Loose tube Sockets and retensioning and cleaning versus replacement?

[Sleet]

I've been wondering about the effectiveness of tube socket retensioning. Is this always a short term fix? If a power tube or rectifier tube are loose to the point where they are almost falling out of the socket is it time for replacement?

A few other questions. What brand of tube sockets do you use when replacing? Is effective cleaning of the sockets possible? I was reading about Stabilant 22A and how this can be used to remove oxidation and corrosion on metal contacts (pricey!).

[Enzo]

Tightening tube sockets is not about how the pins sit in the holes, it is about how the female pins GRIP the tube pins. We want to close up the opening in each female to insure better grip. I tighten socket pins routinely and have never had one come back later.

It is OK if the female pins wiggle around in the socket body. They are then free to line up with the tube pins more readily, when you shove the tube into the socket.

I sometimes use contact cleaner, sometimes Deoxit, and sometimes simple friction. Most times just pulling a tube out and pushing it back into a socket refreshes the contact surfaces.

I am not very brand conscious about sockets. I try to match the appearance of the rest of the sockets. I prefer to replace a ceramic with ceramic rather than have five ceramic and one phenolic socket in an amp chassis. I have no complaints against the Belton sockets so many amps use.

[Sleet]

Thanks Enzo,

Just to follow up, is the most common reason to replace a tube socket arcing or burning of the female pins?

[Enzo]

I have no idea what is more common. Anything that is wrong indicates replacement, regardless of how common.

PIns break off the socket, pins break within the socket, sockets arc leaving a conductive burn mark across the body, on smaller sockets clumsy solder work can wick solder up into the pin filling it. Sockets can get physically damaged or cracked. Pins can corrode beyond cleaning. I am sure there are other good reasons.

[nevetslab]

On Power Tubes, there are generally two types of contacts: Forked (flat or wavey-metal forks) or wrap-around (folded metal into tensioned triangular sockets). I prefer the socket style, which over time are much easier to re-tension with a very tiny flat-blade screwdriver down the socket body's throat (All power fully discharged) There are cheap sockets out on the market, usually reflected by their selling price. Those cheap ones don't retension....re-insert the tube, and the contacts are loose again. Those I replace, if they're causing trouble.

On Fender chassis's like Twin Reverbs, and the like, over time, the power tubes seem overly loose, and some tubes, when fully inserted, still don't fully seat into the sockets, so there is noticeable wobble. Usually if the spring-metal tube clamps will firmly grip the bakelite/plastic tube base, the looseness is mimized. Those clamps don't last forever, and I've had to replace them . There are a number of different clamps out there. I"m not sure what Mesa is using, but theirs feel likee the stiffest ones I've encountered...to the point to where they hurt your fingers while trying to depress both jaws to get the tube out (worse when hot).

When warranted, I'll install spring hold-down clamps to replace the 'bear-trap' base clamps, usually fitted with high temp silicon sleeving to keep the spring/clamp hat joint off of the tube glass. IMO, the hold-down clamps provide the best seating force on power tubes.

Trying to re-tension the forked tube socket inserts is a tooling challenge, since the tool has to be narrow enough to fit into the slot for the blade terminals, and be strong enough to use as a pr-ybar against the terminal-s socket wall I use a re-shaped Wiha 260/1.5 x 40 bladed screwdriver for those.

[Sleet]

Nevetslab,
Thanks for your input!

[Randall]

I use metal dental tools for retensioning sockets. They come in different shapes and angles and thicknesses. Sometimes they break, but they are cheap. My old dentist used to give 4 or 5 every so often.

[Enzo]

Those are great, I got some from my dentist too. Those giant baby pins, like for diapers, are hardened, so you can unbend one and use the point.