Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on March 16, 2014, 02:41:43 pm

Title: Recovered transformer 0-310v (200-250mA ???) - 7v 2A - Any idea ???
Post by: kagliostro on March 16, 2014, 02:41:43 pm

From a small Tube Linear Amplifier for RF I recovered a transformer (about 100-120W) with 0-310v and 7v 2A

I consider the 7v as a 6.3v winding, if it diden't drop by himself during function, a resistor will do the job

in the original schematic the 0-310v winding was used with a voltage doubler, but considering to use it with

a full bridge I think I'll obtain about ~430v for tube plates (I think that there are ~200mA disposable)

Any idea about the reuse of this transformer ?

Thanks

K

Title: Re: Recovered transformer 0-310v (200-250mA ???) - 7v 2A - Any idea ???
Post by: sluckey on March 16, 2014, 03:03:23 pm

Heavy duty B+ but light weight filaments. Probably perfect for a one or two tube RF linear amp.     :icon_biggrin:

Title: Re: Recovered transformer 0-310v (200-250mA ???) - 7v 2A - Any idea ???
Post by: kagliostro on March 16, 2014, 04:56:18 pm

:icon_biggrin: Yes :icon_biggrin:

but something around 18W audio with which tubes ??

Ciao Steve  :smiley:

Franco

Title: Re: Recovered transformer 0-310v (200-250mA ???) - 7v 2A - Any idea ???
Post by: sluckey on March 17, 2014, 09:39:50 am

You may consider Mark Huss's Plexi 6V6. Three 12AX7s and two 6V6s. Filament current is 1.8A and the 6V6s can take the B+.

     http://mhuss.com/Plexi6V6/index.html (http://mhuss.com/Plexi6V6/index.html)

Title: Re: Recovered transformer 0-310v (200-250mA ???) - 7v 2A - Any idea ???
Post by: kagliostro on March 17, 2014, 04:48:42 pm

443v at node A !

That seems really perfect  :thumbsup:

Grazie Steve

Franco

Title: Re: Recovered transformer 0-310v (200-250mA ???) - 7v 2A - Any idea ???
Post by: kagliostro on March 19, 2014, 12:03:45 pm

My plan failed

I received the transformer today

and it hasn't the specs I told

I referred the 310v (with doubler) and 7v to a model of Linear amplifier that used 1 x 6KD6 tube

but the donor linear of the transformer uses the same 1 x 6KD6 tube

but a 500v (no doubler) winding instead of 310v

(http://www.cbtricks.com/Amp/cte_international/speedy_rf100/graphics/cte_speedy_rf100_sch.gif)

So I think this thing will be usable only if I rewind it  :embarrassed:

K

Title: Re: Recovered transformer 0-310v (200-250mA ???) - 7v 2A - Any idea ???
Post by: kagliostro on March 19, 2014, 03:54:40 pm

Thanks for the idea

solution may be also that way

Franco