Inverted L

[W2INR]

I just put up an Inverted L for 160m .

I have tuned the ant for 1900 and I have a good match. 1.2 : 1 at 1900. I have 60 radials as the counterpoise. I can't run the horizontal portion of the ant horizontal. It comes down at an angle starting out around 65 ft high and ending up around 30.


The question:

Since the horizontal portion of an Inverted L is acting as an capacitance hat, does the orientation of the horizontal piece really have to be horizontal?

[ve6pg]

..I DONT BELIEVE SO..I HAVE A 40M VERTICAL,32FT.  IN PARALLEL TO THE VERTICAL PORTION,I HAVE A 1/4 WAVELENGTH WIRE,RUNNING UP THE SIDE OF THE VERTICAL.,THAT IS CUT FER 1885. IT RUNS UP ABOUT 30 FT,CLIMBS UP TO A PINE TREE,ABT 50FT,BACK ACROSS THE YARD IN A ZIZ-ZAG FASHION. THE THING HAS DEFINITE VERTICAL PROPERTIES. WERKS FB ON 160. LOCAL STUFF,ISNT GREAT,AS YOU MIGHT IMAGINE..LONG HAUL STUFF ON 160 IS FB! I HAVE A SIMILAR WIRE ON THE OTHER SIDE OF THE 32FT VERTICAL,CUT FER 75 METRES. THE WHOLE ANTENNA WERKS 160-6M.THE LONG HAUL STUFF ON 75 IS QUITE AMAZING...NOW,I DO HAVE ALOT OF RADIALS/COUNTERPOISES,BUT I THINK THIS IS A FB ANTENNA FER A GUY WITH A RESTRICTED LOT,DUE TO SPACE....TIM...SK..

[K1JJ]

NOTE: Please refer next post AFTER this one. This post was written thinking Gary meant a 30 degree angle UP for the second half of the leg, not DOWN dropping to 30' off the ground. But it will be left here for archive info in case someone has this same situation in the future.
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G,

By changing the second half of the L from flat to a 30 degree angle will only change your vertical pattern components somewhat. It will now more closely resemble a full vertical more than a horizontal pattern.

It will now be even more dependent upon your ground system for performance.

The "capacity hat" is really a name for the horizontal length and has little effect on the resonant frequency. The resonant freq will probably creep up slightly, simply cuz there is less coupling/capacitance to ground now, but still does it's job of increasing the feedpoint impdeance.

I know plenty of guys on 160M over the years running FOUR ants like you have in a four square. They take a single tower, and pull out four wires from the top on a 45 degree angle, and feed them at the bottom in four square with a Com-Tek box, or whatever.  Works fb and not too far off from standard verticals in a square in modeling.

Bottom line is that you are OK, but will be slightly piss weaker to the locals now that you're taken some more horiz component out.  Don/KYV will be giving you some big reports, howver...    It will be a wash here in CT I expect cuz of the 350 mile distance on 160M.

BTW, I'm making my new 4X1 rig easily bandswitch-able to get up on 160M wid you in a month with the dipole at 190'. Big mawl, caw mawn.  Looking forward to it and glad you put the effort in to get back on 160.

T

[K1JJ]

Whoops, solly. I thought you meant 30 degrees for the horiz leg, not 30'.  But, I'll leave that post there just for the archives.

With the leg rather coming DOWN from 65', it will have a tendency to cancel the other vert portion. Picture it if it came down so sharp that it formed a transmission line - then the antenna wud act like a 65'  1/8 wave vertical with a low input impedence. 

So, it's a matter of degree. I expect your input impedence has dropped, more IR loss and the pattern is not as clean. Yours is at a half way point and like an inv V with legs that are at 45 degrees. That's the limit before serious cancellation. You're OK.

What it is doing now is acting as a loading device, which is FB.  Kinda similar to HUZ's adding vertical legs to the end of a dipole, but in this case they are not at perfect right angles, thus the anonolies.

You will be losing some horiz component to the pattern.

Bottom line, is that it is always better to have a greater angle than 90 degrees between two legs than less. But you will do fine with it, being a full quarter wave and the fact that you put the effort in for a good radial system...

You will be channel master whatever you do there, G.

T