[TowerTalk] noise

Tue, 26 Aug 1997 12:03:29 -0400

Hi Mike,

Here's a critique of what you've done so far......

At 02:34 PM 8/26/97 +0000, you wrote:
>I've looked at night, no visiable arcing

This isn't definitive. You can't always see it.

>The radio is grounded to the frame at the radio (IC-706)

Since you can hear the noise on a radio next to your vehicle...
grounding isn't your problem.

>The DC power lead is NOT shielded

Probably wouldn't help anyway.  If you remove the antenna on your
IC-706 and grounded the input and you THEN heard the noise also... I'd
suspect the powerline as a source... but not in your case.

>The noise can be heard by another ham parked near me (at the moment, this
>precludes the power lead idea)

Correct!  What's happening is that some part of your ignition system is
BROADCASTING  a spark gap signal. That's what you want to find!

>When travelling under a bridge and listening to a AM station, the
ignition
>noise can be heard.

That's entirely normal. The AM signal is attenuated by the
superstructure and the radio's  AGC is running wide open.  The only
thing left to detect is the spark arcing.

>(I haven't done the AM radio sniffing yet, but the signal is so loud it
>might be difficult to attenuate)

Difficult Yes!  Impossible... NO!  First.... try with a station tuned
in.  This helps immensely (signal to noise ratio and all that).  Next,
try shielding the radio by wrapping it in aluminum foil and possibly
even running a wire from the aluminum foil to chassis ground. That
should do it! Move the radio around until the noise gets loudest. 

>Options so far (and I have thought of all these):
>
>Turn the car off when talking (makes for long trips)

THIS IS ONLY NECESSARY WHEN GOING DOWNHILL!

>Sell the car (not to a ham) 

Offer the STATIC as a NOSTALGIC CLASSIC FEATURE FROM YESTERYEAR!
REMEMBER... WHEN LUCK GIVES YOU LEAMONS... MAKE LEMONADE!

>Forget HF mobiling (not an option)

ONLY UNTIL THE SUNSPOTS PICK UP!

>Take up spark gap mobile

EDMUND SCIENTIFIC SELLS SOME GREAT Tesla Coils.

>The funny thing is this only happens to 1988 Honda Civics (the only Honda
>with the Black Bumper).  

TRY PAINTING THE BUMPER SILVER? ;-))

>If I am in the other car with HF and drive near
>another 1988 Honda Civic DX, the ignition noise is heard.  

THUMB TACKS AND NAILS AS CHAFF "ACCIDENTLY" SPILLED ON THE ROAD LIMITS
HIS NOISE PRODUCING RANGE.

Also, a small crack in your fuel line and a spray of gasoline on the
hot engine will bring you a quick insurance settlement for a new
vehicle. Trying to put out a gasoline fire with pails of water has
interesting consequences worth investigating. Vehicles undergoing
"incendiary purging of ignition noise" have also been known to do nasty
things to asphalt driveways. Better to choose to locate the vehicle
over a mole tunnel or perhaps a large patch of crabgrass.

88 Honda Civics are also susceptable to drifting away on air
currents... especially when eight or ten helium filled weather balloons
are tied to their bumpers while parked along some coastline beach
during an off-shore breeze. Many Balkan countries import vehicles in
this manner.

Good luck with your noise hunting!

Roger, K2JAS..... "Just Another Sparkhunter"

內躬偕爻,虜,齯滌`偕爻內躬偕爻,虜,齯滌`偕爻齯滌`偕爻,虜,齯滌`偕爻內躬偕爻

>Many thanks so far....mike
>
>73
>
>At 10:12 AM 8/26/97 -0400, you wrote:
>>Hi Dick,
>>
>>re ignition noise and finding shielded distributor caps etc....
>>
>>My best guess is to look in a J.C. Whitney  automotive parts catalog.
>>Perhaps they even have a web site. I haven't looked in one of those
>>automotive catalogs since I was a kid foolin' with hot rods. Any big
>>newsstand or Barns and Noble Bookstores should have them. 
>>
>>I would also imagine that in a real pinch you could fashion something
>>out of aluminum foil.... say the real heavy duty stuff used for
>>baking.... and double or triple layer it.  
>>
>>If you can put your hand on the distributor cap or any of the ignition
>>wiring and get a nice HV jolt.... you probably have an insulation
>>breakdown problem.  Since the spark is arcing where it shouldn't- THAT
>>is what's causing the majority of your ignition noise! Ignition noise
>>from high voltage arcing is typically heard on your radio's receiver to
>>change in frequency as you vary the engine speed.
>>
>>Another trick we use to locate the source of the sparking - is to park
>>the car in the garage at night and run the engine - with the garage
>>doors open - of course - and all the lights off. When your eyes have
>>become dark adapted... lean into the engine compartment and look for
>>the blue sparks of ignition arcing and listen for the characteristic
>>loud snapping sound... which to the trained ear is different than the
>>sound of noisy valve lifters.  
>>
>>It's also a good idea when doing this to not wear loose clothing like
>>ties and bolo's.  You wouldn't want to get wrapped up in an engine belt
>>in the dark... would you?  (THIS... is a wonderful seed of an idea for
>>one of K4IBP, Jack Goforth's humorous stories. I'd do one myself....
>>but I promised I wouldn't!)
>>
>>Hope some of this has been of help.
>>
>>Roger, K2JAS.... "Jealous About Sparking"
>>
>>內躬偕爻,虜,齯滌`偕爻內躬偕爻,虜,齯滌`偕爻齯滌`偕爻,虜,齯滌`偕爻內躬偕爻
>>
>>At 04:21 AM 8/26/97 +0000, you wrote:
>>>>If you have noisy ignition cabling.... there are shielded ignition
>>>>wiring kits.  If you have a noisy distributor cap.... there are
>>>>shielded caps you can buy.
>>>
>>>Shielded distributor caps?!  Ooooh, I would love to find one of those!
>>>Where would I look?
>>>
>>>73, Dick
>>>
>>>--
>>>Dick Flanagan W6OLD CFII Minden, Nevada
>>>Visit http://www.delphi.com/electronic/
>>
>>
>>--
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>>
>----------------------------------------------------------------
>Michael K. Walker                   Legato Systems (Canada) Inc.
>Escalation Managment                     3390 South Service Road
>(905) 637-4738                                    Burlington, ON
>http://www.legato.com                                    L7N 3J5
>pager:  1480111@pagemart.net
>

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