Radoi interference

[Barry Montague]

Hi all
i have developed a problem with (yes i know) a silva s10
i am getting this with the engine running + when trimming
is it just the case of a supressor or will i need to look elsewhere
all ideas and help will be apreciated
Barry

[Biggles]

Barry,

I've got exactly the same problem.

Its been recomended to me to fit a supressor on the Radio Power lead. I shal purchase one from Halfords tomorrow and fit it at the weekend.

Its also possible to fit the suprressors on the spark plug leads but some web sites say this can damage the engine. So i shan't be doing that.

Let me know if you have any luck and I'll do th same for you.

Regards Nick R.

[nik]

I think supressors may be fitted to the lt (low tension) side of the coil, but not to the spark plug leads (HT).
As an aside, I was on a boat with a yamaha o/b and it caused terrible interference on the radio. Then after a while it stopped. Electronic engine management maybe?
Nick.

[Swifty]

Sounds like it might be easier to replace the crap radio

Tim'mers

[Barry Montague]

Hi Swifty
yep carn't agree more but the brass is short
surley you fit things to sort out interfeerence rather than replace
things in your job

[Swifty]

Originally Posted by Barry Montague

Hi Swifty
yep carn't agree more but the brass is short
surley you fit things to sort out interfeerence rather than replace
things in your job

I understand your point. Generally in my industry we cannot afford to do cheap bodges as potentially alot of people will see the problem.

But as regards filters, I have found its better to cure the Interference at its source rather than cure it at the problem point, although this is not allways possible. If it is a power supply Interference then it will be strait forward to make a filter.

Tim'mers.

[Scary Des]

Originally Posted by Swifty

..... If it is a power supply Interference then it will be strait forward to make a filter.

Tim'mers.

Does it have to be a specific design or is a there general rule? Des

[Swifty]

Originally Posted by Scary Des

Does it have to be a specific design or is a there general rule? Des

Bit of both!

The typical frequencies you are trying to remove are varying (idle to WOT) so an AC blocking circuit with a capacity of around 5 Amps is required. Simplest design is a large inductor in series to the positive. Quite often on car radios they have a plastic 'thing' in the power lead near to an inline fuse. I would try one of them first. It is a fairly hefty inductor inside.

PS.
A quick rumage in my bits and bobs box revealed a 220uH 3.5A and a 100uH 5.4A coil. You are welcome to try these out. PM me with an address.

Tim'mers.

[Biggles]

I bought an interference suppressor from Halfords today for £7.95 and will fit it at the weekend and see how it goes.

If it doesn't work they can have it back.

[Hightower]

Had a similar problem with my S10 after an engine refit, dam squelch wouldn't work whilst outboard was running. All I did was to move the coax away from the power lines a bit, not much but if you bunch up your cables into engine and everything else bunches I think you also will get good results like I did.

Good luck,

Andy