HF Radio Interference on 14MY D4

[Boggs]

I have just installed a Codan 9323 with autotune into my D4 from another vehicle, a 2001 Troopy. The radio was working perfectly in the previous vehicle but now experiences such bad interference that it is unusable. This is a loud, even and constant "buzz" interference and happens even with engine off. I have installed several HFs before and think I know what I'm doing, though this is the first high tech. vehicle I have done this on. Have covered all the bases such as good earth on antenna and unit. Power is supplied by the auxiliary battery and routed to avoid any conflicts with other wiring according to Codan guidelines. The fact it occurs with engine shut down has me baffled. With engine running there is no difference or change with engine revs. Could it be the proximity key used on the 14MY? Any ideas?

[Tombie]

Is the buzz at about 6 "buzzes" per second?
If so, it's picking up the can-bus pulse.

[Boggs]

Hard to say.. more like a chainsaw running at constantly just above idle. What's a can-bus?

[goingbush]

Have you
put RF earth strap from chassis to body and body to bonnet ?
is your fridge running ,
installed ferrite suppressors on fridge and radio cables??
twisted radio power and speaker cables to stop induction ??

disconnect car battery / isolator to see if buzzing stops

[Boggs]

Have you
put RF earth strap from chassis to body and body to bonnet ? Not sure where the bonnet comes in here, Antenna is on swing away and antenna earth strap direct to chassis, ditto earth strap from radio main unit to chassis also.
is your fridge running , Fridge not running, anyway Engel compressors generally do not cause interference unlike some others brands that use Danfoss comps.
have installed ferrite suppressors on fridge and radio cables?? Already have a ferrite suppressor on the radio +ve power run, non on fridge but not required as above.
twisted radio power and speaker cables to stop induction ?? Speaker cables run nowhere near power cable

disconnect car battery / isolator to see if buzzing stops A good point, I'll run from an independent 12v source and check, if interference still there then that will discount any power issues

[Graeme]

Does the interference stop after about 30 seconds after the engine is switched off?

[Boggs]

Interference is there all the time.. does not change with engine on or off, even after engine shut down for hours.

[Graeme]

I suggest disconnecting the earth lead from the battery isolator as its easy to do and therefore check if the isolator is the cause.

[p38arover]

I fitted the 9323/9350 to my P38A last week to test it before selling the radio. When I sent a Beacon call, the RF shut down the P38A's engine. I tried it several times.

I had been warned by another bloke that it might happen. (The radio was connected to the second battery.)

[Tombie]

Interference is there all the time.. does not change with engine on or off, even after engine shut down for hours.

Close car but leave window open so you can access radio to check...

When you open the door the vehicle 'wakes up' again so...

Using the window to gain access after about 30 min see if it is still buzzing.

[Boggs]

Just wondering if some sat phone manufacturer paid land rover to build them like that!