Doug, thank you soo much for your email, you just fixed my transmitter.
Well, sort of.

As I tried to do what you had suggested I noticed that someone (I could
never have done such a thing) had connected the 18k resistor (which is
connected to grid # 2 on one end) on the wrong end of the choke.
I guess that choked it.

Now we don't just have oscillations, there is even a little bite to it.

I am relatively new to all this and I am just putting together the necessary
equipment. So a 50 resistor serves as my dummy load and a meter connected to
the dummy load indicates around 10 volts RMS. If I did my homework that
would indicate around 2 watt output. All this at B+ of 200v and an anode
current of about 35mA (I am running the transmitter off an adjustable bench
tube power supply at this point).

Does all this compare with the numbers you get with your transmitter??
I will need to build a power supply for the final version and would be
interested to know what you use for B+. In order to get 5 Watts I would have
to crank up the B+ quite a bit.

Actually I don't care at this point since I am still practicing for my code
exam, so I can't even use the transmitter right now.

How do you monitor your transmitting tone with a device like this.


Doug, thanks again, I am quite happy now


Uwe

KB1JOW





in article , Troglodite at
wrote on 3/11/04 14:26:

It oscillates nicely but does not have any power.
I know, it is not supposed to have much power but this one is weaker than
weak, the output couldn't drive any antenna.

I was wondering if there are AC-1 owners/builders around here who could
suggest a few things to try, who are knowlegable about this thing.

Did you do any voltage or current measurements? While I haven't played with a
real AC-1, I've built many similar 6V6 single tube transmitters. I have the
circuit for the AC-1, and it looks pretty similar to some I've built. First
thing to do is measure the B+ to the plate and screen. Next, open the plate
feed where it connects to the filter capacitor and insert a milliameter. With
the "load" capacitor at maximum, adjust the "tune" capacitor for minimum
current. Take a set of readings and get back to me.

Doug Moore KB9TMY (Formerly K6HWY)