Topband: 1940 kHz intermod from WRRU and WKDM

[donroden at hiwaay.net]

> This is true ,    I contract for quiet a few AMs and FMs that can't 
> find anyone that want to be on 24/7 call.   There is this "thing" 
> called FCC Yearly NRSC Tests where an engineer with an analyzer checks 
> the spectrum and the station(s) must meet spectral purity ... ie: no 
> spurious emissions higher than XX db removed yy Kc from carrier.    It 
> sounds like one or both stations are producing an unwanted mixing 
> product.   "IF" they are co-located on or at the same site,  the 
> combiner "should" include traps that filter or reject each other's RF.
> It's possible that lightning / age / rats / snakes / birds have changed 
> the inductance of one of the traps.
> So, both of the stations may be unaware of the interference except on 
> the day of the NRSC test.
> 
> Don W4DNR
> 
> Jim VE&RF said :
> Problem is most AM / FM stations these days all contract out the work 
> for regular maintenance.