Removing Large Glass Tubes

[ka4koe]

Transmitting Tubes

[Ralph W3GL]

That SB-220 need a new set or just spares ?

[ka4koe]

Nope. Not yet. Spares go bad if you don't rotate them.

[Jim, W5JO]

Nope. Not yet. Spares go bad if you don't rotate them.

I don't think so.  I have seen tubes of that type that sat in boxes for over 10 years then installed without issue.  

[W7TFO]

Nope. Not yet. Spares go bad if you don't rotate them.

I have found it all depends on how well they were made.  Some NOS tubes (big ones, too) I have are over 80 years old now, still as hard a vacuum as you could want.

Once I test them here, they go on the shelf waiting for a project.

I've got some new jobs and found them gassy out of the box.

Buying tubes is a crapshoot, just try to keep it off yourself .

73DG

[W2VW]

Nope. Not yet. Spares go bad if you don't rotate them.

I don't think so.  I have seen tubes of that type that sat in boxes for over 10 years then installed without issue.  

I agree. I've owned several that were wrapped in newspaper with Watergate headlines.

They fired up just fine.

I believe the issue is hamateurs who didn't understand they need to run orange once in a while along with some bad batches.

[Jim, W5JO]

Nope. Not yet. Spares go bad if you don't rotate them.

I don't think so.  I have seen tubes of that type that sat in boxes for over 10 years then installed without issue.  

I agree. I've owned several that were wrapped in newspaper with Watergate headlines.

They fired up just fine.

I believe the issue is hamateurs who didn't understand they need to run orange once in a while along with some bad batches.

Most of the problem with glass tubes is some people do not know how to insert or remove them.  They rock them back and forth to remove them from the socket or do the same to insert the tube.  That causes stress where the pin exits the glass which causes minor cracks that expand as the tube is heated and cools.

That is part of the reason manufacturers put ceramic bases on some of them like the 4-250, 4-400 and up.  That made them a lot more sturdy for people who did not understand what they are doing.

Unless there is a bad run, gas in tubes almost does not exist and if you follow the manufacturer's installation directions you will not have a problem.  

[W2VW]

A guy in my neighborhood sells a lot of pre-owned ham gear.

There was this guy who purchased an L4B from him and removed the tubes. For some reason he decided to test the tubes by shaking them violently.

We found this out when we all met at guy#1's house to test the tubes that had been removed.

Tube shaker guy writes a lot of stuff appearing on ham websites.

[Jim, W5JO]

Tube shaker guy writes a lot of stuff appearing on ham websites.

Oooooooouch.

[K1JJ]

Jim said:

"Most of the problem with glass tubes is some people do not know how to insert or remove them.  They rock them back and forth to remove them from the socket or do the same to insert the tube.  That causes stress where the pin exits the glass which causes minor cracks that expand as the tube is heated and cools."


Interesting.

What is the best way to remove a tube that is "stuck" or not coming out easily when pulled straight up?  

Does this apply to both smaller tubes and larger transmitting tubes?

The leverage is greatly increased by rocking and non-existent when pulled straight up, so I can see why rocking the tube becomes a natural, though stressful, way to do it.

T

[Jim, W5JO]

Interesting.

What is the best way to remove a tube that is "stuck" or not coming out easily when pulled straight up?  

Does this apply to both smaller tubes and larger transmitting tubes?

The leverage is greatly increased by rocking and non-existent when pulled straight up, so I can see why rocking the tube becomes a natural, though stressful, way to do it.

T

If a tube has seized in the socket, it may need to be rocked gently to free the pins, but after they are free, I pull straight up to remove the tube.  Most problems occur when the pins are sufficiently above the socket where leverage can be exerted on the base junction.

I have also seen problems with tubes that have the plate pins exiting the bulb on top.  If one is not careful they fracture easily especially the 829 and 5894 types that have thin envelopes.  Small receiving tubes rarely are subjected to operational conditions that cause the pins to seize and the miniature types have pins that are a lot more flexible so rocking has never been an issue for me.  It is just those darn expensive transmitting tubes that I worry about especially now that prices are astronomical.

[K1JJ]

If a tube has seized in the socket, it may need to be rocked gently to free the pins, but after they are free, I pull straight up to remove the tube.  Most problems occur when the pins are sufficiently above the socket where leverage can be exerted on the base junction.

I have also seen problems with tubes that have the plate pins exiting the bulb on top.  If one is not careful they fracture easily especially the 829 and 5894 types that have thin envelopes.  Small receiving tubes rarely are subjected to operational conditions that cause the pins to seize and the miniature types have pins that are a lot more flexible so rocking has never been an issue for me.  It is just those darn expensive transmitting tubes that I worry about especially now that prices are astronomical.

