That's a great way to start. Especially as the solar cycle fades and 10/15
are not open. Then in the day, you run 40/20, and in the night you run
80/40.
73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie
-----Original Message-----
From: rob
Sent: Friday, October 02, 2015 1:21 PM
To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] Coax Stubs for SO2R
On 9/8/2015 5:22 PM, Peter Voelpel wrote:
That shorted stub cut for 20m has to be installed on the 20m station
(station B) to suppress 40 and 15 there. On the 40m station (station A)you
will need an open stub cut for 20m to suppress 20 and 10m interference.
Both stubs will be around 23 feet long when made from RG213,
What would you recommend if you had 2 el 40 on one tower
and tribander
on second tower. I have considered experimenting with
so2r but just 20 and 40
meters to see if I can handle it.
BoB WA1FCN
73 Peter -----Original Message----- From: CQ-Contest
[mailto:cq-contest-bounces@contesting.com] On Behalf Of Mike Smith VE9AA
Sent: Dienstag, 8. September 2015 23:14 To: towertalk@contesting.com;
cq-contest@contesting.com Subject: Re: [CQ-Contest] Coax Stubs for SO2R
Thanks for the many replies so far. So today after I got home from work I
tried just running radio A @ about 1w on 7.000MHZ and saw S9 on 20m and s1
on 10m. No change switching stub in or out, so I took Jim's(K9YC)
suggestion and moved the stub farther away from the transceiver. I made up
3 random length patch cables and so have the stub roughly either: 10-12',
15'-17, 20'-22, 25'-27 away from the transmitter (Radio A). (rough
guesstimates) ( a 1/4wl, accounting for VF would be in the 23'-27' range)
No perceptible change whatsoever at any point in the line no matter where
I put the stub. Just the slightest SWR change when I put it in line.
Almost cannot detect it. I am going nuts. It's either something in the
shack or something outside rectifying (I guess?) but these are pretty low
power levels. (usually 100w, but also at 1w !) Radio A (transmitter in the
scenario) is hooked to an amp (not turned on in close to a year), an
antenna switch, a tuner/wattmeter (used on straightthrough function only,
just for it's wattmeter/SWR function.) Radio B (receiver in this scenario)
is hooked to its own power supply and coax straight outside to a multiband
dipole some 100' from the Radio's A's various antennas. No SWR meters,
switches or anything. They share a 4" hole in the wall in the garage where
they exit to the outside, where the RG8 or LMR400 coax;'s could be close
to one another. They share 120VAC in the shack (but different power
supplies) I have two additional (perhaps important?) questions. Should any
of these harmonics between any bands sound pure and "clean", like a real
CW signal? Mine all sound low/muffly, wide, growly, like they have
buzzing/humming AC riding on top of them. Additionally, the AA-230pro's
manual says to make the 1/4WL stub with the end of the coax OPEN. . . .
.but then for the purposes of these tests, I am using the stubs shorted.
Maybe I have a ground loop somewhere and there is feedback or an isolation
problem on the shacks's 120VAC line? Mike
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