[600MRG] The need to transceive

[Glen Zook]

A 6 dB attenuator is a 4:1 on power.  If it were removed from the circuit, the amplifier would require 125 mW of drive.  It is where voltage is concerned that 6 dB is a 2:1 ratio.


http://nebula.wsimg.com/87fa72d0e2a5447f6496b4a6476ef1df?AccessKeyId=D1250C433DB440D6B60D&disposition=0&alloworigin=1


 
Glen, K9STH 
Website: http://k9sth.net

      From: Roger Graves <ve7vv at shaw.ca>
 To: John Harper <johnae5x at gmail.com> 
Cc: 600 meter group <600mrg at w7ekb.com>
 Sent: Thursday, November 2, 2017 1:08 PM
 Subject: Re: [600MRG] The need to transceive
   
John,

Which amp do you have? I have a 25W one that as supplied requires 500 mW drive, if the 6dB attenuator were removed it would be 250 mW, if the 1:1 input transformer were replaced with a stepup design (mosfets have high input Z on 630) I think it might get down to 25 mW. So you might not need an extra amp stage if your amp is similar.

The SoftRock RXTX uses a 2N2222 for the driver stage, you could look at the schematic of that for ideas and see my mod for a MF/LF transformer design. 
http://qsl.net/v/ve7vv//Files/RXTX LF-MF Modification.pdf