[RFI] The 160 meter spur

[Frank W3LPL]

Hi Rick

I've attached a photo of the four 237 foot towers used by 1660 kHz WWRU
and the four 237 foot towers used by the 1380 kHz WKDM.

The two directive antenna arrays share the same site at
350 Paterson Plank Rd, East Rutherford NJ

The 1940 kHz intruder is the third order intermod of 1380 and 1660 kHz

We should hear a distinct difference in 1940 kHz intermod near sunset
and sunrise when both stations change their antenna configurations and
WKDM switches from 5 kilowatts to 13 kilowatts

WKDM is licensed for 5 kilowatts daytime with 3 towers
and 13 kilowatts nighttime with four towers
They switch from three towers during the day to four towers at night

transition.fcc.gov/fcc-bin/amq?call=wkdm&arn=&state=&city=&freq=530&fre2=1700&type=0&facid=&class=&list=2&ThisTab=Results+to+This+Page%2FTab&dist=&dlat2=&mlat2=&slat2=&NS=N&dlon2=&mlon2=&slon2=&EW=W&size=9

WWRU is licensed for 10 kilowatts daytime and nighttime.
They have four 237 foot towers sharing the same site with WKDM's towers
They switch from two towers during the day to four towers at night.

https://transition.fcc.gov/fcc-bin/amq?call=wwru&arn=&state=&city=&freq=530&fre2=1700&type=0&facid=&class=&list=2&ThisTab=Results+to+This+Page%2FTab&dist=&dlat2=&mlat2=&slat2=&NS=N&dlon2=&mlon2=&slon2=&EW=W&size=9

The two independent co-located directive antenna arrays are directly across
the street from Meadowlands Racetrack and about 1/2 mile from New York Jets
and New York Football Giants stadium.

https://en.wikipedia.org/wiki/WWRU

https://en.wikipedia.org/wiki/WKDM

www.arcticpeak.com/radiopages/intermodulationproducts.htm

The attached photo clearly shows that the two stations have separate
directional antenna arrays than share the same property, a recipe for
intermod generation.  It could be as simple as corrosion in their
overlapping radial systems for the two directional antenna systems,
or the intermod could be generated inside the transmitters.

Perhaps only one of the eight towers is radiating the intermod...
You never know.

73
Frank
W3LPL