[R-390] R-1247 Nasa Receiver info

[Bill Hawkins]

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