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[Linrad] Re: MAP65 for SDR-IQ


I am deffinitely interested.  My eme system is H/V switchable in Rx 
and Tx independently, so I can tap off 2m in the shack to my DEMI 
144/28 + SDR-IQ whihc is connected to the computer via USB-2.0.  I 
have an earlier version of MAP-65 and winrad and JT-65 all on a Dell 
Vostro duo-core2 2.33 Gb computer (win-XP-Pro).

73, Ed
QRV with 2m-8877-600w

At 11:08 AM 2/13/2009, you wrote:

>Hello Moonbouncers,
>Many people have asked about a version of MAP65 that could
>be used with the SDR-IQ receiver.  I'm happy to report that
>an operational version of "MAP65-IQ" now exists.  It should
>be ready soon for testing by others.
>You'll recall that MAP65 works together with Linrad in a
>dual polarization or "stereo receive" system.  It takes
>advantage of many of Linrad's excellent features -- the
>waterfall displays, noise blanker, dual-channel coherent
>processing, etc. -- as its receiving "front end".  Partially
>processed data are sent from Linrad to MAP65, which searches
>for all JT65B signals in a 90 kHz bandwidth, measures the
>polarization angle of each one, and decodes them all.  The
>Linrad sample rate must be set to 96000 Hz.
>MAP65-IQ differs from the standard MAP65 in respects:
>1. MAP65-IQ is intended for use with single-polarization
>systems.  (Thus, no polarization matching can be done.)
>2. MAP65-IQ uses a slightly different sample rate, 95238.1
>Hz, in order to be compatible with the SDR-IQ hardware.
>MAP65-IQ appears to work very well.  In one test using the
>H-polarization (horizontal) data from 11 minutes of the 2006
>ARRL EME Contest, MAP65-IQ decodes 82 messages from 24
>different stations spread over the range 144.100 - 144.160
>MHz.  For comparison, the standard MAP65 decodes 127
>messages from 36 stations in the same 11 minutes of data,
>using both H and V polarizations.  For a rough sensitivity
>calibration, I was using a pair of 2MXP20 yagis when these
>data were recorded.
>These results are just what one would expect: the somewhat
>smaller number of messages decoded by MAP65-IQ is a result
>of its having no access to data in the "other" polarization.
>In order to make tests of MAP65-IQ you'll need a receiving
>setup with Linrad and an SDR-IQ, and you must be familiar
>with the use of JT65 in WSJT.  If you meet these
>requirements and would like to participate in early tests of
>MAP65-IQ, please send me an email with some details.
>         -- 73, Joe, K1JT

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