[Milsurplus] Re: LO radiation

[Mike Feher]

Lo re-radiation is indeed a significant receiver specification when the
receiver is used in surveillance applications. In the early 1980's I
worked as the Technical Assistant to the Director of receiver products
at E-systems. We designed numerous surveillance receivers for airborne
applications and special customers. We had to design special front ends
for them to minimize the LO leakage that came out of the mixer. Needed
amplifiers with very high reverse isolation. The reason now was the same
as back then. To minimize the receivers signature so that the
probability of detection or interception would be very low (LPI/LPD).
This is still a major concern for tactical radios, especially the one's
used by the special forces. Portable satellite terminals for the armed
forces also have to have a careful design to minimize the LPI and LPD as
well as what is known as the Circular Equivalent Vulnerability Radius
(CEVR in their transmit antenna patterns. 73 - Mike 

 
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-901-9193
 
 

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net
[mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Brad Latta
Sent: Tuesday, June 29, 2004 7:04 PM
To: milsurplus at mailman.qth.net
Subject: [Milsurplus] Re: LO radiation

Interesting subject,

                             I have just noted that Watkins Johnson, in
their 1986 catalogue for the WJ-9040 system (sigint), states the LO
radiation spec as -87dBm (into the antenna). I guess the military is
still
concerned about LO radiation!

 
Brad.