radio suppressors

[tj1852]

I'm getting lots of ignition noise through the Delco AM radio in my '62 hawk. I managed to get my hands on three nos suppressors for the coil, generator, and voltage regulator. I can't find any reference to them in the shop manual--anyone know where they go?

Many thanks,
Tim

[starlightchamp]

Not sure where they all go, but my experience is they don't help much anyway. Number one culprits are the
ignition spark plug leads and plugs. The leads should be of resistor wire and the plugs resistor type.
Unplug your antenna from the radio and notice if the static is greatly reduced. I f so, noise is radiating
into the antenna from the leads. Sometimes wrapping aluminum foil around the antenna lead will form a Faraday shield
to reduce the pick up. Be sure the antenna base is well grounded to the body.
I f noise still there with antenna off, check that you have s good ground on the radio chassis
and the point/coil capacitors are not open or shorted. Does the radio have a mechanical vibrator?
Lot's of noise from these until a strong signal captures the IF. Fix here is to install a solid state vibrator.
The coil suppressor would go in the primary coil lead in series.
Is this a new radio install ?

...Dick Curtis
Starlightchamp

[tj1852]

Hi, thanks for your quick reply,

The radio is original to the car--it may well need a solid state vibrator, as you mentioned. I installed a new trunk mount antenna when I restored the car a few years ago. I'll start by installing resistor wires and plugs and making sure the radio and antenna have good grounds, and go from there.

Sure would be nice to have it working better for this trip to AZ.

Thanks for your help,
Tim

[Bud]

The 62 Hawk radio doesn't use a vibrator. It is solid state if it's a pushbutton and a hybrid with tubes and transistors if it's a manual tuning model. Be sure that the antenna is grounded to the trunk lid and the lid is grounded to the body. The NOS noise suppressors are probably no good electrically as the insulation inside breaks down over time. NAPA has new ones, if I remember correctly, the part number is RC1. They are installed on the + side of the ignition coil, the armature lead on the generator and the battery terminal on the voltage regulator. Be sure that the engine is grounded to the frame and firewall as a dirty or missing ground wire will cause noise problems in your radio. Bud

[StudeRich]

And the survey says:... the number TWO reason for static, is the Oil Gauge copper line (dash to engine), it is supposed to be grounded with a braided ground strap clamped to it, at a break in the rubber covering in the middle of the firewall.

These were often ignored by sloppy Dealer Service Depts. when installing the AC Radio Install Kits.

[Bud]

StudeRich is correct, I forgot about the ground strap to the oil pressure gauge line going through the fire wall. My 62 Hawk has the ground strap installed on the oil line and all of the Hawks that I' ve serviced over the years have had that strap installed and didn't have noise problems. Bud

[tj1852]

Thanks for all your help guys. I do have the braided oil pressure line strap, so I'm covered there. As soon as I get a chance, I'm going to order some new resistor wires and pick up some new resistor type spark plugs. I may as well install the suppressors I've got, and I'll ground the antenna and the trunk lid, as well as the radio itself.

As I was driving today, I noticed that when I drive close to overhead wires, I loose reception all together, so there may be something wrong with the radio itself.

The manual tune radio in my '64 Commander seems to get a lot better reception and have a lot better sound, so I know that I can do better.

Again, thanks

Tim

[PlainBrownR2]

As I was driving today, I noticed that when I drive close to overhead wires, I loose reception all together, so there may be something wrong with the radio itself.

For the AM bands this a pretty common situation when driving under overhead or high tension wires. When we listen to AM even in the Crown Victoria, which is a modern vehicle too, the signal will drop out when we pass under wires. The electromagnetic field generated by the overhead wires envelopes the passing car and can drown or interfere with receiving stations.

[gordr]

IMHO, the best deal for ignition noise is to use what is called "magnetic suppression wire" for the spark plug cables. They consist of a fine continuous metal wire wound around a magnetic rubber core, and they function like a radio-frequency choke, blocking RF radiation from the spark, but allowing the "DC" spark current to pass unimpeded. In my experience, they clean up ignition noise better than resistor wire.

Take note that, if the radio is not getting a strong signal from the antenna lead, the AGC circuit will make the RF and IF amplifiers run at full gain, and it will pick up plenty of electrical noise from the engine, even if it is properly suppressed.

If the radio fades out passing under power lines, etc., it's getting a very weak signal indeed. Try adjusting the antenna trimmer screw, while tuned in to a weak station above 1500 kc. One some radios, the trimmer screw is hidden behind the tuning knob escutcheon, and on others it's on the back or side of the radio, near the antenna socket, often in a recess.

Particularly on a Hawk with its rear-mounted antenna, but often on other models, too, the antenna lead-in can fill up with rain water seepage, and corrode through the center conductor, which is very fine wire. Or it can cause leakage resistance between the center conductor and ground, which saps your signal, too. Get a good multimeter, and measure the resistance between the antenna mast and the center pin on the radio-end plug of the cable. It should be close to zero ohms, but a value in the single digits is OK. If you are seeing hundreds of ohms or more, or at worst, infinity, the cable is compromised and should be replaced. Next, set the multimeter on its highest ohms scale and measure from the antenna mast to ground, and from the center pin of the plug to ground. You should see infinity (a digital multimeter may keep dithering, trying to get a reading). If you see anything less than, say, 0.5 Megohm, replace the cable.

[Welcome]

>>>The NOS noise suppressors are probably no good electrically as the insulation inside breaks down over time.<<<Bud

Bud, I came into a bunch of NOS Studebaker Noise Suppresser Kits a while back and have two questions for you or anyone else:

Q #1: Is there a sure/quick/easy way to check the suppressors to see if they are still good?

Q #2: Where exactly are the Hood ground strap attaching points?

TIA

[Bud]

The radio noise suppressors for the generator, regulator and coil are .5 uf paper and foil capacitors and can be tested with a radio capacitor tester. Someone that services older electronics equipment would probably have one on their bench. Over the years, the paper insulation in the caps breaks down and then causes an internal electrical leak. Installing a NOS cap probably won't hurt anything, but they won't do anything either. I do a bunch of old radio repair work and I have a good high voltage cap tester on my bench, that's how I know about the problems with the old caps. Welcome, I would be happy to test your supressor caps for the cost of shipping, but my recommendation is to use fresh stock caps. I put braided straps between one of the mounting bolts on the trunk hinges and drilled a small hole in one of the hood hinge brackets and a screw in the firewall. I did that years back when I had a CB radio in the car and had noise in that. Bud