1969 Delco Car Radio Saga

g a 1969 GM pick-up truck, and brought me the vintage radio from it to see if I could do anything with it. He had *NO* interest in converting to FM, m uch less stereo, all he wanted was to get the AM back.

very day since 1969, fully encrusted with filth, grease, what looked like m elted sugar, plastic and more. To the point where the tuning knob was locke d, as were the preset buttons. This is a solid-state radio, not tube, of co urse.

ing the top and knobs, I put it on the top shelf of the dishwasher (Bosch) and ran it through a full scrub cycle (alone), then dried it in the oven fo r 2 hours at 175F. It came out sparkling clean, and with (thankfully) the b ack-painted numbers on the dial intact.

lements. They get too hot in some cases.

resistance, two of the internal sections were shorted such that capacitanc e was high, but they were, effectively, the same cap. I replaced the entire ty with new caps rated slightly higher in capacitance, twice the voltage.

uorescent shop light.

of electronics I have put through the dishwasher. Two Zenith TransOceanics , one Dynaco FM5 tuner, one Dynaco PAT4 pre-amp and one other US tuner. Hav en't lost a patient yet.

And here I thought that dishwashers were made for steaming fish..

Did you use standard dishwasher detergent or something else?

Was SWMBO around at the time?

Not so much on a Bosch. There is no exposed heating element, so the water n ever gets to more than 180F, and then only during the actual washing cycle. The drying cycle uses residual heat and fan-forced air. So, the water is h eated directly, not the entire inside of the dishwasher, and there is nothi ng other than the fan blowing during the drying cycle.

Standard high-phosphorus/bleach detergent, yes. We are on a municipal sewer system, so I do not worry about phosphorus discharge. Normally (and this is normal?) I use no detergent at all. But this unit was beyond merely filt hy - the heat-sink fins were indistinguishable, that bad.

My wife is not at all squeamish about this sort of thing, I have cleaned/re stored stuff for her that she thought was entirely unsalvageable. The dishw asher has a stainless steel inside, the oven is actually self-cleaning, and there were no untoward smells. She sees it as another demonstration that I am 'handy' to have around.

Peter Wieck Melrose Park, PA

Boiling point is 220F.

Nice story :)

Sorry, that was a typo. At least know I was *thinking* 212... as the engineer arrived to certify our new footings..

Apparently you can cook fish fingers in the toaster.

What's that in Centigrade - apparently germanium transistors brew up somewhere around water boiling point.

Where do you live, the bottom of a lake? 212F at 1 bar!

Cheers

Phil Hobbs

Peter Wieck Melrose Park, PA

g a 1969 GM pick-up truck, and brought me the vintage radio from it to see if I could do anything with it. He had *NO* interest in converting to FM, m uch less stereo, all he wanted was to get the AM back.

very day since 1969, fully encrusted with filth, grease, what looked like m elted sugar, plastic and more. To the point where the tuning knob was locke d, as were the preset buttons. This is a solid-state radio, not tube, of co urse.

ing the top and knobs, I put it on the top shelf of the dishwasher (Bosch) and ran it through a full scrub cycle (alone), then dried it in the oven fo r 2 hours at 175F. It came out sparkling clean, and with (thankfully) the b ack-painted numbers on the dial intact.

lements. They get too hot in some cases.

resistance, two of the internal sections were shorted such that capacitanc e was high, but they were, effectively, the same cap. I replaced the entire ty with new caps rated slightly higher in capacitance, twice the voltage.

uorescent shop light.

of electronics I have put through the dishwasher. Two Zenith TransOceanics , one Dynaco FM5 tuner, one Dynaco PAT4 pre-amp and one other US tuner. Hav en't lost a patient yet.

Fish fingers must be very small. Do you eat them by the gross or the ounce? Lenny

Had some boards at work with 'lytic caps leaking acid. SWMBO said no way br inging them home. Company bought a dishwasher explicitly for electronics cl eaning and it works very well. I use a small amount of detergent, no active drying in the dishwasher but we also have a commercial food dehydrator for 'baking' tapes. 17 hours at 125F makes the boards look and work like new a gain.

Boards have had water soluble flux since they banned the solvents to protect the ozone layer.

AFAIK: all PCBs are cleaned in water nowadays.

g a 1969 GM pick-up truck, and brought me the vintage radio from it to see if I could do anything with it. He had *NO* interest in converting to FM, m uch less stereo, all he wanted was to get the AM back.

very day since 1969, fully encrusted with filth, grease, what looked like m elted sugar, plastic and more. To the point where the tuning knob was locke d, as were the preset buttons. This is a solid-state radio, not tube, of co urse.

ing the top and knobs, I put it on the top shelf of the dishwasher (Bosch) and ran it through a full scrub cycle (alone), then dried it in the oven fo r 2 hours at 175F. It came out sparkling clean, and with (thankfully) the b ack-painted numbers on the dial intact.

lements. They get too hot in some cases.

resistance, two of the internal sections were shorted such that capacitanc e was high, but they were, effectively, the same cap. I replaced the entire ty with new caps rated slightly higher in capacitance, twice the voltage.

uorescent shop light.

of electronics I have put through the dishwasher. Two Zenith TransOceanics , one Dynaco FM5 tuner, one Dynaco PAT4 pre-amp and one other US tuner. Hav en't lost a patient yet.

I have alot of music on reel to reel. some of the oxide comes off of some o f these. I know that their days are numbered. Can I save them? thanks Lenny

What' the deal on baking tapess

Reminds me of the "best butter" used by the March Hare in his watch, as told by Lewis Carroll!

Mike.

We used a citrus based solvent in an industrial circuit board washer at the Microdyne plant in Ocala, Florida. I don't remember the brand, but it was a modified restaurant type dishwasher that sat on top of a stainless steel tank that held the solvent. The modifications were that tank, and an additional pump to circulate the solvent between the rinse stages. That cut the cleaning costs, and also trapped any parts that came off of new boards due to problems in the reflow oven. It had over a dozen solid state relays added, for the modified wash cycle.

Most of those early Delco solid state radios were a breeze to fix. Most spent less than 10 minutes on the bench, since the biggest failures in the '70s & '80s were open RF/IF transistors, or a shorted output transistor. They failed so often that the radio bench had its own inventory of parts right above the test equipment. It often took longer to do the paperwork than the actual repairs. :)

A curved hemostat, and clipping the leads to different lengths let you replace the RF transistors without removing the circuit board from the tuner. That trick alone, cut about 15 minutes from each repair. The first shop would remove the board, and quite often they would break the tabs off the coils and then they would wait for a new tuner to be ordered.

That depends on the backing used. Acetate requires a different method than mylar.

Not nice to hijack a thread.

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