Good Evening Everyone
Thank you for all the responses, some public, some private. Since some
content overlapped, I’ll post my answers to the group.
I replaced the 2K pot with a 1.2K resistor. No change.
I disconnected the feedline at the base of the Inverted-L (simulating a
relay). No change
.
The EWE is aimed directly at the vertical part of the inverted-L, about 25
to 30 feet away. The transformer end is towards the Inv-L. I didn’t
think about that when I put it up.
One radial passes the transformer end of the EWE by about 4 feet. No
radials pass under the EWE.
I took some pix of the bandscope / S-Meter tonight:
http://www.k3msb.com/temp/INVL_No_NB_NR.jpg
http://www.k3msb.com/temp/INVL_With_NB_NR.jpg
http://www.k3msb.com/temp/EWE.jpg
<http://www.k3msb.com/temp/EWE.jpg>
Here are some measurements (taken before the above photos were taken, so
there isn’t necessary any correlation to the measurements and the photos….
With the INV-L feedline disconnected:
EWE: S5 1.2 Khz filter NB no effect
S3-4 500 Hz filter NB no effect
S2-3 250 Hz filter NB no effect
With the INV-L feedline connected:
EWE: S5.5 1.2 Khz filter NB no effect
S4 500 Hz filter NB no effect
S1-2 250 Hz filter NB no effect
INV-L (NB/NR OFF)
S7-8 1.2 Khz filter
S5 500 Hz filter
S3-4 250 Hz filter
INV-L (NB/NR ON)
S2-3 1.2 Khz filter
S1-2 500 Hz filter
S1 250 Hz filter
The noise looks partially artificial. I’ve done the gig of popping all the
breakers in my house (except the one that powers the radios) with no effect
on the noise.
Using a portable radio, I swept the entire house and found nothing that
caused the noise issue go away. I didn’t turn off the cable modem (need
to keep the inmates happy….), but we got our cable modem in January, and
this problem pre-dates it.
Drove up an down my country road tonight with the car BC radio on as well
as the portable battery radio. The car radio didn’t pick up anything;
pretty quiet. The portable radio picked up hum, but it was everywhere I
went (including inside the house); when I plugged the portable radio into
the house mains, the hum went away.
I had my neighbor turn off his dusk/dawn light – no change in the noise.
The only thing I haven't yet checked is the matching transformer.
73 Mark K3MSB
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|
