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Old 01-30-2008, 11:18 AM
RetroHacker RetroHacker is offline
Electronics Accumulator
 
Join Date: Jan 2005
Location: Niskayuna, NY
Posts: 464
OK, so the heat will melt the goo. I wasn't sure what it was - if it was RTV that was added later, then I don't think the heat would have helped. So that was factory goo... I think next week I'll try again to get the glass off - I think if I use the floor tile puller and a hair dryer I should be able to get it off. Thanks Gilbert!

I went down to the library and photocopied the Sam's. This is a complicated set - biggest schematic I've ever seen in a Sam's. It's longer than a standard 11x17" page. Now I have a list of the capacitors it uses, so I can order the ones I'm out of. Some values are going to have to be substituted though, since even Mouser doesn't have some of them (like .0027 and .0039 at 1600v). And as usual, electrolytics are only going to be able to be "close" since the industry standard has changed to a new value convention - like 47uf instead of 40uf. Fortunately, the component tolerances with these old parts is pretty wide, and small changes won't matter. Either way, I'm going to try and keep as many of the components the right value as possible.

In some cases, I wonder why they even bothered. I mean, why have both .0022 and .0027 caps in the same set? There is a good chance that they'll be the same anyway, with the 10 or 20% tolerance on these old style paper caps. That's the whole reason for the modern standard value system in the first place, but you would think that back then, someone at RCA would have said "Gee, if we only use .0022's and forget about the .0027's, the circuit won't actually really change, and we'll have one less part to stock".

It's kinda frustrating to not be able to get exactly the right parts, and, even though I know what I can safely substitute, I like to try to keep things the way they were when possible, and use original values - if only because it makes tracing things later so much easier because the values you're looking at in the set are the same as on the schematic.

The electrolytics are going to be fun. Lots of substitution and creative mounting.

-Ian
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