Topband: Inverted L Question - Reply

[Ulrich Weiss]

hello Guy,

I have been using a 3/8 Lambda Inverted Vee on my telescoping 55 foot tower 
(with a 5 Band Quad on top) for a couple of years now... I'm well aware of 
the fact that there is a significant amout of coupling between the 
Inverted-L and the tower... but as they are connected to the same ground 
system, I do not see where power ("5 or 10 db lost") should be wasted...
considering to try your FCP on the Inverted-L I have obtained the cores for 
the transformer, but the current discussion makes me doubt that it will be 
helpful as the tower is still connected to my (buried) ground system... do 
you think that detuning the tower (with the lines going up bonded to the 
tower) might improve the situation???
BTW, I do not mind the horizontal part of the radiation as it seems to help 
me a lot in 160m-contestst to work the numerous EU-multipliers... DX-wise I 
am not entirely unhappy as I have be able to work almost all the rare stuff 
in and outside of contests, but, of course, the better is the enemy of the 
good...
kind regards

Uli, DJ2YA

----- Original Message ----- 
From: "Guy Olinger K2AV" <olinger at bellsouth.net>
To: "Lloyd Korb" <k8dio at roadrunner.com>
Cc: <topband at contesting.com>
Sent: Sunday, April 29, 2012 10:22 PM
Subject: Re: Topband: Inverted L Question - Reply


> The normal innocent presumption would be that your feedlines and other
> miscellaneous conductors are not involved in your patterns.  But if your L
> and your 6BTV are engaged in a horse race on 160, your tower/L is really
> not doing well, and has the typical loss problems for that setup.
>
> My personal inverted L is out in the woods away from everything, without
> radials for that matter, uses an FCP.  It simply blows away anything I 
> have
> ever used on 160 on this property, nothing close.  There is nothing
> intrinsically inferior about an L.  Yes there is something about a few
> tenths of a dB down from a completely vertical 1/4 w radiator,  but your
> case sounds more like 5 dB lost or 10 dB lost.
>
> You are likely hearing a LOT off the OTHER feedline shields (because they
> are also close coupled to the L vertical) and effected by miscellaneous
> conductors in the vicinity.  You shouldn't have any real expectation of a
> clean vertical doughnut pattern, and miscellaneous conductors NOT sturdily
> blocked for common mode current will have you listening everywhere,
> including to all the garbage on the safety wire of your house wiring.
>
> 73, Guy.