[Towertalk] Tribander anomaly

[Jim White]

can you easily swap feedlines - can you take an out[put rating of exactly
100 W at the stn and then see if the saem number of resulting watts exist at
the end of both of the coaxes?

I woulod suspect the feedlines - altho the 40-2CD is notorious for being to
load up on almost any band!  We have used it to spot multipliers on 20
meters while the main rig was on the 20 meter stack...

K4OJ



----- Original Message -----
From: "W4ZW" <w4zw@comcast.net>
To: <towertalk@contesting.com>
Sent: Wednesday, May 08, 2002 4:01 PM
Subject: [Towertalk] Tribander anomaly


>
> I have an antenna/tower question for a change of pace.
>
> I discovered quite by accident that 15M signals are better on my 402CD
> CC 40M beam  than on either of the A4S tribanders I currently have up.
>
> I was listening  to a pileup the other evening on 15m and realized I was
> on the 402CD.  Switched to the A4S which is 12' below it and the signals
> dropped a full S unit.  Wow, that's strange.  I just recently rebuilt
> all the antennas that were pretty much destroyed in a tropical storm.
> New aluminum, hardware and feed lines.
>
> The 402CD is rebuilt and on a Glen Martin rooftop tower about 70' above
> ground which is about 18' above sea level in my back yard.  I'm ocean
> front directly on the Gulf of Mexico on the southern tip of an island
> with ocean and bay in all directions except NNW.
>
> I switched to my second A4S (not rebuilt, but one I kept in the garage
> for Field Day) that is on a Rohn mast about 6' lower than the first A4S
> and about 35' away  to the SSE.  Same signal level as the first A4S.
> Switched back to the 402CD and the DX signals pop up out of the noise.
> Does the capture area of the 402CD make that much difference?  My wire
> antennas are still down so I can't compare there, but as soon as the 80M
> Bob tail and the full wave delta loop are be back up I intend to explore
> them as well.
>
> SWR on both the A4S's are essentially flat 1:1.  They are super on 10
> and 20 compared to the 402CD, but on 15M the 40CD2 is clearly the better
> receiving antenna.    The 402CD has a 2.6:1 SWR on 15M and is easily
> loaded with the auto-tuner on the FT-1000D.  Of course it loads pretty
> well on 12M and 17M as well.  Maybe the 402CD should be called a
> quadbander, hi!
>
> Any ideas?
>
>
> Jon Hamlet,  W4ZW
> Casey Key Island, FL
>
> "A little bit of Paradise in the Gulf of Mexico"
>
>
>
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk