Greetings to all,
An interesting thread. If you use a trapezoid display to tune your
linear amp, you will quickly see all the differences in tuning that are
being mentioned. The most obvious conclusion from these observation are:
1. Every voice require a different loading condition.
2. It is better, more linear, to err on the over-loaded side, than the.
under loaded side (if you just have to err).
3. If you tune with a carrier, loading will not be exact for voice.
About twenty-five years ago, Richard Measures published a great
paper on tuning linear amplifiers. His suggestion was to use a pulser with
a 3:1 ratio to approximate the "average" male voice. I found his unit, with
fixed 3:1 pulses, did not approximate my voice as close as I would like.
So, I modified his design to allow variable pulse timing, and, by
experimentation, found the ratio that best approximated my voice. Now, I
can use this pulser to tune any linear for my approximate voice, requiring
no touch-up tuning. It is inserting to note that Ameritron's tuning pulser
has variable pulse rate and speed.
Final conclusion: All this discussion about tuning is really
"much ado about nothing". With the addition of fully adjustable CW keyer in
nearly all transceivers, everyone has the ability to pulse tune a linear to
a very accurate degree (perhaps not perfect, but close enough). True, CW
will never match as closely to your voice as a properly adjusted pulser, but
will be so close that the point is hardly worth discussing. Unless you are
tuning with a trapezoid pattern, you will not be able to see the difference.
73 de Lon, K5JV
1110 Golden Bear Ln.
Kingwood, TX 77339
281-358-4207
281-358-4234 FAX
281-795-1335 CELL
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|