YT1NT wrote:
>AGC DECAY can be kept at 5 dB/s with AGC HANG time at 0.30 - 1.00 seconds.
This minimizes AGC-induced interference with signals at noise level.
Very interesting Sinisa. I have not played with such high settings
of Hang and played with this on some very weak signals on Topband
this morning. Based on my limited use, it does seem to help. Could you
explain the theory behind this? I suppose it simply slows down the AGC
action to the point that it does not raise the noise level between CW
characters. BTW, I believe your two posts about AVC are the best new info
I have seen on this reflector in some time and recommend them to all:
http://dayton.akorn.net/pipermail/tentec/2004-February/042164.html
http://dayton.akorn.net/pipermail/tentec/2004-February/042183.html
I've printed them for my future reference.
Regarding ARRL's measurements of IMD and BDR with Preamp On and Off,
I asked KC1SX if perhaps the data had been transposed between the two
test conditions. He told me it had NOT and was as represented in the Swept
Graphs. I also cannot reconcile the better IMD with Preamp On since
ARRL measured 3-5 dB degradation in dynamic range when using the optional
500 Hz roofing filter. The 500/250 filter positions insert an additional
12 dB amplifier to offset the 8-pole filters' higher insertion loss and
this degrades IMD as expected, so why would the Preamp not do the same? I
agree that something seems inconsistent. When I feel like combing through
the schematics again, I want to take a look at the Preamp.
73, Bill W4ZV
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