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#3456 - 24/11/1999 07:48 Possible solution to noise pickup?
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Rather a lot of people seem to have encountered noise of varying types and degree following the installation of the empeg in their cars. Given that the unit is really well shielded, this is puzzling.

Following my install, I had no problems with noise of any kind, with the exception of noise when I used a CB in the car; this was eventually tracked to a duff CB.

A long time back I encountered a minor problem that caused the empeg to pause if the case was touched. Hugo's recommended solution was to crack off the facia screws by about a 1/4 turn. This I duly did. I got no repeat of the problem.

In the last couple of weeks I started to get engine-speed related noise breaking in apparently at random; this was annoying given that the installation had otherwise been perfect to date. This weekend I decided to check through the wiring of the installation to see if anything had come loose, such as an intermittent earth. After ripping out the dashboard (again) and checking everything, I was pretty puzzled to find very little was amiss, and that there was no obvious source to the problem. After putting it all back together, I took it out for a run, and was pretty annoyed when the break-in occurred again. Obviously, there was still a problem.

When I stopped to go back into the house and think it over, I missed the buttons in the dark trying to turn it off and touched the front panel. It wobbled under my fingertip! Agghh. Into the house, out came the loupe and the jeweller's screwdriver set, and I could see the panel could move quite freely around the screws. I gently tightened them, to find that they had rotated loose about 1 whole turn. The panel stopped moving.

I didn't try it that evening, but next morning drove off to work with emma blaring. I was about halfway to work before it dawned on me that there had been no noise break-in; in fact, I have had no repetition of the problem since.

So is this a possible source of all the reported noise problems - a lose facia allowing a break in the unit shielding which then causes pickup? To check this, I really need to loosen off the front plate again and see if it re-appears; however, bear in mind that after going through all my wiring and finding no problem, the noise break-in still happened and only when I tightened the front panel did it not repeat, after two weeks of frequent occurences.

I'll experiment a bit more and let you know.

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One of the few remaining Mk1 owners... #00015

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#3457 - 25/11/1999 07:26 Re: Possible solution to noise pickup? [Re: schofiel]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
This is repeatable. I loosened the panel screws off again last night, drove in this morning, and Bingo! noise break-ins started happening again. So, one more ride back tonight with tightened screws....

_________________________
One of the few remaining Mk1 owners... #00015

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#3458 - 25/11/1999 08:46 alternator blues (and how it was fixed) [Re: schofiel]
dionysus
veteran

Registered: 16/06/1999
Posts: 1222
Loc: San Francisco, CA
ok - here's what I ended up having to do in my car (...I can barely hear the alternator noise now w/ the player paused..)

seperate ground wire - ended up running another cable from the amp's ground, to the negative on the headunit.. also hooked up this same ground to the rca leads provided (only on the headunit..) - shielded this ground from reaching the amp using a groundlook isolator..
ALSO had to hook up this negative at the headunit to the CHASIS near the headunit.. (why??? this got rid of 90% of the noise, and the ground-loop isolator got rid of the other 10%)

I'm not even sure why it worked, but it's playing beautifully now w/o hardly any alternator whine

...proud to have one of the first Mark I units
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http://mvgals.net - clublife, revisited.

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