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PA2RHB > WANTED 24.09.04 20:12l 39 Lines 1464 Bytes #999 (0) @ WW
BID : 030044PA2RHB
Read: GUEST
Subj: Re: 70MHz Horizontal - oops
Path: DB0FHN<DB0RGB<OK0PPL<DB0RES<ON0AR<PI8WFL
Sent: 040924/1906Z @:PI8WFL.#NH1.NLD.EU #:48681 [Enkhuizen] $:030044PA2RHB
From: PA2RHB@PI8WFL.#NH1.NLD.EU
To : WANTED@WW
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I'm glad that Dick, VK3ABK, sent another message on the subject, because I
did not remember his call and did not keep the older messages.
He said:
> Eldred asked for details of a 'HORIZONTAL ANTENNA'for 70MHz mobile.
> I must admit that I took this to mean 'mounted' horizontally, not
> polarized horizontally.
This is where the 'oops' comes in - I did not think of that possibility AT
ALL, and it may well his only requirement. It would be consistant with the
not-wanting-to-hit-tree-branches bits.
In that case the DDDR would be the correct choice after all, Dick.
With Andy, G0FTD, I agree that a horizontal antenna for 4m, mounted just
30cm over a groundplane, gives 'not much' lowish-angle radiation. Exactly
where the -3dB point does not change the fact that it is too high. I must
have been thinking of repeaters on high buildings along the streets ;-)
(horizontally polarized? oh, well)
I quite liked the idea of a vertical wire down the middle of the
windscreen, coupling energy into the car body for it to radiate. Some
horizontal radiation will show up too, but not much directly fore-aft.
Coupling your RF into the rear window heater is interesting too. I would
guess that the losses would be higher though.
Well, I suppose that now we'll have to await Eldred's response and see if
we were of any use to him at all.
Rudolf
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