Thread: Puma RF interference AM radio

Looks like I have found the problem.

For future reference:

SVX comes with iPod interface. In mine the iPod cable had been removed. It is a threaded connector with a good RF opening. Insulated the open metal end and then wrapped the end in Alfoil and taped over. Also Earthed the radio chassis.

One of them fixed the problem.

Cheers

RF

What a crock. RF Noise is back.

Reckon there must be a "loose" somewhere and when I was fiddling behind the radio I did inadvertently fix it, but has come off again.

Will be checking the ABS earths on GB and other earths on firewall.

No one else out there had this problem???

RF

I have a lot of issues with interferrence with 702 in Sydney, to a slightly lesser extent with 576 and in a minor way with the others on the AM band. Its been very frustrating. Thought it was the window aerial (I have a Disco). I mounted an external glass mounted aerial (with amplifier) which has highlighted that there are 3 different issues: the gain from the aerial, the amplification and filtering of the signal, and lastly the effectiveness of the head unit.

The signal strength from the new aerial is better than the OEM window aerial, so I get reception for further distances. I also get much better reception with the new aerial when the radio is on and the ignition off (amplifiers don't work with ignition off). However, I'm getting poorer quality of reception. The OEM amplifier and radio gives better quality sound and less interferrence (but still not good).

The instructions for the new aerial referred to metalised window tint being a reception factor. Does anyone know if all/most window tints are metalised? What effect does the metalised window tint have on the reception?

It has been suggested to me by others on this forum that the quality of the head unit is more important than the aerial for best reception. I'm happy to buy a new one but want to understand/solve the signal reception issue first before spending a lot of money on something that may not give a better result.

My Td5 Defender has very poor radio reception at best and also suffers from interference. This may have something to do with the fly by wire throttle as it is worse during acceleration.

A new head unit is on the cards at some time.

[QUOTE]It has been suggested to me by others on this forum that the quality of the head unit is more important than the aerial for best reception. I'm happy to buy a new one but want to understand/solve the signal reception issue first before spending a lot of money on something that may not give a better result [QUOTE]

IMHO I am pretty surprised that anyone would expect AM reception in Canberra of a Sydney station given the Topography and distance.

I was ICE product manager of Sanyo back in 1979-80 and introduced a new line of products. The common complaint from Australian customers then was that AM performance was poor. Nothing has changed.

The reason is that AM stations are like lice in Japan , North America, and Europe, and unless the selectivity of the radio was very high, listeners would often get crosstalk where adjacent stations on near frequencies would interfere.
So nearly all tuners were and are limited to 20Mv senstivity , so that selectivity issues are reduced, as increasing selectivity is expensive.

This of course is the exact opposite of Australia where we need high sensitivity .
As we are such a small market that nobody would make a special tuner for us. This is even more true now as production has gone to China , and tuners are now ICs which are probably standardised between manufacturers.

The only tuners that I know of that were made more sensitive were the Eurovox units fitted to RRCs and Disco and BMW ( which I selected as OEM ) , and of course Holden OEM that were supplied by Eurovox. AFAIR they were 10Mv senstivity, as any more became very expensive.

So you are really whistling into the wind wanting good AM performance and to get Sydney AM from canmberra during the day IMHO would be pretty unusual..
I live on the Central Coast and have great difficulty as the AM signal is constantly degraded by 240 and high voltage hash, and neon lights etc as the receiver gain is at maximum so it pulls in anything it can get. I have a Mobile 1 FM helical antenna with low loss cabling and no car generated interference to speak of.
The best tuners at present are reputed to be Pioneer Super tuners and JVC, but they are still not much chop.
BTW I can get FM on the coast for sometimes hundreds of kilometers. Pity the programming is such crap.
Regards Philip A

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.

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.

That may be so, but I doubt you will find an aftermarket unit with that performance. Maybe a Japanese manufacturer has specified a good radio seeing OZ is such a big market for Mazda.

I would love to be surprised by someone finding a good AM tuner as I have a Pioneer with Ipod control at the moment and its AM stage seems to have a problem as it has a whistle that starts at say 2000Hz and over maybe a minute rises to 8000or so Hz and sometimes back down.

It is independent of anything in the car or the location and seems to be related to how long it has been on. It only happens when the AM stage is flat out at maximum sensitivity. Based on my experience with testing these things with a Sanyo tech , I am pretty sure it is in the radio itself.

Regards Philip A

Originally Posted by Rick Fischer

AM radio

Also interesting is that when the rear window de-fog is selected the interference drops in volume indicating that somewhere there may be a faulty earth

If you want, read up on tuning stubs and transmission lines for radio frequency,
the adding of more wire reducing interference, can be explained but not easily in a couple of lines of text on this forum.

Adding a radio frequency interference filter to the vehicles wiring could alter a wave form or the leading edge of a pulse into the vehicles computer, so that may lead to problems with the vehicles running.
.