[TMC] Thanks!

[Fred Telewski]

Hi Folks,

First of all, I would like to extend my sincere thanks to Al Duddles
(WA7GSK) for putting us on to this neat site for TMC equipment aficionados.

Next would be to thank all the folks who emailed me to say that they looked
at our site. I have emailed each of you separately to thank you and answer
any questions you proposed.

It occurred to me that we do not have a picture of our GPT 750 D2 on our
site. This unit is really cherry. I will have to take some pictures of this
and update the site.

I would like to say just a few words about philosophy (really, I will be
brief). Not only did TMC make some really forward-looking transmitters
employing the new power pentodes, but they used RF feedback as well, which
is why we took a fancy to the gear. We were always bothered by the high
levels of IMD on the ham bands and wanted our signals to be exceptionally
clean. It always bothered me to see perfectly good serviceable and
well-designed gear relegated to the scrap heap. It seemed to be an insult to
the folks who designed it and fabricated it. My philosophy, simply stated,
is that if the gear is still performance competitive, then it is worth
using. Our thanks to the folks at TMC for providing durable and performance
worthy gear, that amateur radio operators can still use, that exceeds the
performance of currently available amateur power amplifiers. Their legacy
lives on.

This concludes the philosophical statement.

Now, what can we contribute in the way of information to other TMC
transmitter collectors??

First as a matter of safety, On the GPT 750, I found out, by intimate
contact, that there was no bleeder resistor installed on the screen supply
for the 4-250A tubes. The documentation that I have also did not indicate
the installation of a bleeder resistor on this power supply. I elected to
install a 50k ohm bleeder as a very late after market modification.

If there is any interest, I can suggest ways to reduce the noise from the
blowers in the PAL 350/500 units as well as the PAL 1K unit.

We can also supply information on how to clean up really filthy gear. Our
first PAL 1K was positioned next to the exhaust of a diesel generator. You
cannot believe the amount of diesel soot this unit ingested. Today it looks
like just came from the factory. No ozone was destroyed in the process:).

There is also a capacitor failure mode on the PAL 1K that can cost you a
PL172 that we can share.

These are just some of the problems that we have encountered in restoring
our gear and would be willing to share solutions for.

Thanks,

Fred & Susan
WA7TZY/WB7BST