Topband: 1810 Revisited

WS6X ws6x at
Thu Feb 1 13:13:13 EST 2007

Paul, the engineer at KAVT here in Fresno, installed a filter in the KAVT
transmitter yesterday (01/31). After adjustment, he measured ". . . a very
significant decrease in the inter-modulation spur on 1810 kHz during day
power and day pattern. Testing during night power / pattern revealed an even
greater reduction in the magnitude of the spur."


My observations -- so far - concur that there has been a reduction in the
spur. Last evening I was copying the carrier at about an S5, with no
discernable modulation. After SR today, the carrier is an S8 with
equal-strength modulation components from both KXEX and KAVT. This is down
from a typical daytime signal of S9 + 20 dB.


Paul would like to hear from other topband observers in the west with before
and after comparative readings. I would suggest perhaps that you send your
reports off-reflector to me, and I will compile and forward them to Paul.




Jim - WS6X 


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