[Mobile-Portable] thin antenna cable

Wed Nov 30 23:20:49 EST 2005

Mark:

I went to a local metal outlet, bought a 30" x 30" x 1/8" "sheet" of
Aluminum, took four magnets I had from an old "H-frame" mag-mount and
put one in each corner of the square.  This raised the aluminum about
1.5" off the roof of the pickup.  I put an "N" feedthrough in front for
the 3-band FM vertical (2M, 70cM, 23cM), and use an "N" rightangle
adapter on the bottom to RG-214 running to the FM triplexer.  I mounted
an NMO mount in the center for the 222MHz 5/8 wavelength and run RG-58
to the antenna switch inside the pickup where I switch the output of the
222 all-mode between the FM antenna (I run barefoot on FM) and the input
to the 270W Pa for SSB.  The rear whip, 1/4 wavelength on 6M, is one of
those quick-disconnect antenna mounts with the SO-239 connector
underneath - I run a UHF right-angle adapter on that and RG-58 to an
antenna switch inside the cab so I can switch from the vertical to the
horizontal (RG-214 to the horizontal).

This antenna plane is solidly in place - nothing short of an F3 tornado,
or rolling the pickup will ever dislodge this.  Not anticipating either
of these tragedies!

In the pickup this one replaced, I went directly through the roof, but
these new vehicles all have the plastic "trim" inside put on with
"snap-in" fasteners.  I can never get these off without breaking them,
so it was going to be an expensive proposition to take the headliner
down and run coax to thru-the-roof connectors!  The big rectangular hole
in the rear of the crewcab make it SO EASY to run cables in-out of the
cab that I simply run three more out the back and up to the roof for the
above-described verticals.

Hope this helps!  If you need it, I can take a few more pictures to
illustrate anything I muddled up in my verbal explanation.....

