In article ,
says...
(Fred McKenzie) wrote in message
Keeping the oscillator running and keying subsequent stages will usually
produce a more stable signal. However, it is not unusual for some of the
oscillator's signal to leak through and be radiated by the antenna. You can
probably imagine a CW tone that gets louder when keyed, but the pitch doesn't
change. When such a station is nearby, it is hard to discriminate between the
strength of the keyed and unkeyed signal. If you use this approach, you should
pay attention to keeping the oscillator from bleeding through. One method
might be to key all of the following stages, for example.

I had a rig in which I kept the oscillator running on key up. "VXO 6 watter"
from "QRP Classics". Great rig. The "backwave" never caused difficulty in
copying. I got about 5 W out (keydown) and about 15 milliwatts out (keyup!)
This provided some fun: If a station gave me a good report, I'd ask if they
could hear the REALLY QRP oscillator on key up. Many could!
73 Bill CU2JL
http://planeta.clix.pt/n2cqr

was there any shielding around the VXO or a terminator to keep the
leakage down?

mike c

Keeping the oscillator running and keying subsequent stages will usually
produce a more stable signal. However, it is not unusual for some of the
oscillator's signal to leak
The VFOs in all my old Txs stay on all the time. I use a simple RIT
circuit to move the VFO off freq on receive and key it with either
plus or minus depending on the way the rest of the Tx is keyed.
Works neet...
73 W7ZFB

Keeping the oscillator running and keying subsequent stages will usually
produce a more stable signal. However, it is not unusual for some of the
oscillator's signal to leak
The VFOs in all my old Txs stay on all the time. I use a simple RIT
circuit to move the VFO off freq on receive and key it with either
plus or minus depending on the way the rest of the Tx is keyed.
Works neet...
73 W7ZFB

On 13 Jul 2003 16:59:47 GMT, WA44NBI wrote:

You have good advice from Fred K4DLL.
I have built a lot of gear and would not even think of keying an oscillator.
73s
Bob WA4NBI

__________________________________________________ ______________

Sissy! :-)

The trick is to make the oscillator run at essentially the same power level
whether it is oscillating or not. This means class A operation and you key
the feedback loop instead of the oscillator itself. That way the tube or
transistor has the same dissipation at all times.

It's a bunch of work to design and probably not worth it, but it *can* be
done. (Just kidding about the sissy part).

--
73, Bill W7TI

On 13 Jul 2003 16:59:47 GMT, WA44NBI wrote:

You have good advice from Fred K4DLL.
I have built a lot of gear and would not even think of keying an oscillator.
73s
Bob WA4NBI

__________________________________________________ ______________

Sissy! :-)

The trick is to make the oscillator run at essentially the same power level
whether it is oscillating or not. This means class A operation and you key
the feedback loop instead of the oscillator itself. That way the tube or
transistor has the same dissipation at all times.

It's a bunch of work to design and probably not worth it, but it *can* be
done. (Just kidding about the sissy part).

--
73, Bill W7TI