I thought as a quick and easy thing to try would be to make sure all the s/p wires were snapped on tightly. Maybe one had come unclipped and the spark jumping the gap was causing the static. I opened the hood and took a look at the driver's side wires at the spark plug end. Couldn't see them very well, so I went to the driver's side and the air intake was completely blocking the way.Of course, when I pull that off, then the steering wheel drive shaft will be in the way. All this makes me long for the 94 Impala SS V8, the 86 Buick V8, the 69 Chevelle Malibu V8, and my first car---a 1957 Chevy Bel Air V8.

 

Mike, if this is true, then why does disconnecting the external antenna eliminate AM stations as well as FM stations? Without antenna attached, you will get zero reception unless you are sitting right on the transmitter. I say there is no AM antenna at all inside the car radio.

 

AM radio stations in US are on 1400kHz, while in Poland it is 225kHz. That is what makes difference. Sorry, I haven't evaluate the "AM" term close enough. I was pretty sure it means the same as in my country and I ended down the rabbit hole.

 

I understand Mike, AM band in USA is medium wave about 530 kHz up to around 1700 kHz. 225 kHz would be longwave.

 

Update from the OP. I was having this static noise only on AM. My favorite AM station is a news/talk station at 560 AM. The problem has now gotten worse on AM and has traveled to the FM stations. I have got to get serious about this problem. I have planned to get the AC Delco parts for a tune up: Distributor rotor , cap and spark plug wires. Any other critical ignition parts that I should get that relate to the potential static situation ? Thanks,

 

Years ago back before FM was heard of and all there was was AM with non restive spark plugs or solid/wire core plug wires you would get the whine on AM stations. { Yes I'm that old }
A weak plug or restive wire breaking down, and as stated above a alternator with a weak diode will give the same affect.
I don't know if they are still available but there was a coil like unit that went over the antenna wire that canceled the affect. Some external antennas themselves have the coil built on them

 

Radio noise can be from:

Antenna/ground
Alternator or its ground
Battery/chassis/block ground
Radio ground
Ignition components or their grounds

If you are going to replace the ignition components, as a minimum make sure that the spark plugs are the resistor type. There are also shielded spark plug wires.

George

 

I do have the VSS get into the FM radio - mind you I said FM when I drive into the garage with the radio on and the station is lost (weak signal)
Took me a while to figure the source but it's definitively the VSS.

But then my radio is a replacement wired into the factory wiring.
As I get no signal from the VSS as soon as the radio-stations signal is strong enough I don't care.

Have to try to see if I get the same signal on AM. (As per what I know of radio signals it could be even more pronounced)

 

Odat in Wyoming---I do remember the Resister type spark plugs.

 

Original Poster updated this thread:
To resolve the radio static, I thought I would try a few things that are due , actually overdue, to see if they would eliminate this static. I wanted to do it in stages so I would know what the specific problem was when it was eliminated. My first project was to replace the distributor cap and rotor with all AC Delco parts. I just did that--thanks YouTube !--and it worked. No more static on my favorite AM station 560 on the am dial. I tried other , more distant am stations, and no more static. There was significant wear on the tip of the rotor contact. The 6 contacts in the cap were showing white corrosion. Both needed changing badly.
BTW one Youtuber recommends using Accel parts because they have brass contacts in the dist. cap.