From: flloyd@l1-a.West.Sun.COM (Fred Lloyd [Phoenix SE])
Newsgroups: rec.radio.amateur.misc
Subject: Re: Antenna mounting ideas for Ford Explorer?
Date: 16 Nov 1992 19:01:06 GMT
Organization: Sun Microsystems, Phoenix, AZ
NNTP-Posting-Host: l1-a.west.sun.com
Keywords: explorer

In article <BxoJLt.HA6@hpuerca.atl.hp.com> jab@hpuerca.atl.hp.com (Alan Barrow) writes:
>
>Having recently traded my Nissan Pathfinder with dual NMO's on the roof
>for a Ford Explorer, I am pondering antenna mounting schemes.
       ^^^^^^^^^^^^^

Congratulations, you're a bona-fide yuppie now! :-)


>
>Has anyone found a great way to do this?

Yes, I have.  Since I'm on my _second_ explorer already, I've finally
seen the light (dome light that is...) and punched the hole in the
roof.  I must say that in all honesty I couldn't be happier with
this arrangement.  I used a Greenlee 3/4" chassis punch which made
a beautiful round hole.  The cable runs down the door post on the
passenger side to the radio which is mounted on the floor under the
front passenger's seat.  The control head is mounted on the ashtray
which allows it to slide in and out for easier operating convienence.
(Radio is the TM-741A)  The antenna is the little dual band Diamond
which looks just like a cellular antenna.  Performance is roughly
like a 1/4 wave on 2M and 2x5/8 on 440.  The nice ground plane effect
of the roof gives impressive performance.  I have no trouble driving
in garages with this (17") whip on top.

In my previous Explorer, I had a Larson PO-2/70 mounted on the left
front fender, opposite the broadcast antenna on the other side.
Performance was so-so and the radiation pattern was irregular due to
the shape of the fender.  I also had significant problems with RF
interference.  On key down, 45W w/2M, the rear windshield wiper
would actuate.  On the highway, the cruise control would drop about
5 MPH when I keyed down, and the gas gauge would peg to the right
beyond the Full mark.  Upon doing some experimenting, I found that
whenever the connection was terminated at the mount, or if a mag-mount
was attached to the PO connector and the antenna moved to the roof,
the problems went away.  Conclusion: RF bouncing around inside the
cab when the antenna was mounted on the front fender.

When I took delivery of the second Explorer (a replacement for the
first which had too many factory defects), I didn't hesitate for
a minute.  The new antenna was going on the roof....

>
>Some ones I see are:
>
>   1) Brute force- NMO's in the roof just above the dome light.
>   I may do this long term, but do not want to do this right away.
>   (I want to decide where I *really* want the antennas. Holes are
>   so permanent!)

Real hams drill holes.  Fear not, NMO mounts can always accept a
cheap cellular antenna if you decide to sell.  Short buyers can't see
the hole on the roof anyway :-).

>   2) Larsen "L" bracket above the rear lift gate. The lift gate does
>   not open past 90 degrees, so it would work.

Waste of time.  Poor ground plane shape, bad pattern.  Crimped cables
in door jam.  Long cable from fron to rear.  Aren't you planning on 
keeping this car?  :-)

>   3) Some type of roofrack clamp. How would you get the cable outside?
>   I do not want coax running out the rear lift gate to the roof rack.
>   Maybe drill a hole for the coax through the roofrack body (and roof).

If you're going to drill then putting in an NMO is a far better idea.
you can't seal a coax hole very easily...  NMO mounts are _very_ proven
and standardized.  You can mount any of a variety of antennas on them.

>   4) Larsen "L" bracket in the hood crack across from the BC antenna.

See account above of RF in the passenger compartment (Swish goes the
rear wiper...)

>
>   5) On Glass- not interested. (want to use existing antennas)

Have never seen a really good one.  Assymetric radiation pattern.


>   6) Mag mount- Not interested. (want permanent install)
>
Mag mounts scratch paint.  They do more damage in the long run than a hole.


>Down the road I need to consider an HF antenna as well. On the
>pathfinder I had a strong aluminum mount on the spare tire carrier hinge
>mount. No such beast on the explorer. I suspect a roof rack type clamp
>for HF use.

I'd look into a rear frame mount.  I just had a Reese hitch put on and
it's got plenty of support for an antenna.

Good Luck!

-fred


-- 
[ Fred Lloyd, AA7BQ                             Fred.Lloyd@West.Sun.COM ]
[ Sun Microsystems,           Southwest Area Solaris Transition Manager ]
[ Phoenix, AZ         - The future starts today! -       (602) 275-4242 ]
Newsgroups: rec.radio.amateur.misc