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[Linrad] Re: WSE / Delta44 / Linad / MAP65 Windows local host setup
- Subject: [Linrad] Re: WSE / Delta44 / Linad / MAP65 Windows local host setup
- From: Joe Taylor <Princeton.EDU; joe@xxxxxxxxxxxxxxxx>
- Date: Mon, 27 Oct 2008 13:34:59 -0400
A brief follow-up to my message sent earlier today. I
downloaded your file 081026_2330.tf2 and used it to confirm
the two problems that I suggested you might have:
> 1. Your screen shot shows the signal level going into MAP65
> is rather too high, +20 dB. The main spectrum on the Linrad
> screen also shows the noise baseline around +45 dB, higher
> than desirable. It seems that you should reduce the noise
> level by about 20 dB.
> 2. Be sure to check the clocks on the computer running
> Linrad+MAP65 and the computer on which you were sending a
> test message into a dummy load. The clocks should agree to
> within a second or so.
I compiled a test version of MAP65 that divides the data
samples in your *.tf2 file by 10, to bring the signal level
into reasonable range. It also chops off the first 3
seconds of the file, thereby shifting the signal earlier by
3 seconds. The program then decodes your test signal
correctly, as shown in the screen dump at
The decoded message has DT = 2.3 s, so in your original file
it would have been 5.3 s. MAP65 searched over the range -2
to +5 s.
So, it seems that you are very close to having everything
-- 73, Joe, K1JT
-- 73, Joe, K1JT
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