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Re: [TowerTalk] M2 20M5 SWR

To: "Jorge Diez - CX6VM" <>
Subject: Re: [TowerTalk] M2 20M5 SWR
From: "Bill K2OWR" <>
Date: Thu, 31 Dec 2009 10:56:21 -0500
List-post: <">>
:::: My guess? The six pack is notorious for intermittent relay contacts.
I had several of them for years and I was always needing to yank the 
feedlines around on them till the rcvr would come back to life or the sudden 
high swr would go back to normal.

For a while I found that raising the voltage to 15volts or so would make it 
behave better, but ultimately we just learned to notice when it was 
happening, go to where the boxes were, and smack them around a little :-)

Seriously though, unless you really need them, like for two operating 
positions, I would try to use an old fashioned coax switch instead. This is 
just my personal experience, but we found a lot of others who went thru 
this. This was 5 years ago, but maybe they made them better now?


----- Original Message ----- 
From: "Jorge Diez - CX6VM" <>
To: <>; <>
Cc: "'Hector Garcia XE2K'" <>
Sent: Thursday, December 31, 2009 10:38
Subject: Re: [TowerTalk] M2 20M5 SWR


I just returned to do some measurements.

I have right now installed my back up radio (TS450), with a Diamond SWR, a
Drake L7 amp and a WX0B sixpack

All the reports I read before, where from my swr meter in the TS450, that
displays many bars to up to 2.5-2.9:1 SWR.

But today I notice that is only when the sixpack is connected

I put the antenna direct to the radio and the SWR is 1.4:1 in 14000 and
1.8:1 in 14400 in both TS450 meter and Diamond SWR meter.

This also happens with my 15M6 antenna: with the antenna to the sixpack it
have in the TS450 meter a SWR of 2.5 in 21000 to 21400.  With the antenna
direct to the radio it have 1.2:1 from 21000 to 21300 in both TS450 meter
and Diamond SWR meter.

What´s wrong?

I change the loop that go from the Diamond SWR to the sixpack and is the
same, so the problem is not in this coaxial.

Any idea why with the antennas to the sixpack the radio meter display high
SWR? (here the Diamond display the 1.4:1 in 14000 so is only in the radio
meter this difference when antennas going to the sixpack)

I fully rotate the antenna and SWR was constant in all the 360 degrees (just
a little diference from 1.4:1 to 1.6:1 I think is not a problem)

Anyway in next days I will change the 20M5 to be in parallel with the XM510


-----Mensaje original-----
[] En nombre de
Enviado el: Lunes, 28 de Diciembre de 2009 11:05 p.m.
Asunto: Re: [TowerTalk] M2 20M5 SWR

Is the SWR OK higher in the band or bad all across.  If it is bad all over
it is possible that the 10m boom is interacting.  I think that the Cushcraft

elements are not insulated making it difficult to guess if there is any boom

interaction without modeling the system. Why is the 10m antenna at 90
degrees?  There should be little interaction if they are parallel and it is
easier to operate the station when the rotators have the correct reading.

John KK9A also P40A

To: <>
Subject: [TowerTalk] M2 20M5 SWR
From: "Jorge Diez - CX6VM"
Date: Sun, 27 Dec 2009 15:40:23 -0200
List-post: <">>


I installed a M2 antenna, 20M5 at 33 mts.  I assembly it for FULL BAND

I have in the same tower a stack of three XM510 monobanders for 10 mts, the
top one is 3 mts over the 20M5 cross at 90 degrees from the 20M5.

At 14000 I have 2.9:1

This will be because of the other 10 mts antennas in the same tower?  Or at
FULL BAND the 20M5 have this swr at 14000?






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