|
Laurie,
From among my own receivers, I find
that the Cubic 3280 is a very good DSP receiver AND you can shut the AGC
off.
For non-DSP, the newer RACALs such as the 6830 work
great and have switchable AGC.
An SLM such as the 3586 is a good choice if all you
don't need an AM detector.
I agree with the comments on the R75 and AOR 7030-
but both benefit from adding the cw filters.
If price is no object QST claims that the Icom
R-9500 is one of the best ever in terms of strong signal handling (though I
can't confirm this from personal experience yet).
73 Warren K2ORS
----- Original Message -----
Sent: Friday, January 11, 2008 1:45
PM
Subject: LF: LF Receiver
I have for a long time used a Racal 1792 reciever for QRSS
modes on LF.
This receiver failed recently,and I have been looking for a
replacement receiver.
This search reveals a problem most modern receivers
use DSP techniques
for filtering and the AGC is derived from the filtered
signal. None of the receivers
I have looked at have an AGC OFF
facility.This means that if one of these receivers
is used with ARGO or
similar FFT programs a strong signal within the pass band
will desensitise
the Rx. It seems quite possible that a weak signal could quite
disapear. It
also appears that some AGC is applied before the digital filter so that
signals within the roofing filters bandwith will also produce
de-sensitisation, and this
could be as much as 15kHz away from the tune
freq.
Any ideas on receivers not using DSP filtering ?
Or do I look for
another R1792
73 Laurie
G3AQC
| 