Outer Limits 4x4 Board

Hello all.

I run radio gear (HF, VHF and UHF) in my Zook (1.3L carb), and I am currently trying to reduce the amount of spark noise that the zooks spark/ign system is generating.

I have just done the 100A Falcon alternator upgrade, and since then, the problem has gotten worse (it was just 'bearable' before, but now its a struggle to use the radio gear with the engine running.) I attribute this to the fact that I now have a very healthy electrical system, and I hence now have a lot more spark energy - of which a lot more is now being 'radiated'.

During the alternator upgrade I changed the alternator, battery and alt charge cable. I did not touch anything else. I MUST STRESS that this is NOT alternator noise. IT IS SPARK NOISE. Also - there is nothing wrong with my radio gear / antennas or installation (trust me on that - I have access to radio test equipment worth more than all of our zooks combined).

In order to try and reduce/eliminate the noise, I have:

* tried many different earthing points / earthed out panels (using copper earth straps), earthed exhaust, chassis to block etc etc...
* replaced dizzy cap, leads (top gun), plugs and rotor.
* added coil suppressor/condenser (0.5uF)
* I isolated the radios from the zooks power source, and ran the radios to an independent battery source. The noise was still there - this proves that the noise is being radiated, and is NOT coming down the power cables.

None of these usual 'process of elimination' methods have had any impact at all. Usually, some improvement can be found, but there is none! So my questions are these:

1) Has anyone here won this battle with a zook before? If so, what did you do??? (ie- NEW dizzy etc..)

2) Is this amount of spark noise common on zooks? (NOTE- it is noticeable on UHF, but is much worse the lower in frequency you go. ie - worse on VHF and HF)

If anyone has had any experiance with the problem IN A ZOOK then please feel free to make a suggestion! (I don't mean to be rude but I am not interested in what fixed your mates Commodore etc etc... That is just not going to help me )

Cheers all,

Pez

Try some stock leads back in it?

Steve.

now i'll start by saying that i have come across this but not in a zook, but i have a fair bit of electronic knowledge (electrical enginnering)

im thinking that you may have a problem with the radio gear and not the coil as you have isolated the vehicle from the radio gear and the noise ahs not gone away, theres a lot of factors that could cause this like inadaquite sheilding of the radio the coax cable is running parallell with current carrying wires or the antennas freq range is within the same freq range as the ignition causing the static,

i had this when i experimented with a free antenna i picked up which was 4 metres long, i was under the assumption that the longer the antenna the more signal i would have well its true if i wanted to pick up low freq but all sorts of interference would come through the speaker, i then binned the antenna went back to my old one and jacked up the signal strength and cleaned up the S/N ratio

im just sugesting my opinion as a electrical engineer so don't get your knickers in a knot if i cant help you

Steve - I tried that too - same result!

Wrench_Pilot_86 - my knickers are fine mate haha - I am also in electronic engineering, and I specialise in RF, so I understand exactly what you are trying to say... My antennas are resonant where they need to be, my coax is extremely low loss and very well shielded - and all run as far away from other wiring as possible. Everything is commercial grade (no dick smith connectors here).. (I'm not being a smart arse - but I really did mean it when i said that you should trust me on that one!)

The radiated noise from the zook is very broadband (can hear it from 3-500MHz at least). As a side note, I can hear it on a hand held radio standing next to the car (thus eliminating the radio equipment as the problem) - it is being radiated from the car -but from exactly where is the question!

Cheers

Pez

have you tried one of those whatchamcallits that you wire into the coil. theyre supposed to work.
what sort of leads did you get, i bieleve the top gun 7mm spiral wire leads help to reduce this.

Any corona discharge at night, that would look cool (like the car from Wraith)

how a about a really big faraday cage?

just don't feed the faradays.

seriously though here is somting i found online some of which you have already covered.

Make sure you've completely installed your CB and the antenna is grounded properly. Check the amount of noise with and without the antenna connected. If the noise is greater when the antenna is connected, the source is probably the ignition system. If the noise remains unchanged after disconnecting the antenna, the source is probably in the CB's power supply.
For ignition noise, there are several parts of the vehicle that can act like RF noise transmitters if not properly grounded. Check (and connect to ground on the chassis/frame, if necessary) the engine block, hood, muffler, and exhaust pipe.
Ignition noise can be further reduced by installing "magnetic suppression" spark plug cables. (These are significantly more expensive than normal spark plug cables.) For power supply noise, check if you have a capacitor attached to your ignition coil, alternator, and distributor. These can act as filters right at the source of the noise.
Ensure that your antenna feedline and power lines are as far as possible from any of the noise sources mentioned above, especially the engine block.
A shielded power cable can help as well. Make sure it is of sufficient guage to handle your radio's power consumption and that the shielding has a good, strong connection to ground on the vehicle chassis or frame


note: I'm not an electrical engineer, but i am really good a internet research.

