[Elecraft] 4M Question

Fred Jensen k6dgw at foothill.net
Mon May 19 19:53:37 EDT 2014


Overstatement seems to be the norm in everything these days. :-))

Not exactly "disallowed."  NorCal Hams have gotten along with the Air 
Force and their big radar for decades.  Their mission expanded, some 
mods to the radar, and, through the FCC, they asked for reductions in 
repeater field strength at the radar.  The mitigation requirements 
varied all over the place.  Some required just moving the 440 antenna to 
the other side of the tower.  Some -- Mt. Diablo for example [directly 
in front of the radar] -- were pretty severe, in the 45-50 dB range, 
which is pretty much "not on the air."

The requirement for the NCCRA/Cactus system on Bald Mt [K6SRA] was 35 dB 
which we were able to achieve by lowering the power about 7 dB and 
putting a directional antenna on the 440 with a 32 dB side null aimed at 
the radar.  Thanks to fortuitous geography, the forward gain compensates 
for the power decrease, and our coverage into the Lower Sacramento/Upper 
San Joaquin Valleys is still very good.  The null unfortunately passes 
right over my QTH, but from home with a small beam, I'm fine. :-)

The radar scan limit is a line about through PHX.  Our Squaw Peak system 
received no mitigation requirement.

Incidentally, to the best of my knowledge, there were no mitigation 
requirements issued for stations transmitting below 440 MHz.  Having had 
a tiny bit of experience with PAVE PAWS in a past life, I'm not surprised.

If 70 Mhz becomes an allocation, I'm pretty sure a 70 MHz xverter from 
Elecraft would be a good product.  Depending on the size of the 
allocation [if it happens], it might be interesting to not do repeaters 
there and leave it open for all the other things we do with our radios.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org

On 5/19/2014 4:07 PM, Rick WA6NHC wrote:

> 420-450 is
> disallowed over much of the state (150 miles circumference from
> Beale/PavePaws)...  Not a wasteland, just ham politics; often downright
> ugly.





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