Bent tube pins

[drew]

I bought a Hammond organ amp from an ebay seller who apparently interpreted my instructions to take precautions to avoid damaging the tubes in transit to mean "put the entire amp, with the tubes in their sockets, in a soggy cardboard box, add 25¢ worth of bubble wrap, then send it cross-country." Asshat

It arrived with the chassis bent, and sitting atop one of the (luckily shield-encased) pre-amp tubes, the other pre-amp tube rolling around loose, and the EL84 power tubes partially in their sockets, but bent down, as if a great weight had been placed on top of the flimsy box. Which it undoubtedly had.

The tubes appear to be intact, but their pins are bent to varying degrees. I don't have much experience with these things; is it safe to try to carefully straighten them with needlenosed pliers?

[skyboltone]

That's just about your only choice Drew. Go slow and keep the movement where the pin enters the glass to a minimum, even if that means two sets of needlenostrils. I've been fooling with one of those little guys for quite awhile and there are various pictures and diagrams posted in this section about it. I did make a garolite eyelet board for it based on the Matchless spitfire but ended up wiring it point to point anyway. It's pretty tight and creates lots of problems for any kind of gain at all. I recommend you take your iron and build in a new bigger chassis.

What are you gonna do with it? Oh, I got an AO-35 empty chassis if yours can't be straightened. It is truely empty, just steel and holes.

Dan H

[drew]

Probably going to make a Lite IIB out of it. A guy on 18watt.com posted a layout for rebuilding the AO35 board as the Lite circuit.

[lastwinj]

i hope you left negative feedback.


germ

[Funkalicousgroove]

There is such a thing as a pin straightener, call Fat willie(lord valve) he sells them. 303 778 1156

[Dai H.]

IMO pin straighteners are a BAD idea, since they seem to create the situation where too much pressure is put on too many points on the glass and this leads to cracking. I've cracked a number of tubes on a TPS myself which is why I'm speaking about this. I think it's safer to bend one pin at a time, gently and slowly. I've used a hollowed out ball point pen and pliers (the kind with no whatchamacallits--serrations? or teeth). Worst case using the ball point pen was a broken off pin (when the pin was extremely bent)--but the tube still worked. Later, I got a TPS thinking, "obviously this has to be a better purpose built tool), but I cracked a bunch of tubes on it (which makes you feel extremely ill when it happens, lol...). Now some tubes didn't crack and survived, so I gather it can depend on how bent the tube is and differences in the construction (thickness of glass?), but I'm not taking any more chances with mine.

[rfgordon]

If needle nose pliers are too fat for ya, use surgical hemostats. I use them all the time. Call your local hospital, to see if they sell/give away used surgical instruments. Thats how I got my 3 pairs! Since they lock closed, they're great for sticking wee parts into wee eyelets. I use both the curved and the straight kind. I find they make bending delicate leads more controlled and delicate.

[Funkalicousgroove]

Dai,
I think your experience with the Pin straightener may have been user error, I've been using one for years without one casualty, just make sure your pins arent WAY out of whack, If they are I use the teeniest pair of needlenoses I have to bend the offending pins back to where they'll go into the holes in the straightener, then I use the straightener.

[Dai H.]

They didn't come with any instructions, so I suppose that is a possibility. I just put the tubes in and pushed slowly. Pins that are really bent--I would think they wouldn't even line up with the holes in the straightener (but I'd have to go look at mine to be sure). I think really tight sockets can also be a danger to tubes. Seems to be basically when you don't have enough "play" it can put too much pressure on a tube base and envelope (which are usually glass). (As an aside, I like to put in a dummy plug in a socket when soldering wires and parts to it--my thinking is this will help ensure the amount of "play" is the same with or without a tube inserted.) Rough handling could also be a problem too though with tubes, since they are after all made of glass (at least a lot of the time).

[Funkalicousgroove]

I had the benefit of having Lord Valve Show me how to use it, otherwise I may have screwed some up myself. It also helps to use a bit of lube (de-oxit works fine) push slowly, twist and manipulate as needeed, and keep a watchful eye.

Dental picks work well for loosening/re-tensioning your sockets. I just have a Junk tube that i use the first time, then I put the good tube in.

[Dai H.]

I might be wrong, but it still seems too risky. Could've been I needed to use lubricant or something, but it seems to be there is only way the straightener could be used. I'm seeing it sort of like levers, where the stick is the pin and the hole of the straightener is the fulcrum, and when you put multiple pins in multiple metal solid holes with no give and apply the force, it puts too much pressure on multiple points on the tube base. Not all tubes cracked, but some that didn't have particularly bent pins did. I just think there is less risk when applying force to one pin at a time rather than many. But again, maybe my thinking is wrong (I'm no engineer or anything) and it'd be nice if someone with more technical understanding could explain what is and what isn't going on.

[Funkalicousgroove]

Could be the straightener itself as well. To each their own, i use mine all the time though.

[PRR]

Straighteners are fine for those slightly-bent pins you can't fit in the socket in the far corner of a TV set. Time is profit and if you can correct the pins with a 9-hole tool you get paid and out the door faster. I may have one, but have not used it in decades.

If pins are really bent, put on some glasses and use the needlenose pliers. Be gentle, and don't stress the seal. But if pins are really bent, they may already be micro-cracked in the glass, and you are going to lose the bottle anyway.

There's some knack, but a lot of luck.

Hemostats are often available in hard-core drugstores, the kind which rent wheelchairs and sell colostomy bags. The cheap asian junk is low-price. I prize my US-made forceps from the 1970s. Great roach-clips.