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

[Chuck Mabbott]

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.

If you have the antenna fastened to bumper, double
check the grounds and make sure of a solid metal to
metal contact. Check on strap to frame, or add one.

If there are mechanical connections involved loosen
and retighten them all.  Mobile setup will vibrate
things loose.  The old rule of HPFM will give you fits
so just retighten everything.

Double check to verify the coax [if mag mount] is not
damaged at base of antenna or where it goes into the
trunk.  

That is all I can think of for the moment, but I will
study on it some more.  I would also recomend a SGC or
similar coupler mounted right under the trunk lid near
the base of the antenna for some more options.

--
73
Chuck AA8VS

Note:
HPFM "Hocus Pocus F()*^g Magic!" how these antennas
work anyway.




--- "Brian K. Gaskamp" <ka5bkg at sbcglobal.net> wrote:

> Hello all, I'm new to the list here and also new to
> HF mobile and I'm having 
> a problem that has me stumped.
> 
> I'm running a Icom 706MKII with a Hustler 40m ant on
> my truck.
> 
> I can be in front of my house and I get full output
> on 40m and everything 
> works great...
> 
> I check into a 40m traffic net during my lunch break
> and my power out is abt 
> 50 watts, and swr is 2.3-1...
> 
> I just stumped and what could be happening and need
> some advice, 
> suggestions, on what I'm doing wrong...
> 
> Or better yet, what happens to my HF mobile from the
> time I leave my house 
> and why it acts like it does once I get to work.
> 
> 73,
> Brian 
> 
> 
> ----
> Your Moderator: Dick Flanagan K7VC,
> mobile-portable-owner at mailman.qth.net
> 



 
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