Several comments ....

When your output is a LOT different than you expect, likely there is
something wrong. Worse, there's a good chance that a lot of your energy is
being transmitted where you don't expect.

One thing that I found helpful on my first homebrew adventure was to model
any circuits that didn't seem to be quite right in PSpice. It's tedious,
but it helped me immensely in understanding what's going on.

Secondly, a 40 meter antenna 7 feet off the ground is going to radiate
pretty much straight up. That means that the only time any of your energy
will get back to the ground is when the flux is very high, something that is
happening less and less often. Worse, 40 meters is pretty noisy, and the
old novice segments really not all that heavily occupied, so not getting a
response right away isn't all that surprising.

If your output transistor is getting really hot you probably want to revisit
your heat sink. If you have, or can borrow, a scope, take a look around and
make sure that circuit is doing what you want. The heat could be telling
you that a lot of your energy is being spent in parasitics. Presuming you
have filtering after this transistor, that could be related to your low
output, as well.

If you have, or can borrow, a general coverage receiver, listen for your
transmitter on your fundamental, and on the harmonic frequencies, especially
the odd harmonics. You probably will be able to hear your transmitter on
21.330, but it should be a LOT weaker. If it isn't, you have a problem.

Finally, I would try to find someone local (line of sight, say 10-20 miles
if it's reasonably flat) and arrange a schedule. This won't take any
propagation and it will give you some idea that your transmitter is working.
Recognize that locals are often a lot weaker on 40 than stations more
distant, but if there are huge issues then perhaps this will uncover them.

Finally the chirp - get a fat wire from your power supply to the radio.
Also, make sure that the power path to the oscillator is very low
resistance. It doesn't take much voltage change to shift the oscillator
frequency, and there is a huge inrush of current on key down, so good old
E=IR tells you that with a big I it doesn't take much R!

Hope this helps...

...

"John Sandin" wrote in message
...

I'm getting very little output. After tuning the transmitter, per the
specs, and measuring the output using the method suggested by the
author of the web page, I figure I'm getting 1 watt or less. I am
running this into a dipole cut for 40 meters, which is 7 feet off the
ground. I'm using fundamental frequency HC6/U crystals for 7110 and
7125 kHz. I've been trying for 2 weeks, at all hours of the day and
night, and have had no indication that anyone hears me. I've called
CQ, and I've attempted to answer CQ's. Nothing, after about 100
tries.

I know it's impossible for any of you to know exactly what's wrong,
but I'd like to see what opinions I can glean here.

Is there any reason why I should use FT-243 crystals, as specified in
the article and on the website? I used HC6/U crystals because they
were easy to get.

One of the transistors (Q2) is supposed to be heat sinked. I have put
a large homemeade heat sink on this, using plenty of heat sink grease,
and it gets so hot I can barely touch it.

Also, the transmitter chirps a bit at the beginning of each
transmission, but settles down after a few strokes of the key.

Many thanks for any help you can give.


-John Sandin KC0QWE

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