Best regards,

Paul ND2X/5

Mark Schoonover wrote:
> 
> Paul,
> 
>         How did you mount the antennas above the cab on the roof??
> 
> 73
> 
> Mark
> KA6WKE
> 
> paul goble <mailto:goblefam at swbell.net> tapped at Tuesday, November 29, 2005
> 9:43 PM:
> 
> > Roger a rectangular hole - I took one of the two air vents out of the
> > back of my crewcab passenger compartment, cut a matching hole in the
> > front of the pickup bed, made a flexible weather seal out of neoprene
> > weatherstripping liberally "cemented" with silcon "sealant", and have
> > a 7" x 3.625" opening (rounded corners) through which all cables
> > (coax,
> > power, control, whatever) can be run with impunity.  I probably won't
> > run anything larger than LMR600 (902 and 1296) or superflex (432) for
> > the short runs I have (RG-214 for all lower freqs except RG-58 for all
> > FM).  The open space (that not clogged with cables of all types) is
> > jammed with a big kitchen sponge.  Sounds strange but works great!
> >
> > Kinda tough to do this in a Mercury, Saturn, Toyota, Nissan, whatever,
> > automobile though - HIHI!
> >
> > See the mobile antenna farm at http://www.nd2x.net/pix/new.jpg - the
> > obligatory FM antennas are the front two verticals on the roof of the
> > cab (no holes in the cab roof - mag-mounted a 30"x30" sheet of 1/8"
> > aluminum to the roof and mounted all the verticals on that) - the 6M
> > vertical can be used for both narrowband ("real") communication and
> > FM.
> >
> > Remember, I kid a lot - I tease "shack-on-the-belt" types all the
> > time -
> > it's a mental shortfall caused by spending the first 14 years of being
> > licensed exclusively on 6M, mostly mobile; I miss good ol' Lafayette
> > Radio - that Heathkit SB-110 was nice, but a tad large for mobile.
> > Wish
> > I had kept my 4-ring EBCO halo!! - HIHI!
> >
> > GN&73,
> >
> > Paul ND2X/5
> >
> > "J. Gordon Beattie, Jr." wrote:
> >>
> >> Hi Folks!
> >> Here is another idea for passing cables up through the underside of
> >> your car: Drill holes in a square or rectangular shape, then using a
> >> piece of small heater hose, slit the hose and then cut it to the
> >> length of the perimeter of your hole.  Presto! Instant Grommet!
> >> Then you can run LDF5-50 or larger through it with the connectors
> >> on! :-) 73,
> >> Gordon Beattie, W2TTT
> >> 201.314.6964
> >> w2ttt at arrl.net
> >> w2ttt at att.com
> >>
> >> -----Original Message-----
> >> From: mobile-portable-bounces at mailman.qth.net
> >> [mailto:mobile-portable-bounces at mailman.qth.net] On Behalf Of paul
> >> goble Sent: Tuesday, 29 November, 2005 23:17
> >> To: Mobile-Portable Reflector
> >> Subject: Re: [Mobile-Portable] thin antenna cable
> >>
> >> On the lighter side:
> >>
> >> There are those of us running LMR600 on 902 and 1296 MHz....
> >>
> >> One might find it more practical to punch (greenlee) 3/4" holes in
> >> the FLOOR of one's vehicle, running cable through "rubber" body
> >> plugs (great weather seal).  "N" connectors don't fit thru the 3/4"
> >> hole and must be installed after running the cable.  Then mount
> >> antennas on brackets
> >> mounted to strong points under one's car and run aforementioned coax
> >> up
> >> the mast to antennas.
> >>
> >> .....of course, it's just easier to drive a pickup and not worry
> >> about cosmetics - HIHI!
> >>
> >> On the other hand, if it's for FM, why worry?  6-10dB is of only
> >> minor consideration on FM since it is a STRONG signal mode.....use a
> >> "thru-the-glass" vertical and forget about real antennas.....
> >>
> >> Oh, just to keep stirring this particular pot, remember that "REAL
> >> mobile antennas are omnidirectional".
> >>
> >> OK, so I kid a lot, but the disparaging remark about FM stands - HI!
> >>
> >> Best regards,
> >>
> >> Paul ND2X/5
> >>
> >> W6OAL at aol.com wrote:
> >>>
> >>> Walter,
> >>>
> >>>     As you are experiencing mobile antennas and mobile  operation
> >>> is a compromise in the first place. It would behoove you to get
> >>> antennas and cables as far from the engine compartment as possible.
> >>> I have an  Izusu Trooper (SUV) in which I run an FT-897 and operate
> >>> 40M thru 70cm. My  thing is to run the cables (RF) RG-400 and/or
> >>> RG-142. They are fairly low  loss. I don't know about using that
> >>> ultra thin stuff, much power and it seems to  me that one might
> >>> have a fire to contend with. The dielectric of what I use is  solid
> >>> Teflon. The shield is a tightly woven silver washed copper braid.
> >>> These  go from the rig back along the drive shaft tunnel and under
> >>> the back seat  to the rear hatch (door -whatever), up the hinge
> >>> channel and under the rubber  gasket to my antennas which are
> >>> mounted on some Comet (many degrees of freedom)  mounts. That
> >>>     rubber gasket fits over a seam of sorts. I have notched it with
> >>> a  rat tail file to accommodate the coaxes. Leakage is not or at
> >>> least as of yet  has not been a problem. And, so there might be a
> >>> little loss. Your mobile  isn't going to be used for any sort of
> >>> competition work anyway so what is a  little loss here and there.
> >>> Look at some of these commercial mobile  installations, -6 dB is
> >>> the norm and acceptable loss in what they call a good
> >>> installation. You probably won't have all that much even if you use
> >>> RG-58.
> >>>
> >>> CU 73, Dave...
> >>>
> >>> Olde Antenna  Lab of Denver
> >>> David A. Clingerman, Sc.D.  (CEO)
> 
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> Your Moderator: Dick Flanagan K7VC, mobile-portable-owner at mailman.qth.net