On 11/20/2011 4:32 PM, Dave wrote:
> More like EMC issues, affecting the engine ECU, or a critical sensor, so
> it cut's the engine to be safe.
>
> Too much RF power for the car to safely handle. Do you realy "Need"
> 500W out mobile? The sort of near field that creates, will affect all
> sorts of things, not just your car either!
500 watts? I'd much prefer the legal limit. The mobile is one place
where your signal can use the help from every watt it can get. OTOH here
in the states there are the required exposure limits that you'd either
have to calculate or measure to be legal and in city traffic you'd
probably be pretty limited to stay legal. Not that anyone would ever go
over the exposure limits.
I remember the guy who had the Cadillac with a complete S-line including
the 30S1 in it. I think it may have even made QST. (50's or 60's) I'm
sure he's not the only one to run QRO mobile.
When it comes to mobile I've always been of the opinion that it's
considered QRP if you key the mike and the tires don't skid.
> You should however try some good RF filters on the DC power cables, and
> take great care over the RF grounding, especialy the antenna, after all,
> what amps of RF current you pump into the antenna, a very similar ammount
> also has to flow arround the metalwork of the car, and that too will
> create some "interesting" field's in places.
Today's unibody construction often works well for RF ... IF they did a
proper job of welding. That's questionable though as the welds (even by
computer controlled robot) can vary. Not as much as those made by
individual workers though. (I've worked on an assembly line although it
was many years ago) OTOH not too many years ago I purchased a new car
and discovered the floor pan had never been welded in place (or sealed).
I discovered that after going through several water ponds on the
highway. I was on my way to work when I realized I had wet feet and the
water was about 4" deep "inside the car". Good thing I didn't have any
papers or rigs on the floor.
> Chances are your car was only tested to 50 W of RF out to a car mounted
> antenna above 30MHz. Depending on it's age and where it was built, and
> for what country.
In the distant past, on many an occasion I've run 160 to 200W on 2-meter
mobile. It really makes a difference when you are out on the fringes.
Unfortunately we are legally limited to only 50 watts out on 440 in this
part of the world. Most of today's VHF mobile antennas are only rated
to 200 watts. Actually my base station VHF verticals are only rated to
200 watts. On 6-meters you are really antenna limited where a 1/4 wave
whip is going to be slapping a lot of overhead *stuff*
"I don't think" there's any thing in the cars that will be directly
affected by a 50 MHz signal, but from sheer strength and rectification
it could do all sorts of things. OTOH I'm not at all familiar with what
cars you have "over there" but I understand the big cars are quite popular.
I believe many of the newer cars are tested to 100W, but that's only 3db
difference and I'm not sure if the hybrids are tested at all. They do
not recommend direct connection and high current draw from the tiny
battery used for the engine and it's pretty much impractical to use the
"big battery". The tiny alternators are pretty anemic for charging a
hefty battery to run a couple hundred watts let alone the 800 plus watts
for 500 out.
BTW there are cars out there that have a very strong signal of 147.00.
Strong enough to over ride a 100 watt repeater a bit less than 2 miles
away when they are almost a city block away. As our repeater is 147.00
it eliminated me purchasing one of those cars, but it gave me a good
excuse to purchase a Trans Am with the Corvette engine<:-)) My mileage
may have not been quite as good, but the car was a lot more fun until a
SUV shortened it up by several feet. I said I was going to keep that
one until the wheels fell off, but I didn't think they really would.<:-))
73
Roger (K8RI)
> Take care...
>
> Regards.
>
> Dave G0WBX.
>
>
>
> ------- Original Message -------
> From: "Hsu"<hsu4qro@gmail.com>
> Subject: [Amps] RD100HHF1 work in 6m
>
> .
> .
> .
>
> PS, sometimes, If I run my SG500, my Golf's engine will stop, not often
> like this. Is is it due to the battery's problem?
>
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