You can figure if 3 volts is 30% then 10 volts will be 100%. But make
sure you keep an 8 ohm load on the audio amp. The amp would be
operating way out in the nonlinear portion without 8 ohm load, the
result would be distortion. Figure your'e going to need 1.2 watts and
up to 12 watts of audio. Depending on how loud you want it on the Rx
end.

later,
ray KC8OJU



"bobinphx" wrote in message news:t_SWa.34180$Ne.22532@fed1read03...
Hi folks,
I've been lurking here for awhile and this is my first post.

I own a whole bunch of older tube radios. The majority of them are AM BC/SW.
I found a great site on the internet that broadcasts old radio programs
(http://www.yesterdayusa.com/) via the internet. Its great to listen to
while I answer emails etc, but when I am away from the PC, I cant listen to
it......So,,, I hooked up an older tube Eico 324 am signal generator to the
headphone jack of the PC and attached my SWL indoor random wire antenna (it
runs around the ceiling of the home office I have (about 12 feet on each of
the 4 sides, plus 6 feet of lead in)... Well,,, low and behold, I now have a
great little transmitter that transmits on BC and SW. It works great in all
rooms (the old radios are spread around the house).

Now to the question. What or how can I match the audio input to the input of
the signal generator?
The manual for the signal generator suggests a 70k ohm AF (audio freq)
input.
I am guessing that the PC headphone jack is 8 ohms, big mismatch.
What issues will this cause??????
The manual also has modulation notes that state "External AF voltage
required for 30% modulation at 1mc rf setting (1000 cps signal) aprox 3.0
volts" What the heck does that mean????


I am also unsure of how to match the antenna to the signal generator. The
manual does not state what the output could or should be.

Note that the generator does not run hot and has been recapped and
calibrated, to the best of my abilities!!!


I am a novice in terms of RF, but have been around TTL logic and have a good
general (read self taught) understanding of electronics. I am concerned
that long term mismatches may cause problems with the signal generator (I
know enough to be concerned, but not how to insure my fears are groundless,
for the issue is fixed. )

If anyone has any ideas they would be appreciated.

Thanks in advance
Bob in phx