Hope it helps

Edit: this might be useful if you can understand it (I had a stroke at the first equation)

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=12692

I know it seems to be a spark noise, but it all just seems to be point to the alternator(as its virtually the only thing u added). Just a suggestion what happens when unplug the alternator? RF noise get better or worse?
Does it increase with rpm or stay constant?

Dan

Have you tried resisted leads and resisted plugs?

Instead of of running BP5ES's try BPR5ES or BPZ5ES

Theese are both resited plugs and may help.


Mike

Hi Guys.

crackatinny - Is it Tuesday???

PCRman - I have already covered every point in your 'red' text with no success. Those steps usually have some effect on reducing radiated noise, but unfortunately for me, its just not happening in the zook (and hence the reason for me starting this topic in the first place). The DXZone link contains some very good information. I understand the theory - most of it I have already applied to the zook with no success. Making up some braided lead covers might be an option too, but it's a last resort at this stage...

JrZook - It IS radiated spark noise. Full Stop. The alt is not causing the fault. With the alternator removed from circuit, the problem still exists.

Mike_1324 - That is a good point regarding the plugs. I think I will give some resistive plugs a go - I am running standard BP5ES. Its definitely worth a shot!


Another thing I might do is replace the original coil (it is the original 1991 coil as far as I can tell). You just never know...

Cheers

Pez

I fitted MSD ignition to my Falcon ute and got heaps of electrical noise through the stereo.
No amount of suppressors would fix it so I spoke to the tech guys at MSD and they suggested a shielded cable from 7AL2 box to the distributor.
Problem Solved.

Hey Pez i feel for ya, i know what it's like. I had the same issue the other day at work but it ended up being the electric thermo fan.

In my zook i run VHF and UHF and have no issues at all.
I run nothing different in the ignition system except a after market high spark coil.

If you need a hand or any other test equipment that i may have let me know.

but besides that i am stumped, you have done every thing i would have done, i am guessing you have run some RG-223 or 9006 coax or similar?

All i can think of is putting an ferite choke somewhere or maybe everywhere or maybe even on the ignition leads. i know this normally goes on the power cable but maybe put one on the lead between the coil and the dizzy, but this is only a guess as i have no idea.

also might have to get the IFR out and sniff for it??? I know this works with intermods but no idea if it will work with spark.

Cheers
Simon..

Hi Simon.

Yeah mate I am scratching my head I can tell you! The IFR / Spec analiser is no help in this case as the noise its very wideband (DC to 500MHz roughly). It does confirm that it IS radiated noise however.

I tried the BPR5ES resistive plugs yesterday but that made no difference either. I even bypassed all of the zooks wiring (all looms / tacho / the lot!) and ran my own temporary ignition circuit using shielded cables - still the same! Using ferrites would be an interesting test, however I am now fairly confident that the leads are not the problem... FYI- Coax is RG-58 Cellfoil solid core (9006). Very good stuff!

Tomorrow I am going to try another coil and see how that goes. Wish me luck! (I'm clutching at straws now!)

Cheers,

Pez

Is it as bad with the antennas on and off????

just trying to elimate the install! Which i know would be purfect.

Once again i have no idea, maybe try these clip on ferrite things might help.

You should be out there now putting the coil in.

Simon....

i get the same in my zook with the radio and the UHF. the noise goes up with the revs and its realy annoying. how can i fix it?

sorr to hijack

Yeah it's not as bad with the antennas off - it is airborne noise!

I don't think I need to worry about the leads too much - I have tried a couple of different sets and the result is always the same...


brendan_hh - stay tuned - if you have tried all of the things listed in this post so far and are still having no luck, then we are in the same boat

Stay Tuned!

Pez

what should i try first? see if eveything is grounded right?

If you read the first post all the info is in there.

BUT i would start at the EARTHING.

Simon...

Pezooki you say all the stuff is commercial top grade stuff, but they do still fail. I would be personally looking at the things you are overlooking. If the noise has been getting worse with the new alternator I would be addressing that as well as your spark noise. A combination of noise from your alt and ign could be your issue.

