radio reception

[adm22]

Is there something one needs to do to get decent AM radio erecption in these cars? I no longer have the factory antenna on my car and the AM-FM radio that until recently was in the car- had almost non extant AM reception and FMreception that was not as good as I thought it should be.

Over the weekend replaced it with an AM FM 8 track that I had taken to a refurbishing shop they replaced a bunch of capacitrs and the belts and such for the 8 track as well as the lights inside. They showed me it worked before I left the shop with it and tit was getting good AM reception on a weak station with only a small piece of wire stuck in the antenna port. When I get it in the car the 8 track works- now I cant find my tapes FM works great much better than the old one and the really strong AM stations almost come in. Not yet tried driving with it but fear that a whine may appear when the engine is on as that happened before.

Any one else encounter this in the past?

 

[Don C]

What are you using for an antenna?

 

[adm22]

A factory style replacement antenna mounted to the fender.

 

[Don C]

Make sure that the center wire isn't shorted out and isn't broken. The outside (shield) needs to be grounded. There should be an antenna trimmer on the radio near where the antenna lead plugs in to the radio. Adjust it for best reception.

 

[72HCODE]

for am/fm cars if you have the oem points voltage regulator then you needed a radio condensor installed in the engine bay wire harness. there is a plug next to the voltage regulator off the harness with a bullet connector, that plugged into the radio condensor which was then mounted to the chassis for ground. it helped reduce radio interference noise.

here is where things get fun if you have a factory radio:

the 71-72 radio used a longer Whip antenna that you could retract. the 73 used a fixed height shorter antenna.

what i found: i had some aftermarket antenna and a sears radio originally . I repaired the original harness and got a 72 radio and bought a 73 antenna and had bad reception. later i bought a 71-72 reproduction antenna to be more correct for my car and my radio reception improved a lot.

now there are modern antennas that can increase reception. now on older radios there was a tuning sweet spot for antenna length and with my retractable antenna i can actually adjust reception on a weak channel by changing the antenna height. food for thought.

here things get more fun:

do you have after market: coil, ignition wires, spark plugs?

these SERIOUSLY mess with radio reception.

spiral core wires or wires that claim they are shielded are utter B.S. take them off and install a set of OEM carbon filament core wires and watch your radio reception improve big time, super high voltage coils cause a feedback in the electrical system of the car (you hear a buzzing) and some spark plug designs cause a resonance in the electrical system, you hear a ticking through the radio for each time a plug fires.

Routing of ignition wires can also make a difference spacing them out with holders and keeping them away from other wires and preventing a cross fire on Wires 5, 6 just by moving 5 and 6 away from each other.

old radios also have issues with the capacitors. even if you have replaced them with new ones most old radios still need to warm up a little to work right. sometimes it can take 10-15 minutes if a car has sat a long time to get the radio working 100%.

on my car my Volume is very low and i have interference when i start the car after 10 minutes my volume suddenly comes up and the background noise drops off.

 

[jeff8877]

72hcode...I love your responses as I learn something every time. Thanks for your time, knowledge and effort.

Jeff