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From: John Rabson <john.rabson07@gmail.com>
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Date: Thu, 28 May 2015 16:24:28 +0200
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To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: MF mobile ?
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> I recall a few years one of the British Telecommunications journals (POEEJ/BTTJ/IBTE/TCNJ - I forget which name it was using at the time) had an item about a low-loader mounted LF/VLF station which had a radiator supported by a helium balloon.  Or was it the Navy's definition of mobile: anything you can move around with a battleship?

John F5VLF

> On 28 May 2015, at 00:10, DK7FC <selberdenken@posteo.de> wrote:
> 
> Hmm, i find someone should do a real mobile (mobile-mobile, with a velocity > 0) experiment. A 1.5 m long CB antenna with a special preparated feed point should work. And i think that the wire works better with a fixed C in parallel, even if this reduces the efficiency. But it stabilises the SWR or better said, the voltage on the wire. Corona? Where is the problem with corona? :-)
> Markus, could you calculate the ERP when 10 kV rms is applied to a 1.5m high antenna on a car roof? I bet you have all the formulas in your mind :-)
> 
> Maybe the antenna has 10 pF. I remember i have a 470pF/16kV capacitor at home. So if C = 470 pF and f = 475 kHz, L = 239 uH With 470 pF parallel to the antenna, a moving wire (= changing C) does not make a significant effect i think.
> 10 kV at 239 uH at 10 kV is 14A. If P = 200 W, the losses must be 1 Ohm ! 
> With a good RF litz wire, this is possible :-)
> 
> What would be the ERP and possible distance?
> 
> It would be interesting to try that in WSPR / QRSS-60 :-) I would also drive to someone for making a CW QSO but most likely there is a LOT of QRM when driving...
> 
> More ideas?
> 
> 73, Stefan

john.rabson07@gmail.com

Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and ROBSONNE