Yes, very expensive, like a new 4-1000A costs $2,000 at Richardson these days...  


What sometimes scares me about pulling a tube straight up is the grip we need around the glass body. I sometimes wonder what would happen to my hand if the glass collapsed.  But in reality, I'll bet even with leather gloves I don't have the strength to crush a 4X1.  

The 4X1 has a strong ceramic base, but I plan to be more careful in the future when pulling them out. I tended to rock them gently. Overall, it seemed like the least stress was to rock, but I can see it was not.    It also depends upon the mechanical structure of the socket pins. Some of the new Chinese sockets have little give and are a bigger risk - while the older Eimac seem very springy in comparison.


Yes, top tube plate caps can be fragile. I've had one or two 811A/6146 type-tubes lose their glue and fall off, even though the pin and seal was OK. I epoxied them back and all FB.    The main thang is to use a very flexible plate lead that puts no mechanical stress on the tube cap. I am very anal about this and always use a flexible buffer between the cap and any copper strap to the plate.

T

[Jim, W5JO]

If a tube has seized in the socket, it may need to be rocked gently to free the pins, but after they are free, I pull straight up to remove the tube.  Most problems occur when the pins are sufficiently above the socket where leverage can be exerted on the base junction.

I have also seen problems with tubes that have the plate pins exiting the bulb on top.  If one is not careful they fracture easily especially the 829 and 5894 types that have thin envelopes.  Small receiving tubes rarely are subjected to operational conditions that cause the pins to seize and the miniature types have pins that are a lot more flexible so rocking has never been an issue for me.  It is just those darn expensive transmitting tubes that I worry about especially now that prices are astronomical.

Yes, very expensive, like a new 4-1000A costs $2,000 at Richardson these days...  


What sometimes scares me about pulling a tube straight up is the grip we need around the glass body. I sometimes wonder what would happen to my hand if the glass collapsed.  But in reality, I'll bet even with leather gloves I don't have the strength to crush a 4X1.  

The 4X1 has a strong ceramic base, but I plan to be more careful in the future when pulling them out. I tended to rock them gently. Overall, it seemed like the least stress was to rock, but I can see it was not.    It also depends upon the mechanical structure of the socket pins. Some of the new Chinese sockets have little give and are a bigger risk - while the older Eimac seem very springy in comparison.


Yes, top tube plate caps can be fragile. I've had one or two 811A/6146 type-tubes lose their glue and fall off, even though the pin and seal was OK. I epoxied them back and all FB.    The main thang is to use a very flexible plate lead that puts no mechanical stress on the tube cap. I am very anal about this and always use a flexible buffer between the cap and any copper strap to the plate.

T

I always try to grab a tube as low on the envelope as possible to help with the breaking problem you fear, and for good reason.  I also use leather gloves or a doubled towel.  That ceramic base was added to prohibit some of the problems of micro cracks and helps immensely.  But even with the ceramic base, considering the cost of high power tubes, I try to be as careful as possible as you so aptly state.

In short, the less stress and shaking that happens upon insertion or removal of the tube is much better for it.  But, as to the original comment, I have never had a high power tube fail to operate correctly due to gas in the envelope.  People who are neophytes about high power tubes should read about the procedure to start them in service by the manufacturer rather than unwashed comments.  They are different for tubes with different types of filaments and anodes.

I doubt seriously anyone with a lot of experience were unaware of potential problems but I have seen all types.

[Opcom]

I invented a puller for big tubes like the 3-500 and 4-1000. I could not get it patented. Probably a moot point now. Just a strap of fiber reinforced, low dielectric K, 0.010 thin, strong, plastic-like material composite having some holes in the right places for air that was laid down and then the tube plugged in. To remove, attach the long 'ends' (straps) to the installed piece and pull straight up, using the other hand to steady the tube so it doesn't pop up from the socket and bust. It was designed for HF, maybe 6M. At the higher VHF range its small dielectric constant might affect grid tuning slightly (not tested). The socket cylinders on the 4-1000 air system socket are free to move a little. It makes it less stressful on the tube IMO.

[WQ9E]

Always use proper leather gloves and safety glasses when removing these large tubes.  It is very rare for one to fail but the implosion is impressive and rocking one can pop a seal causing instant destructive failure rather than the more typical slow leak.  It may sound like overkill but safety equipment is like insurance, by the time you owned it the time is too late.  There was an article in one of the 1950s service magazines about a tech who did a near complete amputation of his thumb trying to pull a stuck 7F8 (loctal) tube out when it shattered.  If a little loctal can do that imagine what a 4-400 or 4-1000 would do.

