[mandh]

I recently picked up a Model 40-190 and found that I could not remove the loctal tubes from their sockets so I could test them. When a little prying with a pair screwdrivers did not work, I found that putting a little light oil or WD-40 on the loctal key did the trick. After the oil flowed into the key, the tubes came out with only hand pressure. When I got the tubes out, it did not look like there was corrosion on the key pin so I guess the oil just reduced the effort needed to remove the tubes.

[codefox1]

There is a little nib or protrusion on the base of every loctal tube, If you rock the tube in that direction, it should come out without damaging the tube or the socket. Most of these tubes have been in their sockets for a real long time. The Wd40 probably helped by loosening oxidation on the center pin, and everywhere else. There might also be some gummy wax from a "condenser" that has flowed into the tube socket and formed a bond between the poor tube and it's socket. Sometimes there is a powdery yellow crud on loctals, don't know what it is, but have seen it many times even in NOS tubes in the box. It seems to be solvable in oil or paint thinner. Just make sure you blot all the residue away before reinserting the tube and firing the set up. I usually brush on a little paint thinner on the socket and the tube base, scrub with an old tooth brush, give it a shot of deoxit, blot it with a paper towel, and let it dry overnight. Beware, the decals and hense the tube numbers are fragile, unless they are etched on top, and don't count on it, so you might lose the markings when you clean the tube. Remember and mark which one goes where if you remove more than one tube. I found out that windex will remove everything, but paint thinner usually does not remove the decals, but is slow to to remove the other grunge.

Insert a loctal tube straight down once you have indexed the tube in the socket.

Perhaps there is a chemist on board who could teach us all how to properly clean and restore the pins on loctal tubes. I understand thay are a special breed.

[etech]

There is a little nib or protrusion on the base of every loctal tube, If you rock the tube in that direction, it should come out without damaging the tube or the socket.

This is true. Many people are unaware that the loctal tube is locked in the socket, hence the name 'loctal'.

FWIW, it is absolutely necessary to tilt or rock the tube in the direction of the 'nib' to unlock and remove the tube without damaging the socket.

Best regards,

Ed

[exray]

FWIW, it is absolutely necessary to tilt or rock the tube in the direction of the 'nib' to unlock and remove the tube without damaging the socket.

Best regards,

Ed

Egg-zactly! I ruined a few sockets before I learned that! Haven't found a ' stuck' loctal tube since then.