[CQ-Contest] Fringe reception

Joe Subich, K4IK k4ik at subich.com
Wed Mar 10 18:08:11 EST 2004


> From: Roger Parsons
> 
> As Yuri has said there is most unlikely to be anything
> wrong with the broadcast transmission. The problem is
> just that is is very, very strong at your location.
> Kind of similar to our neighbours' TVs not liking
> amateur transmissions! I do not think it is an FCC
> matter.

This is what is know as "blanketing interference" and there 
are rules against it (or were when I was actively working 
as a broadcast chief engineer).  Stations are (were?) required 
to minimize blanketing interference and take steps to remedy 
the problem on a case by case basis.  

I would look up the applicable rules (in CFR47) and then 
contact the station directly with a written complaint 
(copy to the FCC Field Operations Bureau ... whatever they're 
called today).

> It should not be too difficult to put a trap in to
> cure the TVI as there is a decent frequency
> separation. It may be very difficult indeed for you to
> receive a weak 90.1MHz signal in the presence of a
> strong 87.9MHz one. That really comes down to tbe
> strong signal performance of your fm receiver.
> Domestic equipment is most unlikely to be satisfactory
> under these conditions. Sorry.

Since Pete mentioned problems with TV channel 6 reception, 
trapping is essentially impossible ... 87.9 is actually 
INSIDE channel 6 (82-88 MHz).  I am sure that Pete will 
NEVER see channel 6 again other than when the FM station 
is off air. 

73, 

   ... Joe, K4IK 
 



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