[Heathkit] TX-1 Modifications

[Rick]

Thanks, Glen and everyone who replied. This is a great starting point for me
to see if I can figure out what has been done to this old timer.
Rick

-----Original Message-----
From: Glen Zook [mailto:gzook at yahoo.com] 
Sent: Monday, May 23, 2011 5:15 PM
To: heathkit at mailman.qth.net; Rick
Subject: Re: [Heathkit] TX-1 Modifications

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