Thread: RF amplifier
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Old December 5th 03, 07:01 AM
Richard Hosking
 
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I thought the Leader Sig Gens were free running and not very stable. Maybe
it is a new model.
If you simply want a CW TX, why not build the VFO as well?
There are plenty of designs around.
If you do want to use the RF gen , you could always follow it with a low
pass filter.

Richard


Sverre Holm wrote in message
...
My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I

need a
simple circuit to cover HF which will boost this up to 500mW. I would

like to
try out the signal generator as a low power CW transmitter.


I did something similar when I first was licenced in 2001, but I would not
recommend it now.

I used my Leader LSG-216 signal generator as a VFO followed by a 1 Watt
amplifier that I put together myself. It worked and I had several QSO's

with
it, but after several RST xx8 reports I found that the signal generator

had
hum modulation and some jitter. I have later learnt that this is almost
inherent in a synthesizer which covers a large frequency range. It has

very
large VCO gain: MHz/Volts - change in frequency per change in voltage in
order to cover the large frequency range. But this also makes it very
sensitive to noise in the control voltage.

As a signal generator, i.e. a tool for aligning circuits and so on, this

is
not a problem.


Sverre LA3ZA
www.qsl.net/la3za