[RFI] 160m spur

[Tom]

My recommendations:

1. Make sure it is not your receiver. If your receiver has a passive 
attenuator(resistor pad), go to a steady signal like WWV and switch it 
in, and see how much attenuation it supplies. Then dial in your 1940 kHz 
signal. Switch in the attenuation. If the signal drops the same level as 
you saw in the WWV test, the signal is coming via your antenna. If for 
example, your attenuation showed 10 DB attenuation at WWV, and you show 
a 20-30 drop at 1940, your receiver is into overload.

2. Lets say it is not your receiver. Where is the signal coming from?

     Possible choices:

     -It is produced at the broadcast transmitter site. Plenty of things 
to go wrong there. Been there.

     -It could be produced by some thing some place else, including the 
proverbial rusted fence.

     -it could be produced by something electronic in your house or 
neighborhood. These are always fun to trace down. Your receive location 
is definitely in the very strong field of the radio stations.

My guess is your will have to DF this. Please be very careful to not 
assume where the signal is coming from.

Of note, both AM stations are what is called a DA-2 directional. 
Different patterns day and night. WKDM changes power at night (actually 
goes up from 5 kw to 13 kw)

Does the level of the signal change at daylight or sunset? When it 
changes, it will be a sudden change. For the most part, the stations 
will go off the air for 1 second or so.


You have a bit of research to do. There is a lot of AM broadcast RF 
within a 2mile radius there in the Meadowlands.

Those two AM's, should have a calibrated field intensity meter, which 
could verify the level, and is also directional.

But asking for help is the key.


Tom Bosscher K8TB, retired from over 50 years of pushing the RF out on 
the broadcast bands.


p.s. side note. The first AM I worked for full time was on 1300 kHz. We 
had complaints of a S9 + signal on 3900 KHz (could have been kc/s back 
then!). My boss and I read a very weak 3rd harmonic at our own driveway 
at the transmitter site. In his driveway, we very much saw a very strong 
signal. On a hunch, I looked at his downspouts. All aluminum. I rattled 
them, and the signal went away. The fellow ham then asked about the S 
0.12 signal left on 1300. My boss said, "use it to calibrate your rig!".