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I know you can't even think of hearing it in the Spider but can anyone say what the noise suppression characteristics of the 101 engine are--i.e., were special plug leads or anything else used? My period AM-only Blaupunkt is overwhelmed.

Jeffrey
 

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I've got a slightly more "modern" AM FM Blaupunkt stereo pushbutton style radio in mine. I put a noise reduction electronic component on the power line in,(some radio shack thing) and it helped quite a bit. I still get some noise, even though I have the right type of spark plug & wires. I think now it is actually picking up the interference though the air from the antenna, and not from the 12V system directly.

I bet a more modern electronic CD player type of radio (which does look odd in a 1960 car) would work fine. I had the same problem in 1967 Fiat Spider, but it went away when I put a modern radio in it.
 

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Period correct radio noise.

Once, somewhere here on the BB, I saw a photo and later a discussion of a single capacitor mounted near the regulator on the firewall. As I remember, this was a factory install. I had never seen another like it in 40 + years working on these cars. Any modifications that really would work, would be left to the radio installation crew. On a Ferrari 275 GTB I still own, it came with your same period German radio mounted in a period correct upholstered aluminum unit over the drive shaft hump. Some evil doer carefully stole the unit, leaving the radio, speaker and the rest. This car had 2 brown bakelite suppressors on each coil HT lead. Nothing on the alternator, and carbon core suppressor HT wires to the plugs:rolleyes:. Only time you could hear the radio was if the car was not running:eek:. In restoring this car, all the radio stuff was removed and the car returned to it's as built condition. There is just too much electrical noise generated by an old Ferrari V12. All my home TV's turn into ignition analysis tools when I run it in the garage:p. Also, the same is true for my '65 1600 spider Veloce. It will take a good, knowledgeable radio shop to quiet your vintage radio. I believe that tube type radio's may be more sensitive to this HT noise, but I have no experience in this area. :D Gordon Raymond
 

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Radio Suppressor?

Gordon,
Is that the "can that is mounted near the voltage regulator as in the photos on Pat Garrett's 390392 post?


Terry
 

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That's the one, Terry. Interesting isn't it? I think it was mentioned that there are others out there like that as well. I have never seen one that came that way like Pat's. No reason to believe Alfa did not add one to any car with a factory radio. I wonder if there is a record of how many cars came with a radio installed from Alfa in the Giulia / Giulietta spider cars. Anyone know?
Gordon Raymond
 

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Discussion Starter #6
Capacitors and ground straps

Since my original post I've done more research on the noise suppression problem. Most of the hard work was done by a fellow named Garver, probably an electrical engineer, who probed around his Spider's engine compartment with a field intensity meter, analyzed the results, and reported to the Alfa Owner about them, in 1963. (That was when there were virtually only Giuliettas in the USA and the Owner was much more technically oriented than it is today).

The report indicated that the suppression problem came from the lack of a direct grounding path from the coil to the engine, which caused high-frequency ignition pulses (from low-voltage side of the coil) to be routed through the body, actually producing a high-frequency radio signal to be picked up by the radio. The body of the car was the transmitting antenna for this signal. You can check this out by trying to use a battery-operated portable radio in various locations around the car. The suggested solution was to mount a 1" wide ground strap directly between the case of the coil and a suitable bolt on the engine. The ground strap was suggested in lieu of a wire or cable because these high-frequency currents travel mostly on the surface of conductors (that's called "skin effect," of course).

For my own 2 cents, a hefty capacitor--like the one shown in the previous posts--might suppress the high-frequency components of these currents and work to suppress radio noise, with the result, I assume, depending on where it was placed. The objective would be to suppress the passage of HF through most of the body by shorting it directly to the body at the source. I haven't tried it myself but on the basis of the preceding paragraph it might work if connected from the case of the coil to the body. The connection shown near the voltage regulator would not be as good. Another suggestion would be to place the antenna as far from the coil as possible--on the rear fender, for example.

