Topband: "T" vs Inverted "L" over FCP

[Herb Schoenbohm]

Charles,  I have never heard of any case on TB where a inverted L is 
superior working DX to a well constructed T.  Even if you have a slope 
to the horizontal portion, remember it does not radiate as much as the 
vertical portion.  One thing, however, to keep in mind that with with 
the top portion looking sort of like inverted "V" there will be 
significant cancellation if the angle is too acute and the wire too 
long.  Here I personally use  a 25% rule for sloping top hats as much 
beyond this does not buy you any enhancement especially as you approach 
the 45 degree angle cut off.  I don't think there will be a problem for 
you if the angle of declivity is small and if the ground system is adequate.

  There is nothing wrong with compensating for a shorter horizontal 
portion, fed exactly in the center, by using a high quality loading coil 
at the feed point.  He using A/C copper tubing is fine, and even better 
if you silver plate it.  You can go to ground with one side of the coil 
and tap up on it for a good match.  This will also provide some degree 
of lighting protection to the shack . Either way you will need a good 
ground system or counterpoise in order to perform well on TB.

73

Herb Schoenbohm, KV4FZ




On 11/30/2012 1:05 PM, Charles Damico wrote:
> Just wondering... I'm thinking about possibly using a T configuration instead of an Inverted L over an FCP.  I just don't have a straight, unobstructed 85' for the horizontal leg of the L.  Each leg of the T would not be flat-top, rather would resemble a high angle inverted V (about 150-deg).
>   
> The FCP was constructed a couple of months ago, but I never got around to installing the radiator portion.  Any insight/suggestions would be welcome.  Too late for ARRL 160, but maybe CQ??...
>   
> Thanks,
>   
> Chuck  AJ1E
> _______________________________________________
> Topband reflector - topband at contesting.com