[R-390] R390A alignment question

Tisha Hayes tisha.hayes at gmail.com
Tue Jan 12 13:52:43 EST 2010


Until I recently changed jobs I had access to the best Rohde Schwartz gear
for radio alignment and a nice lab to work from

Now I use my HP 3324A and an assortment of other HP devices to do "paying
myself" radio work. I was able to use the sweep generator and a Hameg
spectrum analyzer to build a roofing filter for the R-390A. The roofing
filter uses one of the torsion Collins filters with impedance matching
circuits on either side to improve the 3IP on the radio. I barely notice the
difference when listening with the radio and the improvements only show up
on test equipment.

The Dallas Langsford document on roofing filters was my inspiration. It is
really useful if you plan on going down this path.
-- 
Ms. Tisha Hayes

----------------
"I will not recant the truth. I am corn, not chaff; I will not be blown away
with the wind or burst by the flail. I will survive both."
-Walter Milne, 1558


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