Jerry's "Gonna Rebuild me PLWO 1000" thread

[jbeckva]

Ok, so I am going to see about taking the PLWO 1000 Lee built for me, and rebuild it with all the "tricks" Mr. Lee "a-learnt" since then.

One thing that has me concerned is how we did have that one emitter resistor disconnected, so the first thing I'd like to do is just "verify" all of the outputs. Might go ahead and replace all emitter resistors if need be (Lee.. how old were those, do you remember?)

Back to the outputs... So 'ey Lee.. what am I looking for there? What's the best way to make sure they're all still up to snuff?

The other thing is that I'm going to go ahead and get those connector blocks for the main and dc boards, and rewire.

Hmm.. and go ahead and replace the level pots too (having them bypassed is making the amp too sensitive and more noise-prone)

And do the "star ground" wiring...

And a few other things.. maybe a fan assembly while I'm at it.

 

[Gibsonian]

My PL700's/1000's are dead quiet with bypassed pots. Not sure what is causing yours to be noisy.

 

[laatsch55]

Jerry those werew brand new 15024's and 21196's. I wouldn't think they are even close to needing swapped out. Those emitter resistors were put in 1972. Didn't I put some alps pots in that??

 

[jbeckva]

Jerry those werew brand new 15024's and 21196's. I wouldn't think they are even close to needing swapped out. Those emitter resistors were put in 1972. Didn't I put some alps pots in that??

The pots seemed to me to be original equipment i.e. old (I think??.. in any case they need to be replaced). Remember tho that one of the outputs essentially wasn't "in circuit" with the emitter resistor disconnected, so I'd just like to be sure about the others as they had to take the slack of it not firing on "all cylinders" - especially with "someone" wanting to make sure his ears were a-bleedin' with the K'horns before he sent it out.. heheh..

Hmmm... maybe the sockets too... do you think I should see about fitting it with new TO3 sockets?

How many of those emitter resistors and of what value? 2.2 ohms, something like that?

 

[laatsch55]

.33 on the plus side, and.27 non the minus Jerry I just bought over 300 to-3 sockets ./ I'll post a pic and you can tell me which style you like best.

8 of each, originals were 2 watty, 3 don't hurt nothin.

 

[laatsch55]

Here they are.

 

[mlucitt]

I like the one on the right, I dn't know why...

Make sure the .27 Ohm resistors are negative biased and the .33 Ohm resistors are positive biased, just look at the schematic and you'll see what I'm talking about.

 

[jbeckva]

I like the one on the right, I dn't know why...

Make sure the .27 Ohm resistors are negative biased and the .33 Ohm resistors are positive biased, just look at the schematic and you'll see what I'm talking about.

Re the one on the right.. is that because there are no mods needed to the chassis whereas with the others, there may be?

So the .27's are for the negative rail and the .33's are for the positive rail? What's a good source for these if I were to go with the more modern non-carbon types?

 

[mlucitt]

Mouser is our go to source. Look under P/N 71-RS2B-0.27 and 71-RS2B-0.33.

 

[Gepetto]

The first on the left (green) and third one from left (black) look like the best sockets. Very similar to a stash of mil spec sockets I acquired a long time ago stamped with a CEBY mark on the metal part. Nice sockets.

 

[laatsch55]

Amen Joe. I did my son's 400 with the black ones, no mod needed Jer, and the green and black ones take a 6-32 machine screw so you can run allen heads and be a lot more precise on your pressure.

 

[jbeckva]

That's cool. So I looked on Mouser for the resistors, but the .27's have a 6 week non-stock lead time. I can find 5 percenters, but no 1 percenters so far. The greenies will work. Do they still make the silicon insulators instead of mica's? I always preferred the silicon's back in the Nav days when working on those old S3 tacco/senso scope cards.

 

[speakerman1]

Amen Joe. I did my son's 400 with the black ones, no mod needed Jer, and the green and black ones take a 6-32 machine screw so you can run allen heads and be a lot more precise on your pressure.

Do you know what the standard torque on a screw is?

Larry

 

[laatsch55]

7 inch ounces.

 

[jbeckva]

Heh.. I always thought it was "just nuff to hold that bugger in place" ??

 

[speakerman1]

Ours were set at 8 in lb. Get a lot more on an allan head. They make screws that you can't over torque. They strip out 1st. PIA Plus they were titanium. Not fun to drill you can eat up some resharpened drill bits. Set our screw guns on 2. Get really close.

larry

 

[jbeckva]

Ahh flashback of ARC-161 HF amps ... they had like ... 20 or so of those dang allan heads you had to torque down.

 

[speakerman1]

Man we depaneled or paneled a plane. We had at least 20 mechs per shift and we would have a week. Plus interior , cockpit gutted. Engines off. There is nothing left that you couldn't get to the interior skin to inspect.. The Insp. would still be inspecting and we would be right behind them putting it back together and fixing. If you burned cards you got no breaks; but scheduled breaks. I took breaks when I wanted. My boss was right there with me what could they say. LOL

 

[laatsch55]

Check with wattsabundant, he just scored 50,000 silpads.n

 

[laatsch55]

So, what all ya plannin to do Jer??