Barrett 950 & Engine Electrics issues??

The general thrust of the advice you received is true, in that TX on that radio (probably others as well) can spook the computer signals in many modern vehicles. I can TX voice on my 950 in my LC100 series GXL while mobile*, but I once sent a selcall while cruising and it killed the engine ! Had to coast and restart (scary - dangerous - not again). Technicians (I'm not one) suggest a meticulous installation that satisfies various protocols (shielding and earthing mainly, as I recall) can avoid these issues. I simply did a basic install and ensured that all relevant components were well earthed throughout - this setup suits my circumstances. Seeing the 950 is getting 'old' now, it may well be that the current generation HF's in the big brands might do a whole lot better.
*In-car circuit noises while mobile make both Rx and TX impractical for me a lot of the time; I just stop if I have to comm. with someone (many others do the same).

I am interested in this myself, as I am toying with the idea of updating both HF and vehicle at some stage.


.

I used to install HF's as a living and basically yes if the engine is running then the radio will be picking up lots of interference which can overload the receiver and in turn can also affect the engine electrics to the extent that as others have said it can stop the engine.
In some vehicles you can limit the extent to which they affect each other but to completely stop interference in both directions on a modern EFI vehicle is nigh on impossible or financially feasible.
Attention to earthing ALL panels, doors and bonnet, including the exhaust and all mechanical components including the diffs, gearbox and transfer case individually to the chassis and in turn the engine/battery ground by fitting individual braided tinned copper earth straps. To do this correctly you remove mounting bolts, remove all paint etc back to shiny metal and refit the bolt ensuring that the braid makes a good electrical contact.
Don't forget the bullbar and towbar either. Individual electrical items like instrument and warning light senders will all need individual suppressing and you will also need to somehow shield the injection wiring and ECU.
As most customers did not wish to outlay the much larger cost of an installation on EFI vehicles we used to advise that the radio would be virtually unusable whilst the engine and other accessories were running.
Even in our 1HZ powered troopy with all the above done the wife and I had a shutdown procedure if we ever received a selcall whilst travelling which culminated in being stopped on the side of the road with everything switched off including UHF CB and GPS. Basically anything with a CPU like all the things we have these days will cause interference.

It shouldn't and doesn't need to be an issue Bungarra.

You can have a lot of fun with that stuff , one of my setups can output around 400w and will make the indicators of nearby commodores blink faster or will simply overload nearby phones.

But my 950 does not do these things , they only run 125w peak - and I regularly check beacons while mobile using it without issue.

You just need to use good practices like running 4mm sq minimum + & - power cable direct to battery (6mm if more than a couple of meters) also have properly tuned antenna's.

I came across several bad setups over holidays - one spliced power into a high powered audio system to an unknown loom and it turned out that the load on TX was pulling down the +ve line to some electronics and causing some strange effects like shutting down the fridge.

The owners are working on getting 4000w of audio to work - and I sort of made a few comments , but wasn't anywhere near as helpful as I could have been, although I did re-wire the fridge for them.

.

Oh, blessed am I with a mechanically injected 1HZ Troopy and my Codan 9323.


Pass me that bit of fence wire, will you?

I'm very interested to hear what the RF immunity levels are like on modern vehicle electrics.

I can quite imagine that some of the manufacturers may not have consider high power transmission soo close to their electronics.

100 Watts of RF is quite a lot of schnaps.

I worked a rural show where we had some army boys where playing with tanks and APC's for the amusement of the public.
We had a bloke fire up on 50ish meg to the tune of 100watts meters away from our sound gear...of course our radio mics where useless, but I was not getting intrusion into the small signal audio cables lke we would get from the digital mobiles at the time.

Some of the sensors in the engine management and the ABS brakes will be running pretty small signals.....I would have thaught they should all be pretty solidly shielded and properly nailed down.

But then again some of the american vehicle electronics is dodgy at the best of times.

So you guys that work with HF all the time.
Tell me what is the extent of the problem and is it air borne or ground and power supply borne.

I'm just thinking about the implications for someone firing up on HF at 100+watts, right next to another vehicle on the highway that has electronic management systems.

Surely not???

cheers