Date: Fri, 3 Sep 2010 14:50:02 -0700
Reply-To: Old Volks Home <oldvolkshome@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Old Volks Home <oldvolkshome@GMAIL.COM>
Subject: Re: Goofy CB + Coolant LED Stuff! (sorta friday content)
In-Reply-To: <AANLkTimJB9vh3ZbZ+2ZCPDwweoWuzNxHV8XY54z_0mXb@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Neil -
Its spurious RF from your VERY poorly mounted antenna every time you
transmit. That close to the instruments, things can go wacky, even if it's
only 5 watts, because there's virtually no RF shielding in the Print Circuit
Foil and the instruments/lights themselves
In addition, while the mounting the mag antenna on the dash might look cool,
it's gonna play havoc with your Standing Wave Ratio (aka SWR) of your CB's
transmit amplifying the spurious RF emissions, makes your transmit final
transistors work overtime, eventually causing them to burn out (even with
the fail-safe diodes in the radio) and of course reduce your transmit
capability to nil. The antenna has to be mounting outside to work properly
and do away with the spurious RF.
I'm not going to get into extensive discussion of Radio SWR except to say
that the lower the SWR, the better your receive and transmit. Ideal is
1.5:1. Above 2.0:1 is when it falls way off. Above 3.0:1 can damage your
radio. A good communications shop with the proper meter can measure and if
the antenna's adjustable (within a narrow parameter), they can fix it. But
as I said the antenna's gotta go on the outside, preferable mounted on the
rain gutter and not the luggage rack or poptop bvecause you won't get a
proper "groundplane" for the radio to properly work.
If you wanna communicate short distance between vehicles, get a pair of
cheep FRS walkie-talkie radios.
YMMV
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
75 914 1.8 "Nancy"
Full Timing Since March 1999
oldvolkshome@gmail.com
http://www.oldvolkshome.com
***********************************
On Fri, Sep 3, 2010 at 1:58 PM, neil n <musomuso@gmail.com> wrote:
> Hi all.
>
> Bernie and I are on the road having a great time.
>
> Just left camp this morning and was heading uphill when.....
>
> Blinking coolant LED! Ack! (this was a self installed WBX relay/etc)
>
> It would go on for a few seconds, then off, repeat. I alerted Bernie
> via CB. (The one I installed yesterday and connected to the aux.
> battery system) I had also installed a short magnetic base antenna on
> the dash. (works fine for short distance btw. Easy to take down)
>
> Didn't panic as I had checked the engine bay this morning. I knew
> there wasn't anything wrong with the cooling system. But...... it kept
> blinking.
>
> Pulled over. Found that when I keyed the CB, coolant LED would go on.
> Huh. Disconnect antenna, light stopped blinking. Huh. Figured it was
> some kind of current draw affecting the WBX relay (fridge was on DC
> etc.). But this didn't really make sense. Anyway. Decided this wasn't
> a big problem and we continued on. STill puzzled.....
>
> I'm thinking maybe my self installed supply line from aux battery to
> stock fuse panel was some how involved. (really how could that be???)
> Then....
>
> Thought since I had plugged in my DC personal fanto the ciggy lighter
> this morning, it might be involved. Unplugged it, problem gone.
> Reason: DC fan cable was picking up RF from the coax cable!
>
> Is that goofy or what?? ;)
>
> Neil.
>
> --
> Neil Nicholson '81 VanaJetta 2.0 "Jaco"
>
> http://tubaneil.googlepages.com/
>
>
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
>
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