[Mobile-Portable] Question about HF mobile - film at 11:00

[Jim Davis]

I agree, mobile installations are a bit more fussy, but I have in the
past used Hustler, Ham Sticks and Screwdriver antennas and have had good
luck with all three. In my opinion the solution is in the ground. Keeping
the ground (braid) to 10 inches or less and attaching it directly to
bright metal on the vehicle body generally produces good results. Wire
brushing these connections two or three times a year sure helps out as
well.

Good luck
Jim/AA7AZ

On Tue, 10 Jul 2007 19:43:27 -0700 (PDT) Paul Goble <goblefam at swbell.net>
writes:
> Chuck:
> 
> I found your treatise to be very interesting!  I just changed HF 
> antenna mounts and am using the same ground connection as before, 
> but now the only bands my screwdriver will tune are 80m, 20m and 
> 17m.  Used to be able to tune 'em all!  What surprises me is that 
> the 1.5:1 SWR bandwidth on 80m is several 10's of KHz more than 
> previously.
> 
> So this is generally caused by insufficient ground?  That is my 
> assumption, but I sure could us a "sanity check" - HIHI!
> 
> TIA,
> 
> Paul ND2X/5
> http://www.nd2x.net/pix/new.jpg
> 
> 
> Chuck Mabbott <aa8vs at yahoo.com> wrote: Mobile set ups can get odd, 
> to say the least.
> 
> How is the antenna grounded?  Mag mount or fastened to
> the bumper?  
> 
> If mag mount on trunk lid the and the ground is not
> sufficient 15, 17 & 20 will tune fairly decent but you
> usually can't get 40 40 below 2. something.  
> Run a ground strap 3/4 - 1 inch wide or better from
> trunk lid to frame of car.  As I recall the ground
> connections have an impedence around 8 ohms so the
> connection is critical.
> 
> <SNIP>
> ----
> Your Moderator: Dick Flanagan K7VC, 
> mobile-portable-owner at mailman.qth.net
> 
> 


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