John,
I can't get your URL to bring anything up in my browser.
If your final Q is getting REAL hot upon keydown in a very short period of
time, I'm guessing you have some circuit issues there.
I had a similar problem with a little Tuna Tin transmitter I built a couple
years ago, my problem was my antenna was broken. It was not resonant on
7040, which was the crystal I had in the transmitter. It was way off.
After I replaced the final a couple of times, I broke out a SWR meter and
noticed the mismatch. A new dipole 15 minutes later did the trick.
I run a 40m 1/2 wave dipoe in the very top of my attic peak, so it's about
30 feet off the ground...which is pretty low for 40m anyway but I get out
pretty well.
If you do not subscribe to QRP-L I suggest you try there for some answers.
Some of the brightest low power folks in the world are there.
See:
http://qrp.lehigh.edu/lists/qrp-l/
73
"John Sandin" wrote in message
...
I am a new technician with code privileges. I built the following CW
transmitter for 40 meters:
http://cs.okanagan.bc.ca/ve7ouc/eng/...nsmitter2.html
It's a solid state 3-watter, based on an article in QST in June 1967.
I used a printed circuit board instead of wiring everything together
directly, as the QST article suggests. So, there are many wires
running from various parts mounted on the chassis to the circuit
board.
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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