Topband: A 160m Noise problem
donovanf at starpower.net
donovanf at starpower.net
Sat Mar 12 15:22:42 EST 2016
Its very suspicious that your RFI peaks right at 1820 kHz.
Can you hear the RFI on your transmitting antenna?
Can you hear the RFI on a portable receiver placed immediately
adjacent to your 4-square elements?
With your radio set to AM mode, does the RFI sound like
white noise, with no trace of an AC buzz sound? D oes the RFI
have any other observable characteristic on your panadapter
other than the spectral shape you already described?
As you mentioned, DC and RF are a serious problems if
water or any other contaminant is present in the connectors
or any other place where both RF and DC are present. Just to
be sure, suggest you disconnect the four Hi-Z elements and
reconnect them one at a time and observe to results on your
I had a very similar problem a few months ago that turned
to be a malfunctioning 10 watt Highway Information
Service transmitter on 1700 kHz.
----- Original Message -----
From: "Ed Stallman" <ed.n5dg at gmail.com>
To: topband at contesting.com
Sent: Saturday, March 12, 2016 8:04:37 PM
Subject: Topband: A 160m Noise problem
I would like to explain my noise issue to get opinions on search and Destroy
This noise is covering the 160m band only, 80m is good ! I'm using a
HI-Z receive 4 SQ and the NW direction is as quiet can be . All other
directions are noisy with the NE being the worst , SE almost as bad and
SW is somewhat OK. The noise starts at 1780 Khz and rises quickly to
its peak at 1820 Khz ! from there the noise levels off to 1880 Khz and
slowly drops to nothing at 2070 Khz ! Wish I could post a screen shot of
my panadapter for y'all to see, I'll be happy to send JPG file off list !
I was thinking maybe water in the RG6 and with the Bias T the Hi-Z uses,
this may be my problem but disconnecting and testing all the coax using
the 20meg scale ... all checks good ! I may replace the RG6 anyway but
thinking of running a beverage at 165 degrees and see if the noise is
still there . Was going to run the beverage anyway in hope of hearing
Heard Is .
At first I was thinking power line noise , I checked for noise using a
144Mhz AM receiver and 3 el yagi . I did find some noise to my NE but
gone today after the big rain . 160m noise is still with me!
Now I have parts ordered to build a small 160 loop . With that and my K3
I'll move to different locations and see how that works out .
Yes I have unplugged everything in the house and no switching supply's
that we leave plugged in . With computers off and using VFO I can see
the S meter rise and lower sweeping through the 160 band .
I've ask 2 of my neighbors to disconnect their elec fence with no joy .
I have to give my pasture a couple of days to dry out , then I'll run
the beverage and replace the RG6 on the RX 4 SQ with new flooded coax .
Oh and I also tried a BCB filter ..
Any Ideas what could cause the 160 only noise ?
Thanks Ed N5DG
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