[Heathkit] TX-1 Modifications

[Glen Zook]

The very first Heath "modification" was to change the VFO tube from a 6AU6 to a 6AH6.  This change was made after the first 100, or so, units were shipped.

The second Heath "modification" was to include the fan inside the final amplifier cage.  Heath had a modification kit to add the fan to those units that did not have the fan.

There was fairly popular non-Heath modification that removed the brace from the front panel to the top of the VFO housing and replacing it with a bracket that went all the way to the chassis.  This got rid of quite a bit of mechanical frequency instability.

If you are looking for a very easy modification that definitely improves the "scratchy Apache" modulation go to

http://k9sth.com/uploads/Not_so_scratchy_apache.pdf

The schematic is at

http://k9sth.com/uploads/audio_schematic_1.JPG

Glen, K9STH

Website:  http://k9sth.com


--- On Mon, 5/23/11, Rick <rickb at tx.rr.com> wrote:

I have run across no less than three circuit variations in the TX-1 I'm working on. Was there a later version of the transmitter? Most likely they are mods that have been made through the years, but I have no documentation to back that up. Can someone tell me of some of the more popular mods and/or where I might find info on them?