Thread: Puma RF interference AM radio

Originally Posted by Rick Fischer

.... Improved the long range signal strength hugely by plumbing in a 0.8m gutter grip 27MHz CB antenna to the rear window car plug so I could use external in trips and window round home. ...

Thanks for your reply. Not sure I understood half of it.

Are you saying you connected an external aerial wire to the OEM window aerial connector? How did you do connect to the connector?

Originally Posted by numpty

I can receive Brisbane 612 (ABC) all the way to Warwick (around 180k's) in my Mazda 323, but in the Defender it drops out around Qld raceway.

Mazda's old Panasonics are excellent radios. My MX5 radio can pull 666 all the way to the top of the Clyde, or out to near Wagga. Pity is, these days AM had become "Passe", and the head units are optimised for FM Never mind that for Australia, AM MW and SW are the only ones that can do the distance.

Was advised by a radio supplier for truckies, that bang for any buck Pioneer DEH2050 MP/G and DEH59501B are the best after market AM fringe radios around. Both use the same tuning circuit.

I've used them both, the 5950 was in the D2, and West of the Divide, way out in the Centre, and across the top provided excellent AM reception out hundreds of km, as good as the Panasonic in my MX. The 2050 is in the E30.

If I can't get the SVX Clarion to fly properly then the 5950 will be going in, and it's able to drive the SVX's bells and whistles.


I'm getting back to my interference problem tomorrow when I have to have the centre dash out for something else.

Originally Posted by Mundy

Thanks for your reply. Not sure I understood half of it.

Are you saying you connected an external aerial wire to the OEM window aerial connector? How did you do connect to the connector?

Ahhh! I have a lathe, and I turned up a small button adaptor to fit the aerial spring clip Then soldered it all into a co-ax.

RF

Further along with the SVX. Includes a YYYYYYYAAAAAAAAGGGGGGG! moment.

Found that there is an powered aerial signal amplifier. Removed it and increased signal strength, and reduced RF interference, so looks like it is cactus. Used car warranty.

However, did a night drive with the the HDIs lit, that's all of them except the parkers and indicators; YAAAAhhhh/gggg moment. The HDI Ballasts murdered anything other than the local AM stations. Took advice and connected the spotties direct to battery, nearly fixed! Low and High beam to go. Looks like I'll need to further earth and then faraday cage the Ballasts.

Why listen to 702 Sydney in Canberra. It tests the reception and the amount of RF noise. Additionally one can pick up 702 over lots of NSW if you have a "quiet" enough receiver.

Cheers

RF

Well, finally got back to the radio; AM that is.

Replaced the OEM antenna with 900mm Axis unit using RG62 93 Ohm coax, with the antenna coax wired to earth instead of depending on the antenna base. Engine noise all but gone on 702 Sydney in Canberra (is there in the atmospherics). All now dunky dory

If anyone wants improved AM reception, first step is get rid of RG58 or similar 75 Ohm coax and use RG62 93 Ohm. The 75 Ohm impedance is optimised for FM.

Cheers

RF

I too finally have my AM reception much improved. They tell me they ended up putting another earth to/from the radio chassis as well as making sure the old signal amplifier (in the rear RHS?) did not still have power. Not 100%, but a significant improvement and I think a wee bit beter than OEM. Bradtot - your radio awaits!

Brings back memories... Last time I had vehicle-caused RF interference was in my first jalopy, an XR Falcon Wagon. In fairness, I was running wire IGN leads, homebuilt CDI .... and 27 meg AM/SSB CB.
Who remembers salvaged co-ax braid and tin cans over dizzy's and coils ?

In the mean time I've had Aussie, Jap & German cars, all with 'real' antennas. All performed perfectly with good open road reception.

Now my Classic Vogue SE has given it back to me - with interest. Hash from the HVAC motor, very faint IGN noise, trafficator THUMPS and very average range... - Its either low signal/hi-noise or motorboating front end, depending on 'Local/DX' switch.

So much for the 'state of the art', top-specc'd radio and window antenna + RF amp.

Check all the earths on everything, and the radio itself, Modern radios depend too much on the aerial and power earth. The Case earth is neglected. Then solder a proper earth cable to the antenna earth and take it to a good body or engine earth; dont depend on the aerial nut and washers.

Cheers

RF