W9OY wrote:
>If you set the hang to zero it is my experience the
elements won't be lost to static induced gain
reduction in the AGC. If you set the hang to anything
except zero you run the risk of some crashes
activating the AGC enough when copying some weak
signals to blank character elements. This tends to
not be a problem on signals well above the noise. For
those signals I often use "slow", which I have set up
for 75M ssb ragchewing. For those strong signals slow
AGC (i.e. a long hang time and a shallow decay slope)
is like CW with FM like quieting.
Lee, I belive there are two different situations. The one
you are describing above is when there are high-level QRN
crashes from lightning storms. In this case you probably want
Decay fairly high (>50 dB/s) and Hang very low (0 or 0.04 max).
The other case is very weak noise-floor signals on a quiet band.
This requires completely different settings to prevent the AGC
from clipping weak signals along with the noise. This requires
Decay of 5 dB/s (can be slightly higher) and Hang of 0.30-1.0 s
as originally described by YT1NT at the bottom of page 4 here:
http://www.geocities.com/va3ttn/UsingOrionRX.pdf
"AGC DECAY can be kept at 5 dB/s (slightly faster in contests),
with AGC HANG time at 0.30 - 1.00 seconds."
I've done a lot of listening to the N2XE low-power beacon lately
and it is amazing to hear Orion extract the signal from noise
as you adjust Hang upwards. If you don't believe this, I would
suggest trying it on some very weak CW signals on a quiet band.
Fortunately the two cases above are mutually exclusive
since you will never hear anything close to noise-floor signals
on a band filled with big static crashes, but it is very important
to set the AGC differently for each case. I've pre-programmed
Slow for very weak signals in white noise and Fast for high
atmospheric QRN, in addition to being able to adjust Prog
for any situation.
There is nothing wrong with Orion's ability to copy weak
signals as some have claimed, but it does require knowledge
to know how to adjust AGC properly for all situations. There
is not a "one size fits all" solution.
73, Bill W4ZV
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