RACS status

[tubesrule]

There is an interesting thread on the UK forum about RACS:

"The signs now are that RACS is no longer trading. A contact tried to send them back a 'pattern' tube, supposed to be a mock-up for a new-build CRM121, and this has been returned to sender by the postal system."

This is distressing news but with the recent revelation that most tubes they were trying to rebuild were failing, it's not surprising. John F. can probably comment on where this leaves the 15G rebuild effort. Hopefully Jerome can jump in and give more information.

Darryl

The original thread can be found here:
http://vintagetvandradio.myfreeforum...p=52254#p52254

[Geoff Bourquin]

Is (was) this them? Domain is for sale
http://tube-cathodique.com/

[tubesrule]

Good catch Geoff. That was their website. I guess there is no doubt they are now, or will soon be gone.

Darryl

[John Folsom]

Here is the latest news from Jerome Halphen as of 17 April:

"Situation at RACS.

To make it short, they are discouraged. 4x 15GP22s have been 4 pass fritted, gettered and the neck sealed off without a gun. The tubes are in observation to assess if the fritting has really sealed the bulb/ultor assembly or if there is still leakage.

Ingo's #1 CRT, which had an unactivated restored gun mounted had to have it removed for a 5th fritting pass. The getter whitened after a 3 week observation round.

They are not optimistic. Their analysis so far is that the combination of 60 year old glass + the quite brutal stress of high temperatures + vacuum pumping creates new creeks (yes, creeks as in aviation turbine blades progressive metal destruction) and leakage points even if other ones have been sealed.

Their thinking right now is: "either we succeed with those first 4 or if the yield is too low we won't attempt the 6 remaining".

Concerning the other 8 tubes still in the US, after real long discussions they conceded they MIGHT be OK to do them, providing John Yurkon or Bob could send only the ones confirmed after testing as having no leaks or sealed with success in John's soon to be ready oven.

Philippe R. admitted that this behavior of new creeks, apparition of cracks or new leakage points was discovered by experience when processing 80 year old Pyrex tubes and that the same forces also apply to more recent, but still 60 year old glass in our 1950s color tubes does not really astonish him.

He also explained than to obtain a successful yield result, statistics on large numbers are everything. In its heyday, RACS would process up to 15-20 thousand tubes per year, not only rebuilds but brand new tubes built in sub-contract for large electronics companies such as Thomson and Philips. Obtaining a low reject rate was the result of incremental improvements working hand in hand with the raw glass suppliers, CRT screen & bulb molded assembly manufacturers + many other parts & chemical companies.

When your only working samples are each and every one a priceless vintage tube, in tiny quantities (right now 10) and that each temperature ramp up/ramp down is a feat in itself just not to rupture the bulb or crack the suspended internal phosphor screen, it's not easy.

Aside from that, RACS has now streamlined its production gear to one complete line, screen coating to finished CRT. They are in the process of renting the now freed factory space. They want to continue operating with reduced overhead costs until the end of 2013 and possibly longer.

Philippe R. gave me his word that no possibly salvageable equipment for future ETF use had been sent to the dump, so i really hope that at ETF Convention some real progress can be made as to the decision to transfer or not some of this gear & supplies to the US.

Best regards guys,

I'm trying my best, but not easy...

Jerome"

[ppppenguin]

Originally Posted by John Folsom

..... that each temperature ramp up/ramp down is a feat in itself just not to rupture the bulb or crack the suspended internal phosphor screen, it's not easy.......

At least with the EMI 6/6 CRT that I wrote about in the 1980s we had the option of not heating the whole CRT. In retrospect it was likely a wise decision to pump it cold. The early shadowmask CRTs look like a much more difficult problem. I wonder how many failures RCA had before they could reliably produce these tubes.