Dear Pat, Les, LF,
I've been using the Icom PCR-1000 on LF for a few months, and it works
pretty well with my inverted-L antenna. It tunes down to 137 kHz OK so you
don't need a converter, but you do need a pre-amp/preselector to get the
best from the radio and suppress any birdies. I have been using the design
from G3YXM's webpage http://www.wireless.org.uk/circuits2.htm. (The one with
the two Toko coils)
The tuning is very stable and repeatable, the only slight drawback being
that you can't fit any additional narrow CW filters. This is fine for most
LF modes, ARGO etc, but if you need further filtering for audible CW, say,
you can follow it with an audio filter or use a filter program such as
Spectran.
Set the radio to 135.500 kHz USB to view the entire LF band using Spectran.
Dave G3WCB
IO91RM
-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Les Thompson
Sent: 12 March 2005 18:50
To: [email protected]
Subject: Re: LF: G3AQC
In article <[email protected]>, [email protected] writes
Hi Les,
I was interested to see you are using a PCR1000.
I too have one of these Rx's and have not so far considered it for LF
as I have others in use.
Have you compared it with anything else?
Apart from selectivity of loop are you using any other preselection?
Regards Pat g4gvw
Hello Pat
I only have the PCR1000 and an IC-725 that will cover the 137KHz
band. Between the two of them the PCR1000 is the more stable when
it's been on for about half an hour, it seems to produce fewer
birdies and there seems little difference in sensitivity.
I did try an LF converter that a friend lent me but it didn't
perform well with the loop, looked like an impedance mis-match
as it was reasonably perky when fed with an end fed wire.
No preselector or pre-amp, I only have the loop and when I want
to watch the whole 2.1KHz spectrum I have to dampen the Q with a
560K carbon resistor, I was surprised at how sharp the tuning is.
As Laurie said I really need to get something outside but I'm
still trying different configurations of loop at the moment
and it's easier to play with them indoors.
I've never done anything other than briefly listen on LF before
a few months ago and now know why I could never hear any activity
having done a bit of reading and also monitoring this group for
a short while. I got interested before Christmas when Walter
DJ2LF started his 440KHz tests and then moved lower to see what
I could hear.
Looks like I've still got a lot to learn.
73
--
Les G8ARF / G3VYZ
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