Given this information I've forsaken the use of a radio in my Alfas for the moment. The AM-only Blaupunkt in my Sprint is hopeless; the AM-FM period radio (not Blaupunkt) in my Spider works sort of on FM and not on AM (with the antenna on the L rear fender). Someday I might try a ground strap on the Sprint.

Previous discussions in Alfa groups indicated that Alfa never supplied radios from the factory; they were always dealer-installed. Of course you'd order it and have it installed before you discovered that it didn't work. . . .

Jeffrey
 

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There is a firm in the UK that provides a modern radio with all the bells and whistles in a period case of you choice. FM, iPod compatible the works and as far as I can see they do not have a reception problem. Any experience of these type of set in our cars?
 

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The capacitor mounted near the voltage regulator was installed on my 1600 Veloce as well. I have seen several cars like this, but not everyone had it. The noise came from the distributor cap as well as the unshielded spark plugs and copper ignition wire. The car was a traveling RFI field. I wound up putting the bakelite carbon suppressors on the end of the plug wires, getting the Champion R (radio suppressor) plugs and putting an inline suppressor to the dist. cap just so I could listen to my cassette player. On my 71 GTV I put the later VW metal suppressor caps on the end of the green wires and that seemed to have resolved most of the problems.
 

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Gentlemen,

While I can't address the details on other cars, perhaps this will be helpful:

I have an August 1965 production Giulia Sprint GT (105.02), still all original, including the dealer-installed Blaunpunkt "Frankfurt" radio.

I had been puzzling over the seemingly non-factory bit of wiring running from my voltage regulator over to the capacitor mounted to the side of the generator, when I looked again at the original installation instructions sheet for the radio. And there it was: the capacitor and the connection to the VR were part of the radio install, as was the second capacitor that's mounted beside the VR.

(The instructions, by the way, are titled "Alfa Romeo 1600 Sprint" and picture a Sprint Coupe. Apparently these instrucitons applied to slightly later cars, too.)

I've attached photos of the capacitors and wiring.

The heavy gauge white wire runs from the generator-mounted capacitor over to the VR and attaches to the VR mounting bracket, in accordance with the Blaupunkt install instructions.

The second capacitor, next to the VR, has a red wire running to 12V at the fuse block and a second red wire that loops around and attaches to one of the VR male blade connectors, as shown in the photos.

I can't comment on the function of these capacitors, or on their effectiveness, but they are part of the original radio installation. (If I can figure out how to reduce the size of my scans of the actual instructions sheets I'll be happy to post them, too...)

Hope this helps.

Chuck

PS Smokie the kitten is really enjoying her first Christmas.... :)
 

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RFI is created when there is an arc of electricity. The generator is one source, the distributor cap is another and the spark plugs a third source. The generator brushes going across the field contacts create sparks, albeit minute. The distributor cap makes lots of sparks from the rotor to the cap, as do the spark plugs.

The plugs can be a easy resolution by buying plugs that are "resistant". In many cases this will resolve some of the issues of getting RFI into the front end of a radio. More stubborn cases are resolved by putting a capacitor inline to the distributor cap high tension lead and/or a rotor with a resistor molded in. There is another solution, and that would be to buy the screw on resistors that are in bakelite with a reddish orange color. These work well and don't detract from the appearance of being nonstock. VW used the metal caps over the entire spark plug to sheild RFI from getting into places not wanted. Alfa used these in the '80s spiders and are relatively easy to get, but only as a whole spark plug harness with caps installed.

A good ground is very essential to the whole system. As evidenced by your white wire going to various grounds.

Check the viability of your capacitors. These are electrolytics (Wikipedia link) and go bad. They are paper and foil with type of grease between the sheets and wound up tightly. After a while the coils short out and the capacitor is worthless. It might appear to be working, but when checked with a ohm meter, it tells another story. Heat is a killer of electrolytics as it speeds up the decay process of the internals.

I am not an expert on RFI, but I have some working knowledge, when I installed my ham radio in my Alfa and went mobile. Hope this helps?
 
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