Topband: A 160m Noise problem

donovanf at donovanf at
Sat Mar 12 15:22:42 EST 2016

Hi Ed, 

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. 

Good luck 


----- Original Message -----

From: "Ed Stallman" <ed.n5dg at> 
To: topband at 
Sent: Saturday, March 12, 2016 8:04:37 PM 
Subject: Topband: A 160m Noise problem 

Hello Topbanders 

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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