AIS and PC interfering with my VHF

[BlueChip]

I've got an Icom M601 VHF, built in HP micro PC and Matsutec AIS and I'm finding that when I power up either the PC or AIS I get a lot of noise on the VHF.
I have to turn up the squelch to a high level to get rid of it, this means that I miss all but the strongest transmissions.
The PC and AIS are both fitted within about 30cm of the VHF, the AIS comes off the same power distribution board as the VHF but the PC is powered by a 240V inverter

The VHF has been back to Icom for a service and software update and works perfectly when nothing else is on.

Can anyone suggest what to try?

 

[MikeCC]

Do the cables for various kit have ferrites installed on them? Possibly as supplied with original equipment but available separately.

 

[Yngmar]

Is there a USB-serial converter between the PC and the AIS? Try unplugging it (from both) and see if the noise stops. If it does, replace or shield it.

 

[BlueChip]

Do the cables for various kit have ferrites installed on them? Possibly as supplied with original equipment but available separately.

No there aren't any ferrites..
I've ordered some up, would I fit them on just the power cables or on signal cables too?

 

[BlueChip]

Is there a USB-serial converter between the PC and the AIS? Try unplugging it (from both) and see if the noise stops. If it does, replace or shield it.

There is, I've disconnected that and it didn't make any difference.

 

[BlueChip]

The ferrite core sleeves I ordered from Banggood.com had arrived when I got home.
Which wires shall I fit them too?

 

[MM5AHO]

Fit ferrites to first powder cables, then to signal cables if still noisy. Try not just fitting, but if the cable small enough and ferrite big enough take 2-3 turns of cable through. If you can't, then once through will still help.

 

[BlueChip]

Fit ferrites to first powder cables, then to signal cables if still noisy. Try not just fitting, but if the cable small enough and ferrite big enough take 2-3 turns of cable through. If you can't, then once through will still help.

The ones I've got are ferrite sleeves, but I've just ordered some rings in case the sleeves don't work.
Is it possible to have too many ferrites on the cables, or shall I just fit them all.

 

[BlueChip]

Just a follow up, I fitted bullet ferrites that I bought for just a few pounds from Banggood and that solved the problem.
Thanks to all for the advice.