A lot of people have done the alt coversion and use uhf/am cb's and don't encounter a problem.

I lose count of how many things don't work correctly because I took things for granted.

I'm not an expert but its just a thought.
Eff

not the best idea but disconect the alt once running as a test for noise. see if there or not once unplugged.

Ok everyone...

I have proven that the noise has NOTHING to do with the alternator, my radios, or my installation etc... YES my gear is commercial 'top grade' stuff - which like anything can fail - but the difference here is that I have access to commercial test equipment - and I know how to use it!!!

For anyone who is still thinking that my radio installation is the problem here, please consider this: - If you park YOUR car next to mine (within 10M of it), YOUR radios WILL experience the same problem that I am experiencing. It is radiated noise - it will affect any HF, VHF or UHF radio gear within 10m of it - IT IS RADIATED SPARK NOISE.

For anyone who still thinks it might be related to my alternator : -you can use a timing light and align the flash of the timing light to the noise. Removing the alternator from circuit has no effect on this.

I really do appreciate the feedback guys, and I don't mean to sound like a tool (sorry if I do ) ... I did start at the beginning with this fault, I spent hours on it before I posted this topic. Nothing has been taken for granted. I have solved this problem on other cars more times than I can remember (I am in the business) and have never had such a hard time finding the source of the noise - hence why I asked the question SPECIFICALLY in relation to ZOOKS, just in case someone had the problem in a ZOOK in the past...

Obviously, my spark noise problem is NOT a common Zook problem.

Today I tried a new coil too - it made no difference. That leaves the distributor as the ONLY item in the ignition system that I have not isolated OR replaced. (Dizzy has a new rotor and cap). I am heading away next weekend so I will leave it alone for now. When I get back I will pull it down, inspect the internal modules, clean it up and see how that goes...

I will keep you all posted.

Cheers,

Pez

Are you running resistively or inductively suppressed HT leads ?

If there resistive they may have deteriorated over time ( the carbon impregnation of the fibreglass cords settles out ) leaving an array of micro spark gaps...

That's why good quality suppressed leads are inductively wound.

luck with the problem......

Pezooki wrote: : -you can use a timing light and align the flash of the timing light to the noise.

Purely for my own interest, if you can align the noise to timing light flashes, doesn't that mean that it is the current to a single cylinder causing the noise?

Hi MightyMouse.

Yep I am running brand new inductively wound leads. The old ones (which I don't think were that old) were also inductive leads. I have pretty much ruled the HT leads out as the source of the noise.

I was having a read through a previous post of yours (I think it was yours) regarding a module swap using an I6 Commodore Bosch module and coil. That sounds like a good thing - and just 'maybe' could be a way for me to remove another peice of this puzzle...

Cheers,

Pez

PCRman:

I probably should have made that a bit clearer... It is in sync with the main coil to dizzy lead - that is, every time the ignition fires, regardless of the cylinder, I hear it...

Pez

Cheers for the clarification. I'm learning a lot from this thread, which may come in handy when i get around to a alt upgrade and some radio equipment.

is the noise u are hearing on the radio when u speak(as in other party hears it ) or on receive end?

i have the first issue in mine, and was going to try noise choke/filter on the power cords to see how it goes.

didnt have the issue in old zook(carby) but new zook has issue (efi 16v)

radio is the same gme4200, was going to try the standard or TAIT in there but not got round to it.

PCRMan: It's all good!

Yep there is a lot of very good info in here - Up to this point, if all of the above steps are followed, I would think that 99.99999998% of vehicles with spark noise problems would be all sorted out...
I hope for you that your car is one of the 99.9999998%!




Nicbeer: The problem is only on RX for me.

If you have noise on your TX then it is almost certainly noise on the power supply. The best thing for you to try would be to get a spare battery and sit it on your passenger seat. Remove all zook power from your radio and connect it directly to the independent battery on your passenger seat. If the problem goes away then the problem is with your power supply in the zook. You can try power filters, OR (if applicable) move your radios earth point off the zook battery and put it to a good chassis/body earth point (closer to the radio is better than a long run of cable too.)

If the noise is still there, re-route the coax as far away from ignition sources/other looms as possible. If the problem still exists, replace coax / have someone check antennas etc etc... While the Tait and Vertex Standard are much better radios than the GME, if your power is dirty then they wont like it either!

Good luck!

Cheers,

Pez