In the past week, I've managed to fit a Bendix-branded AM-FM radio to my MG. This is an early 70s radio that's branded "British Leyland" and is the sort that would have been fitted to the car when new(none shipped with a radio, but this is one of the sort a dealer would have installed).
My "original" antenna(again, really dealer fitted) on the front passenger wing had its wire chopped off, so I swung by Autozone and picked up a 31" telescopic whip antenna and mounted it to the original mounting. As I understand it, 31" is a good compromise length for most of the FM band. I hooked all of this up, and it works perfectly. I can get all the local FM stations and plenty of more distant ones. In the evening, I can reliably pick up 840AM and 650AM, two clear channel stations of interest to me. The former is a ~200 mile line of sight, and the second probably more like 250 miles.
That's all good and well, but that's in the garage without the engine running. It all goes to heck when I start the engine. With the engine running, at best I can pick up strong local stations through a lot of static and never really very clear.
I know that, first of all, the ignition can wreak havoc on the radio reception. My antenna is a few inches above the ignition coil, and not too far from the distributor. I don't have resistor plugs fitted(I used the now-discontinued NGK BP6ES, which I fortunately have a good stock of) but do have NGK carbon core wires which are supposed to be suppressed. The rule of thumb I've always heard is that either resistor plugs or resistor wires are fine, but that using both can affect ignition energy too much. I can fit NGK BPR6-ES plugs if needed, but I'd prefer to not.
The radio did come to me with a big inductor looking thing that was tied into the radio +12V at one end with a big spade lug at the other end that was under the grounding post on rear of the radio. I didn't wire this in(although it's still there) as the hot side insulation is dry-rotted and flaking. I'm wondering if this is the issue, and if so if replacements or a modern equivalent are available(I didn't see an obvious way to just replace the wire).
Otherwise, I'm GUESSING maybe the issue is in something "dirty" in the car power supply. It's on what should be a "clean" circuit that has the headlights and brake lights. The alternator is new(~18 months old) and hasn't given me any reason to think the rectifier is bad.
Is there anything else I should be checking, or if not I'm wondering if there is a filter I should be using somewhere on this to "clean up" the power supply. Can anyone offer any advice?
My "original" antenna(again, really dealer fitted) on the front passenger wing had its wire chopped off, so I swung by Autozone and picked up a 31" telescopic whip antenna and mounted it to the original mounting. As I understand it, 31" is a good compromise length for most of the FM band. I hooked all of this up, and it works perfectly. I can get all the local FM stations and plenty of more distant ones. In the evening, I can reliably pick up 840AM and 650AM, two clear channel stations of interest to me. The former is a ~200 mile line of sight, and the second probably more like 250 miles.
That's all good and well, but that's in the garage without the engine running. It all goes to heck when I start the engine. With the engine running, at best I can pick up strong local stations through a lot of static and never really very clear.
I know that, first of all, the ignition can wreak havoc on the radio reception. My antenna is a few inches above the ignition coil, and not too far from the distributor. I don't have resistor plugs fitted(I used the now-discontinued NGK BP6ES, which I fortunately have a good stock of) but do have NGK carbon core wires which are supposed to be suppressed. The rule of thumb I've always heard is that either resistor plugs or resistor wires are fine, but that using both can affect ignition energy too much. I can fit NGK BPR6-ES plugs if needed, but I'd prefer to not.
The radio did come to me with a big inductor looking thing that was tied into the radio +12V at one end with a big spade lug at the other end that was under the grounding post on rear of the radio. I didn't wire this in(although it's still there) as the hot side insulation is dry-rotted and flaking. I'm wondering if this is the issue, and if so if replacements or a modern equivalent are available(I didn't see an obvious way to just replace the wire).
Otherwise, I'm GUESSING maybe the issue is in something "dirty" in the car power supply. It's on what should be a "clean" circuit that has the headlights and brake lights. The alternator is new(~18 months old) and hasn't given me any reason to think the rectifier is bad.
Is there anything else I should be checking, or if not I'm wondering if there is a filter I should be using somewhere on this to "clean up" the power supply. Can anyone offer any advice?