LEDs interfere with radio

[Top cat]

Geo

 

Thanks for the tip , I will investigate, I have some ferrites , have tried them round the radio power leads and the rear speaker leads to no effect. Will now try as you suggest.

 

J04n

 

According to the manual the moonraker is directional but in practice we very rarely need to bother ajusting it.

 

I've also found that the aerial lead sheath has a break somewhere. Its grounded via the radio chassis and it may be at the roof but there is no connection beteen the two.

 

Top Cat

Edited October 17, 2016 by Top cat

[WotEver]

I've also found that the aerial lead sheath has a break somewhere. Its grounded via the radio chassis and it may be at the roof but there is no connection beteen the two

Perhaps it has been correctly wired with a capacitor in the screen. If not, then this will likely be the cause of your problems.

[Geo]

Geo

 

Thanks for the tip , I will investigate, I have some ferrites , have tried them round the radio power leads and the rear speaker leads to no effect. Will now try as you suggest.

 

 

 

I would guess some 25mm to 30mm rings with both wires threaded through and wrapped round the core 3/4 times and the turns secured.

[Top cat]

I'm getting very confused by this job. I tried to connect to the Moonraker dtv aerial via a duplexer but my radio has a JASO connector. Having failed to find a Jaso to co-ax adaptor I bodged a short piece of wire between the two cables. Held ot all together and it seemed to work even with the lights on. Then it fell apart and continued to work with just the stub end of the wire sticking out of the JASO.

Now I've got a random length of wire curled in an untidy heap on the floor one end of which is attatched to the JASO connector and seem to be getting reasonable reception. Of course I wont really know till it gets dark or starts to rain.

It looks like I should replace the aerial lead but its inaccessible behind the panelling.

I've also been trying to track down LED s with low EMI the only ones I've seen are the expensive Bedazzled ones. Anyone know of a cheaper source?

 

Top Cat

[WotEver]

Ahh, you're discovering the wonders of RF reception...

 

You're not getting it when you want it and some kit gets it when it's not wanted... it's a black art.

[Geo]

Ahh, you're discovering the wonders of RF reception...

 

You're not getting it when you want it and some kit gets it when it's not wanted... it's a black art.

 

Something I have enjoyed for many years lol

[alias]

Anyone know of a cheaper source?

 

Top Cat

 

I've bought a few from this Chinese seller previously recommended on here, and no interference: http://www.miniinthebox.com/. One faulty one (didn't work at all) was replaced without questions, and with an apology, the only downside being the time it took to reach me from China!

[Top cat]

Thanks I'll go and have a look

 

T C

[ditchcrawler]

I'm not a great aerialist but rubber duck aerials normally have inherent attenuation - but don't require a ground plane. Aerials that require a ground plane can be accommodated by connecting the lead's screen to the hull, but by means of a small capacitor so that there is no DC path.

When ever I read this I do wonder of all the boats I see with rubber ducks have a capacitor in the lead. I keep meaning to get round to it.

[Top cat]

Here's an update on things I have tried, all unsuccessful

 

Ensuring aerial ground is properly connected to hull

Removing corrosion from aerial inner conductor joint

Powering radio from independent power supply

Adding ferrite rings to light leads

Moving rear speaker wires away from power wires

Twisting rear speaker leads

 

 

I've just about run out of ideas, the only thing I can think to try is adding 0.1 micro farad capacitors to the LEDs but given all the other failures I don't hold out much hope.

 

Some LEDs are worse than others and some sockets are worse, where one is in the cabin has a large effect.

 

I've even put some of the old halogen bulbs back and in some locations they cause it too, but only when in series with leds. Utterly confused.

 

Top Cat

[Geo]

Here's an update on things I have tried, all unsuccessful

 

Ensuring aerial ground is properly connected to hull

Removing corrosion from aerial inner conductor joint

Powering radio from independent power supply

Adding ferrite rings to light leads

Moving rear speaker wires away from power wires

Twisting rear speaker leads

 

 

I've just about run out of ideas, the only thing I can think to try is adding 0.1 micro farad capacitors to the LEDs but given all the other failures I don't hold out much hope.

 

Some LEDs are worse than others and some sockets are worse, where one is in the cabin has a large effect.

 

I've even put some of the old halogen bulbs back and in some locations they cause it too, but only when in series with leds. Utterly confused.

 

Top Cat

 

My gut is suggesting that this is very wide band and there are lots of dodgy connections.

 

My next step would be a Signal Analyser to see exactly what your dealing with.

 

ETA do you know any local radio amatuers? If so have a chat with them, they might have an analyser and some of them could well be skilled at the black art.

Edited October 24, 2016 by Geo

[Top cat]

Thanks Geo

W

I think you are right, I'm thinking that there are many causes and one won't stop it till they have all been tracked down. Most of the connections are with spades and the wiring is robust as it was designed for halogens.

The worst one seems to be where I rewired and have a cable going from one side of the boat to another. Thats the one where if imadd a halogen in series with a led it gets worse.

 

Adding capacitors made no difference.

 

I think we will just listen to the radio in the dark

 

Top Cat

Edited October 24, 2016 by Top cat

[WotEver]

Simple thing to try...

 

Do any of the boats around you have a magmount aerial? Could you borrow it as a test?

