[R-390] R-1247 Nasa Receiver info

[Richard W. Solomon]

I would think that the accuracy and stability of the First LO
(at Microwave Freq's) would be much worse than the low freq LO's
in the R-390. Unless they were phase-locked to a Cesium standard !!

Even then, Doppler shift would have made tuning a joy !! Just ask
anybody who is into EME.

73, Dick, W1KSZ


-----Original Message-----
>From: Bill Hawkins <bill at iaxs.net>
>Sent: Feb 25, 2010 11:19 PM
>To: r-390 at mailman.qth.net
>Subject: Re: [R-390] R-1247 Nasa Receiver info
>
>Group,
>
>I'm glad to know that the R-1247 functions as an R-390A by default.
>
>I bear the seller no ill will. NASA sets do not grow on trees.
>
>But I really wonder about the need for precise frequencies, when
>the R-390A is so well adapted to multichannel RTTY diversity 
>reception all by itself.
>
>Does anyone else know about the need for secondary conversion
>from microwave to precisely discover the Doppler shift from the
>microwave signal on the spacecraft?
>
>Would I really have needed the R-390A for SSB diversity comm in
>1965? Who would I be talking to? I can understand the military
>adopting precise frequencies to get closer to perfection, but
>did NASA need it for site communication?
>
>Thanks in advance,
>Bill Hawkins
>
>
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