Phrazemaster said:
Just a question. I'm gathering parts for an LA2A build, with one of Rainton's excellent chassis - when he has them in stock again. I've gathered the input/output transformers, and I'm sourcing other parts slowly.
I'm having a bit of trouble finding the right rotary switch for the GR/-4/+10 section. Of course there's the one from StudioElectronics but as you may know it's $72.
http://www.studioelectronics.biz/sunshop/index.php?l=product_detail&p=4287
I'd like to stick with a ceramic rotary. I've found tons of them on eBay. But I can't seem to find a 3 position 2 pole switch that is a 45 degree angle turn.
I've been hunting for the same parts, and I have a couple of observations related to the switches on ebay, that may help.
The series of vintage Centralab switches I see most commonly are the PA-1000, PA-2000, and PS-100 series. PA-1000 and PA-2000 are the same size and features, except PA-1000 use phenolic wafers, and PA-2000 ceramic, so if you want to stick with ceramic, PA-2000 is the way to go. The PS-100 series are subminiature ceramic, and a little less flexible. Most of these have 30 degree detents, but there are a few variations that use 60 degrees.
You may be aware of this, but one useful thing about both PA series is that they have a movable stop that allows you to use them "up to" a maximum number of positions, limited by the physical contacts on the wafer. So, if you find a two pole six position (PA-2003, for example, with one deck that has two poles, up to 6 positions each), it is often listed as "2-6 positions," and then for the LA-2A, you would set the stop to only use the first 3 positions.
The PA-2003 is a single deck with two poles on it, but we could also probably use a PA-2005, which has two decks with 12 poles each, and still just set the stop to allow the first 3 positions ("wasting" 9 positions on each deck, and assuming a two deck switch will fit behind the faceplate without bumping into any other internal components, which I haven't confirmed).
The PS series are sub-miniature ceramic, and as far as I know, don't have the movable stop, so in that case, we would need a fixed three position switch, like PS-109, which is 3 poles / 3 positions (and just ignore one of the poles).
The other thing you can even do, if you want to get really creative, is modify a switch with more decks by removing decks. Usually switches with more decks are a lot more expensive, but I've sometimes found them cheap in surplus stores (where ridiculously large assemblies sometimes seem less useful), and they are pretty easy to disassemble. For the LA-2A, with limited space inside, you might have to actually use a dremel cut-off disc or something like that to shorten the central flatted shaft that indexes to the contacts on each wafer, plus switch the screws the hold the decks together to be shorter, but it might be worth the hassle if the price is right.
. Unfortunately, I'm not able to build it because I'm selling to raise money for something personal that's happened to us. So, I'm selling the case, which is mint condition, and as mentioned has a certain logo on it and the case looks perfect. I've also got a NOS UTC A-10 transformer and a NOS Triad power transformer still in the original box. I'm just selling them for what I paid for them. Just PM me. I'm posting this in the black market section also. If this isn't an appropriate place for it please delete the post.
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