[time-nuts] ext ref LNB Re: ADEV

[Mike Feher]

The military Ka band is 20.2 to 21.2 on receive and 30 to 31 on transmit.
Norsat of course has been making these for about 15 years, one of the first.
Back when I was working on Milstar 25 years ago, with the same receive
frequency, even the NF was classified. No, it does not make sense, but, that
was the way it was. I just had to deal with some ITAR related issues, where,
COTS equipment is being used, yet, it is now built for, or owned by the
military, and, while the hardware is not classified, it is restricted, even
as to who may work on it. I am just saying, do not hold your breath to see
them coming on the military surplus market. Regards- Mike

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-901-9193 cell


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of jimlux
Sent: Monday, November 15, 2010 10:16 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] ext ref LNB Re: ADEV

Mike Feher wrote:
> Well, that I do not know. The majority of Ku & Ka LNBs for home TV use are
> using free running DRO's. I have a bunch of them, and never ran across any
> locked ones, except for some of the ones used for internet service. My
real
> experience is what we use in military satcom terminals at Ku and Ka bands,
> with apertures from 0.6 to 9.2 meters, and they are all locked to an
> external 10 MHz reference. I doubt if you will see any major dumping of
> those. Especially now, because of strict ITAR. Even if one can buy it
> directly from the manufacturer, once the military has owned it, they will
> probably dispose of it in such a way that we will not see them on ebay.
> Regards - Mike


I doubt the LNB is export controlled.. It's unlikely to have an 
exotically low noise temperature, they're not cryogenic, they don't use 
components with dual-use, it's just part of a receiver.  If you go to 
the NORSAT website, for instance, they don't make much mention of export 
controls  (yeah, I'm sure the invoice/quote would have export 
boilerplate on it "the contents of this have not been reviewed... use, 
sale, distribution may require license...")

http://www.norsat.com/lnb/blog

And I note that the datasheet's pretty sketchy on the external reference 
LNBs.. They give phase noise as follows (for Ku band, 10.75 GHz LO):
-75dBc/Hz @ 1kHz
-85 @ 10k
-95 @ 100k

But they don't say whether that's added to the reference noise, or 
that's the "outside the loop" noise, or what..

What's interesting is that the Ka-band LNB (for 18-19 GHz, which is low 
Ka, to my thinking.. I think 30 when I think Ka).. the noise is actually 
lower
-65 @ 1k
-75 @ 10k
-95 @ 100k
-100 @ 1M

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.