[IRCA] Choke Box update

[mwdxer@xxxxxxxxx (Patrick Martin)]

Greetings everyone,

After using the choke box from John, I ordered four FT-140A-J pieces
from Amidon in So CA for $4.50 each plus shipping (total $27), and
wrapped 16 wraped of RG174 on the piece and intalled it in a Radio Shack
plastic box with SO 239 fittings. YES! they work. Very nicely. 
   The one thing I have noticed, is my over all noise level is down. Not
by a huge amount as I don't have much noise here, but little buzzes and
things that are not always a problem, but you notice them. Even the
electric fence noise is less when turning off the noise blanker on the
R8, but it is generally left on.  Any noise on the coax pretty much runs
to ground now.
   In testing each piece of coax for stray signals, I cap the far end
disconnecting it from the matching transformer and putting a terminator
(F fitting) on the end. I then, running the coax directly to the antenna
input was getting S7-S9 on the three locals. Running the coax through
the choke box, I am down to threshold on the local TIS, to the strongest
being KAST 1370 1 KW 5.1 miles away at S1. The other two locals are
weaker with background noise in the signal. No signals of anything else
on the AM dial/  
  In the case of the 4 antennas. 
(1)   SW EWE, for the first time in a number of years, the signal coming
in is more directional down the coast, like in the case of 630 khz
KWRO-Coquile OR (230 miles), vis KCIS Edmonds WA (150 miles). KWRO is
always on top, but the co channel QRM from KCIS has gotten stronger the
past few years. I think they may have moved their site, but still,
getting rid of them 100% has not been easy except with phasing. Now it
is a stronger dominant KWRO with KCIS weakly way behind KWRO. Like 10-15
years ago. The same is true with 1030 khz, KDUN-Reedsport is much better
now with less KMAS Shelton WA behind it. I am very pleased with this.
(2)   WNW EWE, the signals like from Portland are weaker than before.
The antenna pattern seems much more directional now. If we ever get out
of these high Sunspot numbers, I can see how it does for Northern
Asians, but of late I get too much AU noise off that antenna in the
mornings. 
(3)   Eastern beverage. All I can say is WOW!!. So many of the
frequencies at night now are mumble jumble of stations, with less
dominant ones. Cuba 640 seems to be common about every night of late. 
During the day I get KRCO Primeville OR (200 miles- 1kw)  nearly 40% of
690. CBU is still on top (50 KW directional this way at 160 miles) but
not nearly as dominant. KACI 1300 The Dalles (150 miles-1KW) tears KKOL
Seattle (105 miles 50 KW) up a lot more now too. So the directivity of
the Eastern beverage is better than it has been in years. I always
thought raising it made the directivity worse. It may not have had the
effect I first thought it did.
   Also getting rid of the those banans plug pigtails made a difference
too. I went back to all F fittings.  Two matching transformer boxes are
metal (Bev & SW EWE) and two are plastic (WNW EWE and vertical). 
 As it gets closer to Fall and we get more rain, I will see how it
works, but it sure has made a difference. 
(4) 45' vertical, Of course the directivity of that has not changed a
whole lot. A vertical is a vertical in most cases, but it is quiater
now. I have noticed that. The weaker signals are cleaner.
   So far I have only built two choke boxes and both side by side are
connected to the antenna SO 239 fittings on the back of the R8 for each
antenna input. Everything runs through the choke boxes now.

I thank John Bryant so much for the loan of the Choke Box.  My eyes have
been opened, to say the least on the stray signals getting into coax.

73,

Patrick
(One happy camper!! Now bring on the DX!!!!)

Patrick Martin
Seaside OR

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