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Re: Linrad and the microwaves
- Subject: Re: Linrad and the microwaves
- Date: Fri, 24 Jan 2003 22:33:27 -0500
Hello Arie and Leif and All!
My use of Linrad on microwave has been most satisfactory but I am less
experienced with microwave work than Arie, and probably less demanding.
As you know, the main problems with microwave activity are not noise, as
they are on the lower bands, but rather:
(1) most often the station I am trying to find is quite a ways off
frequency (e.g. in the last contest, 10 KHz or more)
(2) he is also often very weak and
(3) chances are he drifts a lot.
The combination of (1) and (2) makes it hard to find him initially, with
a regular receiver. If he is 10 KHz off a soundcard waterfall hooked up
to the audio output of a conventional receiver just doesn't cut it, and
trying to initially detect him without a waterfall is very difficult.
With Linrad I can see 90 KHz and I always find him quickly. I think
this is a tremendous advantage on microwaves, and only Linrad has it so
The combination of (2) and (3) means that I want to use a narrow filter
to improve S/N, but his drifting makes that difficult as he doesn't want
to stay in the filter. With Linrad and its nice AFC the problem is solved.
I used Linrad in parallel with my FT1000 receiver for the last contest
(last weekend), as I had posted, and found that I could hear things just
as well on the FT1000MP with its 60 or 120 Hz DSP filter as with Linrad,
but I would have never found the way-off signals with the FT1000 were it
not for Linrad detecting them and allowing me to put the FT1000 right on
the frequency as displayed on the Linrad waterfall. My parameters for
Linrad may not have been optimal, but that had no practical
significance, as everyone who could hear me I worked, and I found
everyone's frequency very easily with Linrad.
I prefered this setup of Linrad in parallel to my previous setups of:
transverters and FT1000
transverters and Elecraft K2
transverters and DSP-10, and to
and I think to Linrad alone for this purpose.
Why the last statement? Well the great noise reduction capabilities of
Linrad are less important for this purpose because in my experience
noise isn't a problem as it is on the lower bands, and I am more 'used
to' the sound of the signal in the 1000MP DSP window than in a narrow
Linrad filter window, and find copying it 'easier' on the 1000MP as a
result. Would this be the case if I had grown up with Linrad? Probably
not, but that's a difficult psychoacoustic question ;)
On two meters the noise reduction of Linrad is so important that it wins
hands down in spite of this fact.
I apologize for not making any microwave "S" files during the contest.
Too bad this thread didn't occur 1 week ago. Then I would have ;)
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