Wow, don't know how I missed page 4 with all the great pics and information yesterday. Congratulations Bob and John on the first rebuild of a 15GP22, and best luck with the Mitsubishi!
Cliff

"What's the matter, Sir Guy? Run out of hangings?"

"I know a ripe subject for one!"

Love the "Adventures of Robin Hood" still.

Great Job. Congrats to You Gents.

Lee J Barmakian:smoke:

Hey Guys,

Just got caught up on my VK viewing. WOW! super kudos to both of you and Scotty as well.

Persistence does pay off.

-Steve D.

Cudo's to everyone involved in this project! Your persistence has really paid off.

Not to put a wet blanket on this, but isn't Scotty supposed to be retiring like really soon? Is this something that might be transferable to the equipment at the ETF?

Darryl

OMG let's not even think about this. If it doesn't get mentioned, then hopefully Scotty will forget all about retiring!!

In discussions with Scotty, this does not appear to be a stumbling block in terms of likely 15GP22 rebuilds. However, there's never a guarantee, and my information is months old.

Pete

First, thanks to all the kind words from the VK community. It has been a long road to this first successful rebuild. But it has been a lot of fun getting there.

Scotty is not likely to retire in the near future (months/year), but several years out is anybody's guess. And Scotty may not the the short pole in the tent. The era of he CRT is coning to an end, and our stem supplier or the vendor who replaces the cathodes and filaments in the gun and remounts it on the stem could go away at any time. And Bob's EDM process is vital to having guns rebuilt as well.

So Bob and I are going to attempt a couple of more under vacuum rebuilds, and Bob is going to try a leaker tube using his sealing protocol. We will attempt to do this in as timely a manner as possible.

Depending on the results, we will then consider the path forward. More to come......

this process must be perfected and carried on into the future.congrats on rebuild.i hope this is the first of many to come!

This is truly amazing. Excellent work guys!

I assume that you've come up with a sealing method to prevent the newly rebuilt tube from leaking, correct? That was the major achillies heel of the 15GP22 in the first place - faulty seals letting all the vacuum out.

I'm really interested to see how a rebuild goes on a tube that's already up to air (i.e. most of the other 15GP22's). In theory, since the guns are getting rebuilt, it should work - the stumbling block being possible phosphor degredation due to oxidization over the years.

-Ian

Ian,

There is no verified method for preventing rebuilt tubes from developing a leak, or for stopping the leak in a tube so it can be rebuilt. If our leak mitigation protocol works out, then the answer may be "yes".

The tube just rebuilt (a non-leaker) was treated with vacseal. Of course, we will never know if it does any good, we can only know if it does not.

Congratulations on the effort. You took off with the ideas and support of the community and landed safely. Just passed your check ride. Nice to see a really great picture! Of course, it's understandable rebuilding 15GP22 that old might only last a month, a year, or maybe the next 50+ years. At least, knowledge and practical skills have been demonstrated. This is definitely worth celebrating !!!! :thmbsp:

Im speechless! Bravo gentleman!! This is truely an amazing breakthrough!

I was able to visit John and see it in person, very impressive picture indeed.

:yes:

Update: 11/21/09
 

Just a note to let you know we aren't sleeping on the job.

Over the past couple of weeks since our initial success, John and I have been collecting and preparing 15GP22 electron gun asemblies.

John removed, and contributed 4 gun assemblies from his crt stash, and I was able to contribute 3 from my stash.

Yesterday I finished the EDM processing of the last gun and all seven guns were shipped to the gun rebuilder for eventual instalation of new cathode assemblies and mounting on new stems.

We have ordered a second batch of stems from the stem manufacturer, and we have a production date of about December 15th.

We have instructed the gun rebuilder to rebuild 3 more guns and mount them on new stems. Those guns will be shipped to Scotty when finished. Scotty has 1 rebult gun in his possession already, so we will have a total of 4 guns on the next trip to Hawkeye. We have not set a date for that trip yet, but we are hopefull that it will happen in December.

We will be rebuilding 2 under vacuum 15G's and preparing a couple leakers for some High Vacuum leak experiments that we will be conducting with John Yurkon at his facility.

We are very excited to be working with John Yurkon. He is making available to us, High Vacuum scientific equipment at his facility, that will hopefully be able to tell us if sealing the leakers is feasable. By using the instrumentation in John Yurkon's lab, we should be able to determine if we are able to seal the crt's do a degree that will hold a long term vacuum. The only other way to determine if we can seal these tubes would be to actually rebuild and seal some tubes, and then wait to see if they leak. That could take anywhere from hours to many years. In John Yurkon's lab we should be able to detect the degree of leakage before and after we seal a tube, to determine if the sealing method we are using is successsful. John Yurkon works in an ultra high tech scientific facility that makes targets for use in a linear accellerator at the National Super Conducting Labratory in East Lansing Michigan. Here is a link to their web site. http://www.nscl.msu.edu/

We can't begin to thank John Yurkon enough for his assistance in this project. With John's help we should be able to determine if sealing the leakers is possible or not.

Bob

This is simply incredible!