Early 1970's Radar Range

Here's a photo of what the screws look like:

It's not a "tri-wing". The center part is raised. It seems like the tool would need to be a hollow piece (like a socket) with 3 notches on the sides to grab on to the screws. That's what I need. Bryan

I would suggest using an old socket or small pipe and grind away part to form three post that fit the head of the screw.

Yeah, those are a pain. What I did was to take one screw I had like that and hammer a piece of pipe over it to form the inside of the pipe to the three notches. But if you don't have another similar screw, I wouldn't recommend doing this on the microwvae though as the vibration of hammering will not be good for it!

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On Fri, 09 Feb 2007 14:49:39 -0800, Totalrod2 Has Frothed:

If the head is big enough take a punch and tap the screw in a counterclockwise direction on one of the three slots just enough to loosen it up then grab it with a pair of needle point pliers.

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794

I looked at my collection of security bits - don't have that one. I'd take a piece of 1/4" rod and saw and grind it to fit. You could also cut the tip off a dollar store screwdriver and do the same.

I managed to get those out once using small pliers. As soon as you loosen them, they should come out easily. Andy Cuffe

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e=Yes

a dremel with grinding disc will put a slot in the heads. But the early 70s nukes are so lacking in safety features I'd replace it.

NT

Will the central pin shear off with a pin punch and hammer, or a ball-mill , like those annoying IBM computer monitor central pip screw heads ? Then lefthand drill and LH drill bit, then easyout if the drill itself does not shift them, if fabricating a tri-wing screw-driver variant fails.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

What safety features? As far as I know, they had all the same interlocks as modern ovens. Microwaves have not changed much in the last 30 years other than cost reductions. Those old Amana microwaves are classic, built like tanks and last forever. Wish I had one myself.

Ever checked one for leakage? ISTR they claimed to cook a chicken in 15 minutes or less. Not while I'm in the same room!

Amana wasn't the only manufacturer to build its microwaves solidly and to last. I have a Sharp Carousel digital microwave I bought new seven years ago. Still works very well in daily use, although I think the door switches are either very dirty or starting to go bad--the oven will sometimes shut off before the end of a timed cycle. Opening and closing the door several times gets it going again.

BTW, I had relatives (now deceased) who owned a digital version of the Amana Radarange (they must have bought it in the mid-1970s). I don't think they had even one repair done on it in the 20-some years they had it.

Microwaves have changed in the last thirty years, but the changes have been minor, mostly to the control circuitry (most micros these days have at least one microprocessor which runs the whole thing). The old Amana Radaranges didn't have the instant-action keys most of today's digital micros sport (my Sharp has nine such buttons on its touch control panel), not to mention dedicated popcorn, beverage reheat, minute plus, etc. Those mid-seventies Amanas with digital controls had circuitry that was state-of-the-art at that time, but which would be considered horribly outdated and obsolete.

BTW (2) : Microwaves with spring-wound dial timers can be had for almost ridiculously low prices these days. For someone who rarely uses a microwave oven, these are good, I guess, but for anyone who puts their oven to daily use, I'd suggest getting a digital model with touch controls. These aren't terribly expensive anymore (just a bit more than the analog ovens) and will last longer. The dial timer will eventually wear out in any of today's analog micros; in fact, it wouldn't surprise me if the magnetron outlasts the timer in these cheapies.

Jeff Strieble, WB8NHV (email addy not shown to deter spammers) Fairport Harbor, Ohio USA

I bought a Sharp with the auto sensor. I highly recommend this model. The Panasonic with variable power is nice but prone to failure and the combination convection/microwave is a PITA to keep clean - buy a separate convection oven.

High cooking speed does not mean they were leaky. Commercial microwave ovens are readily available with the same 1200W power rating. We had a

1200W Litton MinuteMaster for decades that would nuke a hotdog in 8 seconds flat. After many years of using that as a kid I've still got eyeballs and no extra appendages.

We dont have Amana Radaranges here, so I'm talking early 70s nukes generally here...

Carbon loaded rubber seals instead of modern choke door frames meant much greater susceptibility to leakage. These oldies should, if used at all, be leakage tested regularly.

Interlocks are the big safety issue. Modern ovens have 2 independantly operated switches which apply a short across the mains if either switch fails. Early 70s stuff didnt have that setup, just one switch failure and you're cooked.

The worst models I've seen actually cooked with the door partway open due to poor interlock design and misalignment, which is prone to occurring.

Then theres the final safety issue of uneven heating. This causes cases of food poisoning when cooking meat. In this respect nukes have come a long way since the early 70s.

Is the radarange one with an open downwards door? If it is, thats a safety issue too to some extent.

Its upto the OP of course, but if I had one that old I'd replace it. Its the interlock issue that would concern me, have seen too many machines with a bad switch go through the shorting trick to want to trust a machine with no such protection.

NT

The one I saw in Alaska had a microwave built into a regular oven (in a stove). Scared the crap out of me when I looked at how poorly the door fitted.

The Amana ovens were top of the line, the Rolls-Royce of microwave ovens. They were built like tanks, most had stainless interiors and real glass windows in the doors. They were the first on the market and real commercial quality units, my grandparents had one of these they paid a small fortune for in the early 70s. I believe all microwaves sold in the US have had multiple interlocks since the very start.

Thats something the OP could tell us, whether there are 2 sticky out things on the opening door edge or one. Older interlocks on the hinge side were not safe.

NT

IME as long as they are not flush, most any screw can be persuaded out with a good heavy pair of side cutters. Get a firm grip and use a screwdriver as a lever.