[aprssig] Mounting 2M Xcvr in '05 Toyota Camry

[J. Gary Bender, WS5N]

I have wondered if the placement of the car's broadcast antenna is any indication of possible problems.  I noticed that all Honda and Toyota hybrids have external antennas mounted away from the engine.  In the case of the Honda, at least, that is how the salesman spotted hybrids to show me.  My VW diesel has the antenna at the back of the roof, too.  I have not noticed if that is only on diesels, however.

No problems with 50 watts on 2 meters with the VW TDI.  Have not tried the HF mobile yet.
--
    J. Gary Bender, WS5N
    DM54rp
    Fence Lake, New Mexico USA


On Wed, 26 Jul 2006 15:56:01 +0100, Dave Baxter wrote:
> Hi...
>
> As an EMC type, and a QRO RF technician, plus knowing more about
> some vehicle electrics than I care to admit, I say this...
>
> If you get *Any* "odd" behaviour of the car when transmitting,
> either stop transmitting or reduce power levels till the "Odd"
> behaviour goes away.  Then, at the earliest possibility, review the
> radio installation to keep RF away from whatever vehicle system was
> affected.  Until such time, do not use the radio at those power
> levels, or at all, if the problem is really bad.
>
> You are unlikely to "Fry" a car's electrics, or (any of the many)
> computers, but you could in extreme cases cause the engine
> management to go funny, or cut the motor if it gets really upset.
> The worst could be that you are left stranded with a fault light
> on, and being unable to restart the engine until a dealer or other
> techie type resets the management fault log.
>
> That is for any vehicle, petrol(gas) or diesel with a fly-by-wire
> engine, as most are built nowadays.  Such problems as your dealer
> says, if attributed to your after marked radio installation are
> unlikely to be covered by the makers (dealers, or third party)
> warranty scheme.
>
> The usual things that can happen, are indicators flashing too fast,
> or not at all in the presence of high levels of RF, false
> indications of engine revs or other information, and things like
> wipers, window or seat controls not working as intended.  Not
> usually a safety critical problem, but the distraction it can cause
> can be a safety issue.
>
> You are more likely to suffer higher than expected levels of QRM
> from the car, to the radio on RX, than cause the car problems.
> Particularly bad, are some common rail diesel engines, as the
> injectors use a high voltage to operate, and the SMPS in the
> management box, can radiate somewhat on HF.  In EMC terms, things
> don't radiate much (if at all) below 30MHz, but there again, those
> test limits are set to protect broadcast signals, not the low level
> comms stuff we are interested in.
>
> As has all been discussed at length here and on other lists, take
> great care with the DC power feed, and RF grounding.  In
> particular, if you run the -ve lead for the radio direct from the
> battery, fuse it!  You wouldn't be the first to melt a radio or
> accessories when starting the engine if the normal battery ground
> strap is anything less than perfect...
>
> Take care..
>
> Dave G0WBX.