If a large tube is really stuck do the smart thing and use one of the penetrating agents on the pin/socket interface (but no overspray) and let it sit awhile.  The extra time spent doing this could easily save a very expensive tube.  Later 3-500Z production from most manufacturers added an additional base support (like the photo show by the original poster) which both reduces the stress on the pins and provides some elevation so the simple fan cooling system like that used in the SB-220 and Drake L-7 can better cool the base seals.  The earlier 3- series is very easily damaged by rocking.

[W2VW]

Fresh DOT-3 automotive brake fluid applied with a Q-tip works great for dissimilar metals binding. Use sparingly and keep away from paint.

[Jim, W5JO]

Replacing them in a BC station doesn't always allow time for chemicals to work.  Every minute of silence costs money and the same for the old IMTS base stations.  With ham radio you can get away with delays, but commercial service has a different set of demands.

[W2VW]

That broadcast stuff sounds like serious business Jim.

[Jim, W5JO]

That broadcast stuff sounds like serious business Jim.

Silence is not acceptable in the BC industry nor when all you  have to sell is airtime.

[Opcom]

Always use proper leather gloves and safety glasses when removing these large tubes.  It is very rare for one to fail but the implosion is impressive and rocking one can pop a seal causing instant destructive failure rather than the more typical slow leak.  It may sound like overkill but safety equipment is like insurance, by the time you owned it the time is too late.  There was an article in one of the 1950s service magazines about a tech who did a near complete amputation of his thumb trying to pull a stuck 7F8 (loctal) tube out when it shattered.  If a little loctal can do that imagine what a 4-400 or 4-1000 would do.

If a large tube is really stuck do the smart thing and use one of the penetrating agents on the pin/socket interface (but no overspray) and let it sit awhile.  The extra time spent doing this could easily save a very expensive tube.  Later 3-500Z production from most manufacturers added an additional base support (like the photo show by the original poster) which both reduces the stress on the pins and provides some elevation so the simple fan cooling system like that used in the SB-220 and Drake L-7 can better cool the base seals.  The earlier 3- series is very easily damaged by rocking.

Safety can't be over emphasized. People think the danger is turned off with the high voltage. When I was a kid, I used to recover monochrome CRT phosphor. In those days, old TVs and large parts were often piled up behind the shops in the rural areas until a truckload was accumulated for the dump. The tubes had to be broken in several stages to leave mostly the faceplate but there was left still a sharp edge all the way around the faceplate; the root of the bell. After 40 years there is still a mark on my palm from a deep cut that should have been stitched. I was more concerned with not being found out for a foolish activity by my father than with enduring the stitches.

[WQ9E]

A guy in my neighborhood sells a lot of pre-owned ham gear.

There was this guy who purchased an L4B from him and removed the tubes. For some reason he decided to test the tubes by shaking them violently.

We found this out when we all met at guy#1's house to test the tubes that had been removed.

Tube shaker guy writes a lot of stuff appearing on ham websites.

Looks like this one failed to survive the "shake test"    

http://www.ebay.com/itm/Eimac-4-400A-Electron-Power-Amplifier-Tube-/221398494319?pt=Vintage_Electronics_R2&hash=item338c60ec6f

[W2VW]

A guy in my neighborhood sells a lot of pre-owned ham gear.

There was this guy who purchased an L4B from him and removed the tubes. For some reason he decided to test the tubes by shaking them violently.

We found this out when we all met at guy#1's house to test the tubes that had been removed.

Tube shaker guy writes a lot of stuff appearing on ham websites.

Looks like this one failed to survive the "shake test"    

http://www.ebay.com/itm/Eimac-4-400A-Electron-Power-Amplifier-Tube-/221398494319?pt=Vintage_Electronics_R2&hash=item338c60ec6f

The seller is selling the plate cap in another auction. He may list the vacuum in a third auction next week.

[Steve - K4HX]

Maybe he'll sell code tapes in another auction.

[WQ9E]

The seller is selling the plate cap in another auction. He may list the vacuum in a third auction next week.

That explains why he states in the auction for the tube, "Sold As is, No way to test".  I guess he needs to reinstall the vacuum and superglue the cap back in place so that he can test it. 

I guess it had to happen with all of the guys parting out radios on ebay now someone is parting out tubes.

[Jim, W5JO]

Spider tat2man?  wonder if it comes with a gift certificate to the nearest parlor?