[Boatanchors] JOHNSON 500 speech clipper mod?
garyskillicorn at hotmail.com
Mon Sep 26 17:35:41 EDT 2016
Not familiar with the 500 but being around from the tube days I recognize that the 6AL5 and 6C4 are entirely different, dual diode vs triode. Entirely different functions. For starters you sure correct tubes are in place?
Sent from my iPhone
> On Sep 26, 2016, at 5:26 PM, Gary Franklin <franklin6209 at att.net> wrote:
> I have a Johnson 500 which has developed a problem which I believe to be in the audio chain up to the 6B4G driver. The factory tube line up is: 12AX7 ( first and second audio amplifier), 6AL5 (audio peak clipper), 6AU6 (third audio amplifier), 6B4G (audio driver). My transmitter has been modified in the clipper stage. Instead of a 6AL5 it has a 6C4 .... Anyone know of this modification? could it be a WA1HLR mod?? I also have a small board mounted to the bottom of the chassis which has a SK 3021 NPN power transitor. Handles 300 vceo, 500 vcbo, 35 watt, 2amps in a TO-66 case. On the board is also (3) diodes and a 10K ohm 2 watt resistor. What mod might this be ??? may or may not be related to the 6C4.
> Boatanchors mailing list
> Boatanchors at puck.nether.net
More information about the Boatanchors