On Nov 1, 2009, at 11/1 7:27 AM, Jay wrote:
> Sort of like running a ST-8000, you have to know that the
> differences between AM and FM tu's are and also how the Regeneration
> works!
I've always wondered how many ST-8000 owners took advantage of the
receive regenerator. 50%? More?
Back in them days, I had written a program to talk to a pair of
Kantronics KAM+ (for two receiver operation). When I bought an
ST-8000, instead of changing the program to support the HAL, I kept
using the KAMs, but injected the ST-8000 regenerator into the KAM
input instead of injecting the radio AF directly into the KAM.
I had never transmitted through my ST-8000 either -- the KAM was
transmitting directly to the rig. That ST-8000 only had audio running
into it and regenerated audio running out of it (in addition to the
power cord).
I'd done the same thing with the Timewave 599zx. Like the ST-8000,
the 599zx also had both an analog AGC stage and a receive
regenerator. In addition, it has a test mode where it puts out a
string of RYRYRY into the regenerator output line; that made it really
easy to test if the regenerator path is working. The regenerator
bypass switch was a quick way to compare the demodulators in the 599zx
and the KAM.
The irony of it is that the KAM's tuning indicator was far superior to
the 599zx's tuning indicator. So I often would put the 599zx into
bypass just to use the KAM's tuning indicator, and then switch back to
use the 599zx's demodulator. Solved that problem later with a dual
cross ellipse software.
I held on to the KAMs for a long time, not because they copy worth a
darn, but because I was using them as backends to "real" modems and
never had to rewrite any software.
By the way, all that the AM/FM switch on a KAM does is to hard clip
the input stage to the discriminator so it looks like a discriminator
with a limiter :-).
73
Chen, W7AY
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