[TowerTalk] Replies to noise problems (long)

[David L. Thompson]

Here are the replies to the noise problems that I am having on 160 and 80
meters.  Seems there are three problems:

1.  Line noise
2.  intermod
3.  solar noise 

Here are the replies:

1.  From Jay K4OGG-----supported bt K4SB
My uneducated guess is that some of the new stuff put up following the
tornadoes is causing the problem -- probably one or more "new"
transformers.  I have wondered about that myself at my house, but no
similar problems for me thus far.  Ed K4SB agreed that this might be part of
my problem. 

2.  From Donnie KE4RNA-----
Here is the best reason for a high noise level on 80 and 160 right 
now: Solar-terrestrial conditions for the last 24 hours follow.
Solar activity was high. The geomagnetic field was at quiet to minor storm
levels.A major flare occurred at 0920 UT on 27 Apr

Looks like Donnie was correct..80 was much quieter the next day.  Even the
S4 noise on 40 I did not even list went away.

3.  From Fred, K1VR------
Fred had two ideas:

A. How good is house AC ground (third wire on incoming)?  May now be
floating.
B.. Is one of the downed antenna parts touching metal and creating a diode
to re-modulate noise?

4.  From  Ed K4SB  He agreed with Fred that my house ground might be bad.
and he offered his ICE filter to see about the intermod.

5.  From Bob Gay KA8CPM------
 Try turning UR TV set on and off & C if U can hear it anywhere
on the 75m band.  Mine makes all kinds of noise there from it's local
oscillator in the TV set.  Worth A try.  K4SB said some VCR;s have something
running that can put noises in the receiver.  I do notice during the CQ 160
tests that the band clears up after the TV's are turned off between 1 and
2PM local and those 3.57Mhz osc go to sleep.

SO FAR...........

I found the solar noise that blocked the VK on 3799 went away.

I cut all TV's and no change except on 160 where there is an S5 noise on
1823 that goes away when the Zenith (15 years old is off).

I check all antenna wires and did take the receiving loop off the 160
elevated radial (both are rubber covered either coax or #12 from Home
Depot)...no change.

I checked the ground and am not sure I have an adequate ground.  My main
power panel is tied to cold water copper pipe but its 46' to the main water
line from that point and my rig is attached to that same pipe system plus an
8' ground rod 11' away from the rig.  K4SB says I don;t have an established
ground as I read nothing from the common to ground.  I took a small AM radio
and as I put it near each AC plug near the rig and near the main panel I get
a high level of static on 1600Khz (lesser on 530Khz).  I do not hear the
same noise on upstairs sockets, where the power comes in, or across the
street at the underground xmtr. 

After finding this and I remember a problem I had 25 years ago...I feel the
intermod and the noise may be related.

What I plan to do next is:

1.  Put a ground at the AC entrance to the house with 8' ground rod to AC
common.

2.  Measure the resistance between AC common and my so called ground and the
hot water pipe (they are side by side 15' away from the radio table).
I am betting there is some resistance rather than short.

3.  I will probably put a second ground rod right outside my window (there
is a 4' cable co one there now) and make sure all my equipment is grounded.

4.  Probably early on in the testing I will cut all my power and run an AC
line to my next door neighbor;s and see what if any of the noises are still
there.  

Other points K4SB and another non Dx type ham brought up include making sure
none of my AC sockets are reverse wired or have loose grounds (Home depot
sells a circuit tester that quickly checks this...).  Replace wire guys with
phillystran, and maybe remove some of the antennas or move them to see if
the noise(s) change.

I will be recapping my beam (34XA) and cleaning up the antenna switch
(Heath) and doing other tower manintance, too.

Thanks and if you think of any other angles (I have not yet gotten to Jay's
comment of new lines etc with a mile or so) please shoot me an e-mail.  This
is not an absolute critical situation as I can work 40 to 10 and even 75/80.
Only 160 DX is messed up right now!

73, Dave K4JRB    


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