MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Radia Suppression

First, let me say that I know absolutely nothing about suppressing radio interference.

My FM/AM radio worked fine with my previous distributor, fitted with graphite plug leads and a suppressor attached to my alternator.

I have now reverted to my original MGA distributor, fitted with electronic ignition, wire leads, suppressed plugged caps, but still with the suppressor on the alternator.

FM still works fine but I now have a lot of noise on my AM frequencies (use it a lot in UK for live sports commentary etc - Radio 5 live).

Anything I can do?

Steve
Steve Gyles

Steve, change to the graphite leads, it should cure the noise on the AM band.
Bill Young

Bill

I have not yet found silicon graphite leads of 7mm diameter. All my local suppliers have are 8mm leads and these are too large to push into the distributor cap holes.

Also, my leads are held in place by pointed grub screws in the terminal posts inside the distributor. Is it ok to screw these into the silicone graphite cores?

Steve
Steve Gyles

You can try adding a line noise suppression filter to the radio as well. This is an LC circuit with a leg to ground for clipping and earthing high frequency noise. They don't work all the time, but are inexpensive enough to try. They can be had at any auto parts store, or through catalogs online.

Very important to ensure that your existing grounds are good, as well. The radio case ground should be connected to clean metal on the firewall. It may be that in doing your work, you lifted or left an existing ground off somewhere, which is now causing the noise -- so go back and check your wiring.

AJ Mail

Another thing you can try is to fit a grounding strap onto the bonnett (hood, in the US -- the big metal thing that covers the engine bay), as it can act as a reflector.
AJ Mail

Steve

What's a radia? You mean Rodia, that noisy thing in the dash. I think a later cap will fit, Lucas DDB106? I'll check the number for you. You can then fit push in suppressed leads. Have you got a suppressor on the coil? Is the aerial earthed against the body OK? Aerials differ in quality as well, an in line choke (suppressor ) may help. If all else fails, switch it off and enjoy the exhaust note!

Radioless

Terry
Terry Drinkwater

Terry

My Radia was designed and built by Mr Qwerty in the early 20th century! Having just reached the grand old age of 60 I am afraid he occasionally gets the better of me!

Aldon supplied me with a new distributor cap when they rebuilt my unit. I assumed it was an item to original specifications, but may be not...

I would certainly be greatful of details of a replacement unit that takes modern leads.

Steve
Steve Gyles

Sorry for the absence. I ran into the 7mm versus 8mm problem years ago when using a Vertex magneto. I took a razor knife and trimmed down the insulation just enough to get the lead in the cap. The screw should work ok in the graphite lead.
Bill Young

No, no, Terry - a Rodia is that thing where cowboys ride bucking horses, and bulls, and whatnot. I think he means ray-dideo <grin>.

Anyway, Steve, sorry to have a little sport at your expense - I suffer from "fat finger syndrome" myself.

I don't know about the UK version, or even if there IS a seperate UK version, but the Haynes manual has an excellent section on radio noise suppression, and the general fitting of radios and tape players. Look in the chapter on electrics, just before the wiring diagrams (or look in the index, but what's the fun in THAT?).

Best wishes - - Alec

Alec Darnall

Steve

Distributor cap parts no Lucas DDB106 or Moss GDC103, try silicon suppressed leads as fitted to MGB's, available from Moss. Have thought of a gas raydeo? ( can't seem to get the spelling write ) a carbide one would be OK.


Terry
Terry Drinkwater

Terry

Many thanks. Does the original MGA distributor cap have push in leads or the grub screw type connectors as fitted in mine?

I really must get my radia upgraded. It is coal-fired, smoke-driven and causes bit of a phug in the cockpit - some of the smoke is also beginning to escape from the wires. Alternatively I may be able to get a smoke recharging kit on Ebay.

Steve
Steve Gyles

Terry

Just phoned my supplier. He confirms your GDC103 cap for the modern silicon graphite leads. Apparently it is the original Mini cap.

Steve
Steve Gyles

New cap purchased and fitted with silicon graphite leads. Timing light back working fine with new leads - 32 degrees at 4000RPM, vacuum disconnected, with no jittering of timing mark (earlier thread). 'Radia' successfully supressed with no escaping smoke. Car running great. Successful day and it's hot and sunny on Costa del Fylde.

Steve
Steve Gyles

This thread was discussed between 05/10/2006 and 14/10/2006

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.