08-08-2009, 10:33 PM
I found I needed a compressor to keep all my various CDs output levels the same at the input of my homebrew LPAM transmitter. By adding this simple compressor, allows me to run full 100% modulation from my LPAM xmitter, without having to make input adjustments from various CDs recorded output levels.
I found a nice-simple schematic online that works very well! Thought I would share it here. Most vintage radio restorers/techs will have the parts needed for this project onhand in your scrapboxes. The ac trans is not shown in the schematic, but ( adding it),..is simple to understand. I used a small ac trans with 117-125 v primary, and 150-ct-150 hv secondary, with a 6.3 volt tap for filaments supply.AC trans HV rect c.t. goes to chassis ground. Rectification is via (2) 1N-4007 diodes + to tubes plates via 1 connection point from trans h.v. leads. AC hum is filtered via a 100uf/ 350 v cap at B+ to chassis gnd.
As for the variable-resistors, I used a spare 1-M audio taper, & for the 25k, I used a good spare linear taper. It works well.
The 10uf electrolytic in the schematic , I used a spare 350v type. I used new carbon/comp 1/4 watt resistors throughout, and added a couple used 1/4 in female switchcraft connectors for hookup.
Heres the very simple 2-tube compressor schematic: ( many other good schemats at this site also!)
http://www.triodeel.com/comp1.jpg
I found a nice-simple schematic online that works very well! Thought I would share it here. Most vintage radio restorers/techs will have the parts needed for this project onhand in your scrapboxes. The ac trans is not shown in the schematic, but ( adding it),..is simple to understand. I used a small ac trans with 117-125 v primary, and 150-ct-150 hv secondary, with a 6.3 volt tap for filaments supply.AC trans HV rect c.t. goes to chassis ground. Rectification is via (2) 1N-4007 diodes + to tubes plates via 1 connection point from trans h.v. leads. AC hum is filtered via a 100uf/ 350 v cap at B+ to chassis gnd.
As for the variable-resistors, I used a spare 1-M audio taper, & for the 25k, I used a good spare linear taper. It works well.
The 10uf electrolytic in the schematic , I used a spare 350v type. I used new carbon/comp 1/4 watt resistors throughout, and added a couple used 1/4 in female switchcraft connectors for hookup.
Heres the very simple 2-tube compressor schematic: ( many other good schemats at this site also!)
http://www.triodeel.com/comp1.jpg
