Omega Owners Forum

Omega Help Area => Omega Electrical and Audio Help => Topic started by: ffcgary1 on 19 November 2011, 15:56:10

Title: RADIO SUPPRESION NOISE
Post by: ffcgary1 on 19 November 2011, 15:56:10
A few months ago i conversed with Dave DND about terrible interferance on the am band on my cdr500 radio in my omega estate, and it was generally thought that because modern cars have so much electrical gizmos it could be anything causing it,
The noise is only made if the wheels are turning and it stops as soon as the wheels cease to rotate, Now the only thing that i can conclude is that the noise is being made by the abs sensor, and i can't think it could be anything else, but you guys may tell me more.
Is there any way that i can suppress the noise and even where the suppresor should be fitted, or is this something that i will have to accept as unfixable, over to you guys, thank you in advance.

Gary.
Title: Re: RADIO SUPPRESION NOISE
Post by: Andy H on 19 November 2011, 16:48:53
The pulses from the abs sensors go to the ABS ECU. The ABS ECU amplifies these pulses to use for ABS & TC but also sends a 'speed pulse' to the speedometer, the trip computer and the radio.

Some radios allow automatic volume control and use the speed pulse to increase the volume.

Maybe the speed pulse could be the source somehow :-\
Title: Re: RADIO SUPPRESION NOISE
Post by: Dave DND on 19 November 2011, 16:56:24
Quote
The noise is only made if the wheels are turning and it stops as soon as the wheels cease to rotate, Now the only thing that i can conclude is that the noise is being made by the abs sensor, and i can't think it could be anything else, but you guys may tell me more

There are hundreds of things it could be, and my technical manual here has 17 pages dedicated to suppressing body panels alone, without even starting to go into the electronics !!

If you really want to track it down, then get yourself an interference "sniffer" they are around £150 and you can then spend the next six months trying to fix all the things you find.

Or you could take the advice I gave you on the phone and step away from Medium wave !!  Its Dead !!
Title: Re: RADIO SUPPRESION NOISE
Post by: ffcgary1 on 19 November 2011, 16:59:49
Is it poss to turn off the speed volume control on a cdr 500, if so it my cure the noise that i get trying to find out if fulham are losing again :D
Title: Re: RADIO SUPPRESION NOISE
Post by: ffcgary1 on 19 November 2011, 17:11:31
Hi Dave, yep havnt forgotten the advise you gave me, but me being a sad git means that i have to try to solve it, it gets under my skin that much it drives me to the brink of despair sometimes, i know what you mean by mw being dead but talksh** is only on MW ::)
Title: Re: RADIO SUPPRESION NOISE
Post by: Andy H on 19 November 2011, 17:12:35
Is it poss to turn off the speed volume control on a cdr 500, if so it my cure the noise that i get trying to find out if fulham are losing again :D
I don't think that changing the AVC setting would make much difference.

I was thinking more along the lines of the speed pulse being fed into the back of a radio that wasn't expecting it (is your radio original?) or perhaps wiring damage.

Have you ever been able to receive good AM reception?
Title: Re: RADIO SUPPRESION NOISE
Post by: Andy H on 19 November 2011, 17:16:16
Hi Dave, yep havnt forgotten the advise you gave me, but me being a sad git means that i have to try to solve it, it gets under my skin that much it drives me to the brink of despair sometimes, i know what you mean by mw being dead but talksh** is only on MW ::)
Talksport is on DAB. ;)

I'm not a fan of football so I don't tend to listen to it but it seems to be available everywhere I have been in the UK
Title: Re: RADIO SUPPRESION NOISE
Post by: ffcgary1 on 19 November 2011, 17:24:26
Hi Andy, no it is not the original as the original car 400 gave up the ghost, MW has never been great even on the original but never this bad, Is there a wire colour for the avc control or does it come through with other signals or wires.
Have been advised by dave to go the Dab/ Pure highway route so will have to bite the bullet maybe and do it but it rankles me no end.
PS
God i wish my old man had never taken me to fulham when i was young, but he said to me "SON, IF I HAVE HAD TO SUFFER FOR 40 YEARS SO CAN YOU!!!" ;D
Title: Re: RADIO SUPPRESION NOISE
Post by: Dave DND on 19 November 2011, 17:24:44
Suggest to invest in a PURE HIGHWAY DAB box, and run it through the FM of your existing radio - as all of the old AM stations are on there !!

 ;)
Title: Re: RADIO SUPPRESION NOISE
Post by: Dave DND on 19 November 2011, 17:27:40
And I know that you are determined to give it a go despite what is said here, but I am confident enough to wager a bet that you will NEVER cure the MW interference

 :-X
Title: Re: RADIO SUPPRESION NOISE
Post by: ffcgary1 on 19 November 2011, 17:33:42
I ONLY EVER BET A PENNY DAVE, AND AGAINST YOUR ADVISE I WONT RISK THAT MUCH. ;D
Title: Re: RADIO SUPPRESION NOISE
Post by: Dave DND on 19 November 2011, 17:38:34
I ONLY EVER BET A PENNY DAVE, AND AGAINST YOUR ADVISE I WONT RISK THAT MUCH. ;D

A penny bet ?

Sir, if I had a gauntlet, I would throw it down and challenge you over that penny then !!

 ;D
Title: Re: RADIO SUPPRESION NOISE
Post by: ffcgary1 on 19 November 2011, 17:43:48
Run away Run away !!!!!! :o
Title: Re: RADIO SUPPRESION NOISE
Post by: Andy H on 19 November 2011, 19:11:57
Hi Andy, no it is not the original as the original car 400 gave up the ghost, MW has never been great even on the original but never this bad, Is there a wire colour for the avc control or does it come through with other signals or wires.
Have been advised by dave to go the Dab/ Pure highway route so will have to bite the bullet maybe and do it but it rankles me no end.
PS
God i wish my old man had never taken me to fulham when i was young, but he said to me "SON, IF I HAVE HAD TO SUFFER FOR 40 YEARS SO CAN YOU!!!" ;D
OK. so original radio was CAR400. Current radio is CDR500. Has anyone got access to the pinouts for these two units? is the info on TIS perhaps?

According to the book of lies the speed pulse (WEG) is BLRT (Blue with Red stripe).
Title: Re: RADIO SUPPRESION NOISE
Post by: Dave DND on 20 November 2011, 09:35:55
Radio pinout should be on a label on the top of the radio - look for pin marked SDVC

Speed Dependant Volume Control

 :y