[IRCA] coax system update

[mwdxer@xxxxxxxxx (Patrick Martin)]

Greetings,

I thought I would pass on the latest on the coax issue. After I replaced
the matching transformer boxes with F Fittings, and changed two over to
metal boxes, It was quite an improvement. I think getting rid of the
pigtails (banana plugs) on the end of the coax made the biggest
difference. The discussion of plastic vs metal boxes,I do see a
difference using a metal box for the beverage, but for the EWE antennas
I see little difference. I have no idea why either.
   I got some termination plugs from Radio Shack to check the leakage of
the coax. Remember I was getting S9 on CBU-690 at one time. Well, the
results were much better. I was getting CBU at threshold and the locals
at S7-S9. 
  John Bryant loaned me a "choke box" he had made up to get rid of the
"stray signals". I installed that between the R8 and the coax, plugged
it right on the back of the receiver. Since the shield side is
"floating", there is no longer a direct ground between the coax and the
receiver. But with the choke in series, I did the test again. My locals
went from S-7  - S-9 down to S1 and below! I was quite surprised. Only a
threshold on the 1650 TIS in Astoria. Wow what a difference. I found
several channels there was no longer a dominant station but a mumble
jumble, especially at night. CX aren't even all that great either with
the A&K elevated. I need to buld a couple of those boxes, and I thank
John was the loan of the choke box. Much appreciated! 
   OK, a suggestion was to attach a ground from a separate ground rod to
the shield of the coax coming to the choke box. I think with all of the
grounding I have, it is finding a ground somewhere through the system to
work so well, but a solid ground would be better. I thought so to, but I
have run into a problem. I disconnected the antenna once again from the
matching transformer box and put the termination plug in. I then
rechecked the S Meter readings running the coax through the choke box.
As before the S1 signals. The lower frequencies being weaker. Like KSWB
840 is quite weak, and KAST 1370 is a little stronger. I installed a new
10 foot ground rod a couple weeks back, so I disconnected that rod from
the receiver and left the 4 foor one. I thought the 10 foot rod would
work better. The two rods are dependant from each other. OK, I had the
S1 on KSWB 840, I touched the ground wire to the coax shield and instead
of improving the setup, the S Meter went to S9! The ground is working
more like an antenna instead of a ground. This 10 foot rod sits in wet
soil too. Quite wet. What is going on here? So apparently the ground rod
to the coax shield is not going to work. The system is better floating.
I have no idea why it reacts that way, but it does. 
The coax from the beverage I tested is the best of the lot, running good
glued foil and two sets of braid. I then brought out my new RG59 and I
unrolled it out to the beverage, terminated it and did the same test.
Again, running it through the choke box I was getting S1 - S2 readings.
Not quite as good as the RG6, but still ok, I then touched the ground
rod wire to the shield and again S9 on the locals, but there is no issue
with the coax, it is something else. But I guess I will have to leave it
floating, but the choke box does work and it works well. But I don't
know what channel to leave the receiver on at night. There are too many
to DX. Even KNBR and other stations 90 degrees off from the beverage are
down in signals and there are stations behind them now at night.  The
directivity of the beverage is much more sanitary now. If I am getting
S1 or below on the locals with the coax, there cannot be many stray
signals getting in. But I wish I could fiqure out a way to ground the
shield, but whatever. It does work. Thanks again John for the use of the
choke box.  Fantastic!

73,

Patrick 

Patrick Martin
KAVT Reception Manager

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