Topband: Topband Digest, Vol 168, Issue 3

[David Olean]

Hello Tree

     I tried calling you early on, with no luck in the ARRL 160 test. 
Possibly your noise was one reason you could not pick me out.  Later on, 
you called me while I was CQing, so all was good. I have a W8JI  DXE 
phasing box here, (NCC-1) and I use it to help cancel out some awful 
line noise to my west.  I suspect that there are many noise sources all 
contributing, but I am able to improve my S/N ratio quite well with the 
NCC-1.  I phase two beverages aimed at 220 and 260 degrees, and feed the 
output of the NCC-1 to my K3. At times I can get rid of about 10 dB of 
crud.  It isn't perfect, but it helps. Every day seems different, but it 
usually helps most of the time. I lose when the signal is the same 
heading as the noisy pole.

I am building another beverage and have hacked about 500 ft of brush 
thru the woods so far. I have much more to go as I am hoping to lay out 
1200 to 1500 ft of wire aimed at 290 degrees. I am hoping that it is out 
of the noise direction and will be quieter and work for stations in the 
far west. I have a JA wire aimed at 330 and it is quiet. I think that 
290 degrees is beverage #7 and my woods are getting pretty crowded with 
overhead wires. Only the west and SW wires are noisy.

Dave K1WHS

Lebanon, ME.


>     3. New use for Noise Canceling box (Tree)
> Message: 3
> Date: Sat, 3 Dec 2016 06:01:23 -0800
> From: Tree <tree at kkn.net>
> To: 160 <topband at contesting.com>
> Subject: Topband: New use for Noise Canceling box
> Message-ID:
> 	<CAKF9Hhaqb96NW4+914g-UO1pbyfNJYZs9FR10wWxjUuRuXwUkg at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> Last night - around 8 PM or so - this HUGE noise signal showed up on 160 -
> sweeping up the band slowly.  Probably a DC power supply with signals every
> 80 kHz or something.  But - it has some energy all over the ban - thus
> rasing my noise floor.  Sorry if I was an alligator last night.
>
> I put a Beverage up to the East just before the contest started - so I had
> two RX antennas - the other being a Hi-Z 4 square.  The Hi-Z said the noise
> signal was East - perhaps a bit stronger in the South direction than North
> - so call it just South of East.  The Beverage picked it up very well - so
> it agreed.  A feeble attempt at DFing last night was unsuccessful - but
> will be tried again if it stays on during the daytime.  It is still on this
> morning before Sunrise.
>
> The nasty part of the noise is about the same signal strength as most good
> signals coming in that are not local (looking at the band scope).  It has a
> 10 kHz or so wide peak.
>
> I was able to put the two RX antennas into a MFJ-1026 - with the output
> going to the RX input of my K3 - and adjusted the controls to null out the
> noise.  With a local signal - I have been able to obtain deep nulls and
> this proved to be true with this noise.  I was actually running guys on the
> East coast right in the middle of the worst part of the noise after doing
> this.
>
> This technique would likely be useful for those who have a similar noise
> situation - so I wanted to share.  You obviously don't need a beverage for
> the "noise" antenna - just something that is good at picking up the noise
> and perhaps nothing much else.  If you have a neighbor that has a noisy
> device - just put something that is close to their house.
>
> It's a battle out there to keep your noise sources under control.  I'll
> report back if I am successful in finding this one.
>
> 73 Tree N6TR / K7RAT
>
>