the 6AG7/6L6 rig. For a modulation 
> transformer I am thinking of trying a 70 volt or 25 volt line transformer or/and a power transformer 
> having it's core "restacked" in E and I configuration with a gap between the two. The projects 
> won't cost much and I think they will be great looking. I'll use broadcast band variable caps in the 
> pi networks. (Duals for loading and singles for the tank circuit.). Maybe use some rigid clear 
> plastic tubing over old tube sockets for the plug in coils. 
> Lee, w0vt 
>     ----- Original Message ----- 
>     From: Charlie , W5COV 
>     To: glowbugs at piobaire.mines.uidaho.edu 
>     Sent: Wednesday, September 23, 2009 9:04 PM 
>     Subject: GB> Seventy Fiver 
>     Group , the topic came up a while back with thoughts of building a 75 meter version 
>     of the Twoer etc. Heath line . 
>     Did it fall by the way , because of a lack of interest , or did anyone do any type of 
>     development on something like this ? 
>     I am ALWAYS looking for a glowbug project to build , that isn't real complex and 
>     won't break the bank. 
>     A transceiver to put on the air would be a nice project . I have a bench overflowing 
>     with homebrew transmitters , mostly CW . 
>     Being on a fixed income , I like projects that parts can be readily obtained for at 
>     cheap prices . 
>     With my medical problems , I lack the design ability , that I used to have . The 
>     medications and disease cause a technical medical term called "brain fog" . 
>     So I depend HEAVILY , almost exclusively ,on other peoples designs . 
>     So if you know of a simple transceiver design that glows and is AM , please point me 
>     to it . 
>     Thanks for allowing me to be a part of the best group I belong to !! 
>     73, 
>     Charlie , W5COV 

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