Any AM gurus?

[velozp]

Hi My factory AM 8 track has issues. The 8 track player works fine but all of a sudden no am. Any old guys out their ? I also think I can get an FM converter that will probably surfice. The dial works fine , goes to all of the stations, just cant get any reception. I have a wire plugged into the antenea which should at least get some signal. Any thoughts?

 

[mmissile]

AM antennae is imperative to be in good working order.

 

[khryslerkid]

Try to use a regular antenna. I don't think just a piece of wire will work as good. AM waves are pretty weak and not too many stations useing them as much.
AM waves travel horizontal. FM waves travel vertical. FM converters work pretty good too.

 

[Darthomas]

Electronic and Radio Engineer at your service.
First, even if there is no antenna, by keeping your ear very close to the speaker, you should be able to hear a small thud when turning on the radio.
This would prove that the audio amp is alive. The next likely fault is the switch that selects between the tape head or the tuner when the tape is inserted or removed. It may simply not be making good contact. Works a tape cart in and out firmly several times and see if the tuner signal comes back.
I just put an FM converter in my 2013 Dodge 2 days ago.
So now I can Bluetooth audio from the phone to an FM frequency and listen on the FM, it gets converted to AM, and I can choose to hear the music on AM, which I prefer. Instead of tuning the converter to exactly 1710 AM, I tune it to 1705 khz. That way the treble in the music sounds as crisp as it does on FM but the music has much more "body".
I can also then pick between listening on 1700 or 1710.

Give it a try and let me know.
The radio is probably OK.

 

[oldbee]

There is also a "tuning" screw usually close to station knob that needs to be set right. Believe it matches radio to antenna impedance.

 

[velozp]

Ok guys as usual this site always helps. I will use a real antena and see. And I will try to inserting a tape several times. I just love that ol school equipment. At cruise notes, thats the 1st thing people ask, does the 8 track work? Luckily I found some 8 tracks at a flea market with the carrying case. What nostalgia gotta love it.

 

[Darthomas]

There is also a "tuning" screw usually close to station knob that needs to be set right. Believe it matches radio to antenna impedance.

Correct. That is a trimmer capacitor, which allows the "electrically way-too-short" whip antenna to be actually tuned to reasonance. It also permits perfect peak sensitivity with different vehicles and antennas. You set the tuner to a weak station above 1400 and adjust for loudest response.

 

[Darthomas]

Any news?

 

[Nacho-RT74]

Long time ago I got one Multiplexer Am/Fm radio but didn't work at all, then got another one that worked nicelly but after a week suddenly the Am stop to work.

Take it to a shop to fix it and turned out the AM internal antenna I think it was ( a long magnet with a coil around ) got the coil sulfated and broken. The firts radio was a nice donor for the working one, and voilá! Am fixed

 

[Nacho-RT74]

at the same time power transistors were changed too for a more powerfull ones and got more juice from it

 

[velozp]

I will work on it this weekend. Anyway some trivia. The factory am 8 track radio I got at a swap meet came with a factory fader and a splitter box. Right now I have 1 center speaker and 2 rear speakers hooked up. It works ok but not alot of power from the back speakers when i fade it just to the rear. I think my aftermarket speakers are too big in ohms. Also what does this factory splitter box actually do? I have heard its called audiophonic?

Thanks Happy new year and be safe!!!

 

[bigmanjbmopar]

Great thread, one question I have is I noticed on my 69 am thumbwheel that it wouldn't even power on unless an antenna was plugged in? I traced it out and sure enough the power feed series's in with the antenna, thought this was strange?

 

[oldbee]

Bigman it sounds like yours is getting it's ground thru the antenna, not good.

 

[bigmanjbmopar]

Maybe? Havent used in a long time that test was on a bench too