OT:Radio Interferance

Sep 24, 2004 77 Replies

"Shrek" wrote | I have a wireless network(802.11b), DECT phone and wireless doorbell | (due to hearing problems) all become un-useable evenings and weekends | when he is using the rig. | I had major problems with a wired alarm system late last year, the | manufacturers said the problems were characteristic whith *very* high | levels of RF, at the time I thought that was bull, but I my have done | them an injustice.

There are reports that Edinburgh taxis can't restart their engines if they're parked outside police stations because of interference from the new police radio network. And they're not allowed to park with the engine running because the wardens fine them[1]. They have to be towed away from the police station before they can start their engines.

Owain

[1] Anti-pollution rules in the Construction and Use Regulations.

G0JYO here, though not active for over 10 years !!

I dunno. I prefer 2LO myself.

.andy

To email, substitute .nospam with .gl

In article , Owain writes

I find that a tad difficult to believe;!. Haven't seen any evidence of vehicle malfunction by radio emissions for a long time now.....

Not sure re this specific case (I've not heard of it) but similar cases abound- especially to do with remote alarms / immobilisers. Cause is (at least) two fold- the frequency allocations for the 'fobs' is smack in the middle of a band used by others (not just radio amateurs- we share it with the Military), and poor design on the part of the car makers.

Having said that, just the appearance of an antenna can cause a rise in complaints that are totally unrelated. "East Enders" has been fuzzy for years (a blessing really), TV owner spots a new antenna, assumes it has been there a while and is the cause, radio amateur gets the blame. One of the first things I tell newcomers to the hobby - even before they get their licence- is get the antenna up but don't fit the plug at the radio end. When complaints come, show the neighbour that the thing isn't even able to be used.

Most definitely. If the guy is an amateur he should be helping. Either way, our leaving Shrek with a problem does the public image of the hobby no good.

Yes but some of this has now disappeared with the shutdown of the Dolphin TETRA network. Airwave of course is further down the band...

And its *still* a major cause of the cat having kittens;)

Is 'a long time' greater than 9 months?

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Yes, the motor industry is one place where EMC issues have been taken very seriously -

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- at least so far as safety critical stuff is concerned.

One exception though might be radio controlled central locking systems - I remember reports of people being unable to unlock their cars after the Dolphin network opened up on 420-430 MHz, when the keys were still using the old 418 MHz frequency with wide-open super-regen receivers.

Now the keys have migrated to 433.92 MHz these systems must still be susceptible to high-power 70 cm amateur transmissions, but the receivers have got quite a bit better, I think, with SAW filters on their inputs. Whoever was responsible for choosing that frequency for pan-European licence exempt telecommand stuff didn't really have their feet on the ground, IMHO.

that we've had any problems for some 5 or so years now. Prior to that time we did have some weird ones but since the EMC regulations and requirements etc no, none at all!.

Seems like this hasn't percolated over to Japan by the look of it!..

Might be a poor ground plane or high VSWR connections. In any case other local radio amateurs should be willing to help out or lean on him a bit.

cheers, Pete.

Err, me too, I'm afraid. G0CNR.

The only report of interference I ever got was one Sunday afternoon when a guy a few doors down came stamping up the road because I was interfering with his telly (There was a 17-ele for 144MHz and a 5/8 vertical for 28MHz on the roof of the house.)

Unfortunately for him, I was up a ladder painting window frames and not on the air at the time.

A few minutes investigation revealed a hooj CB aerial in an adjacent road, I gave him a copy of the booklet on interference and he went away, never to be seen again.

My 70cm handheld would crash the engine management in my Cossie if operated inside the vehicle.

"tony sayer" wrote | >There are reports that Edinburgh taxis can't restart their engines | >if they're parked outside police stations because of interference | >from the new police radio network. | I find that a tad difficult to believe;!. Haven't seen any evidence of | vehicle malfunction by radio emissions for a long time now.....

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radio system disables black taxis A NEW police radio system is leaving hundreds of city taxi drivers stranded - by stalling their engines. ... Masts at the police headquarters at Fettes and outside a cab office on Murrayburn Road are said to be blocking the signals which switch off the immobiliser. Drivers who park in these areas, which include a taxi rank near Fettes, are unable to start their engines again because of the interference. The only way to solve the problem is to tow the vehicles away from the masts so the driver can again turn off the immobiliser.

Owain

Have you visited the uk.radio.amateur news group these days? A snake pit would be a better place to visit. Less venom and more help :-)

Dave

(G6KHP)

Evening Brian :-)

Oh, it always was much like that.

Another one, the uk.d-i-y regulars will think this is a take over!

Either way, Shrek hasn't been back. Pity, it would be good to try and sort out his problem.

In article , Owain writes

Well they way that was originally written make it look like the engine management system couldn't re-start because of radio emissions not the bl**dy immobiliser!...

Wonder how the bobbies get on at Cambridge police station?. An Airwave system lives on the roof of the police station, and the Fire station next door. Perhaps they don't lock their cars;) or have taxis there..

I bet there has been one or two instances and its been blown up out of all proportion. Cabbies are like that....

It's probably all caused by his highly modified, souped up....washing machine!

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