 

Tony

[Top cat]

Tony

 

Thanks for the suggestion, there's no one near us but I will try and track a mag mount aerial down. All the ones ive seen are for digital radios with a smb connector. I'm starting to suspect the aerial lead because of the way the radio is affected by where one stands. Trouble is its behind the cladding and the radio doesn't have a standard tv style coax aerial connector but what I think is a Jaso. Which is slightly bigger.

 

Top Cat

[WotEver]

TC - many on Ebay if you wanted to take a punt.

http://m.ebay.co.uk/itm/Auto-Car-Radio-Magnetic-Base-Black-FM-AM-Antenna-Aerial-18cm-Long-/191498030992?nav=SEARCH

[Iain_S]

Tony

 

Thanks for the suggestion, there's no one near us but I will try and track a mag mount aerial down. All the ones ive seen are for digital radios with a smb connector. I'm starting to suspect the aerial lead because of the way the radio is affected by where one stands. Trouble is its behind the cladding and the radio doesn't have a standard tv style coax aerial connector but what I think is a Jaso. Which is slightly bigger.

 

Top Cat

 

How is the radio affected? Does the interference get worse and the signal remain about the same, or does the signal disappear?

 

If the former, a braid breaker in the antenna coax might do the trick. This is a fairly standard design. The coils are usually five or six turns of copper wire formed around a 5mm drill, or similar.

 

If the latter, something is seriously up with your antenna!

 

 

Edited to add : Leave out the resistor. Static won't be a problem: galvanic corrosion might be.

Edited October 24, 2016 by Iain_S

[WotEver]

 

How is the radio affected? Does the interference get worse and the signal remain about the same, or does the signal disappear?

 

<snip>

 

If the latter, something is seriously up with your antenna!

 

The latter, I believe.

Here's an even cheaper one: http://www.ebay.co.uk/itm/Car-Accessory-Magnetic-Base-Roof-Radio-FM-AM-Signal-Booster-Antenna-Nice-item/351144796889?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D37123%26meid%3Dc4fcf42dffbf4187a94d1076723f1681%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D191498030992

[Top cat]

Thanks Tony

 

I decided to have a go at the one thing left that hasn't been cleaned, replaced or upgraded , the aerial lead. I finally managed to get an adapter apart and plugged in a new lead going to a spare aerial which I jury rigged to the roof earthed via mole grips on a handle.

Immediately got far better reception which wasnt affected by the lights RESULT !

All I've got to do now is get the new lead down to the radio internally, there is no way the connector is going down the conduit so I'll have to get devoius.

 

The real test will come after dark, it was always worse then fingers crossed.

 

Lesson learned, I had my suspicions about that cable from day one , should have bitten the bullet and changed it.

 

Top Cat

[WotEver]

But... it'll be earthed to the hull again, which is a bad thing. A magmount won't be.

[Top cat]

Good point I'll put a capacitor in the ground wire, one of the ones that didn't do anything on the LEDs.

 

Normally reception get much worse after dark but tonight it all continued to work

 

Top Cat

[Geo]

Good point I'll put a capacitor in the ground wire, one of the ones that didn't do anything on the LEDs.

 

Normally reception get much worse after dark but tonight it all continued to work

 

Top Cat

 

Sounds a good result, good signal level overrides interference.

 

TC go with the gut, amazing how often it is right

[spadefoot]

So it was the aerial after all & not the speaker leads. Well there's a surprise. May I ask what kind of radio it is? Is it a car-dashboard type, that you've had to pull in & out of its aperture every time you've tried to sort the problem?

[Top cat]

Its a car radio (Alpine) but its installed on the front of a cupboard so I have good access to the rear wiring. Actually yes it is the speaker wires picking up interference from the LED lights. Which was being amplified by the radio operating at high sensitivity because of the poor aerial. Sorting the aerial has fixed the problem in this location but I'm sure it will recur if we move to a location with a marginal signal. So I've masked the problem but not got to the root cause, which is noisy LEDs and long wires to the rear speakers.

 

The key learning that might be of use to others is.

 

If your radio reception varies as you move around the boat, check your aerial and its connection. Aerial cables can deteriorate.

 

Top Cat

[spadefoot]

Its a car radio (Alpine) but its installed on the front of a cupboard so I have good access to the rear wiring. Actually yes it is the speaker wires picking up interference from the LED lights. Which was being amplified by the radio operating at high sensitivity because of the poor aerial. Sorting the aerial has fixed the problem in this location but I'm sure it will recur if we move to a location with a marginal signal. So I've masked the problem but not got to the root cause, which is noisy LEDs and long wires to the rear speakers.

 

The key learning that might be of use to others is.

 

If your radio reception varies as you move around the boat, check your aerial and its connection. Aerial cables can deteriorate.

 

Top Cat

Hmmm. Intriguing. So are you saying that the radio picks up signals in its output leads, then somehow feeds them back to the input stage, amplifies them, and then puts that signal back on the output leads?

[Top cat]

Yes I think thats exactly what's happening. I think it's happening all the time but its noticeable when the automatic gain control on the input is turned right up because of a weak signal. If the signal is good there is less amplification . I can just about detect a slight hiss now when I turn on the lights but its really subtle, you have to be looking for it.

I don't think the designer had in mind someone hanging 40' long cables to the rear speakers.

 

Top Cat