10-1-2000 This new restoration log page is timed to coincide with an autumn thrust to rebuild our vintage tricolor cathode ray tubes and continue the drive toward functional vintage color television.
At long last, an engineering drawing for a stem used to rebuild the 15GP22 and 15HP22 tricolor picture tubes has been located, and a copy was acquired by Bruce and forwarded to this site on September 28, 2000. Somehow it doesn't look that impressive, but it represents hours searching for a manufacturer with the wherewithal to provide this element in the complete process.
As has been pointed out by collectors, the 15GP22 evacuation stem is copper and can be seen through an access port in the base. Our evacuation stem, all glass, is 0.5-in. diameter and may be reduced to 3/8-in. While still under investigation, it is possible that the copper stem played a pivotal role in the removal of gas ions during the final evacuation process. If this is the case, the four unused leads, earlier thought to be unnecessary, may serve as a surrogate for the copper stem.
It's a good bet that RCA in 1954 never recovered a penny of its CT-100 production costs. So let's not overlook weighing the practicality of this venture fifty years later. Our ultimate success is predicated upon affordability. The services of no less than three separate companies across the United States are involved. Economies of mass production don't apply. There are start-up costs. There are economy-of-scale issues: the cost of one critical procedure may be the same whether one or four tubes are processed at the same time. But the glass is half full, not half empty. The very fact that these things are being considered now attests to the advanced state of the project. And the heartening thing is -- the pathway looks bright.
4-12-2001 It's been six months since rebuild information has been added to this page. What breaks the ice is a plan now being finalized that will test the efficacy of a 15GP22 rebuild process. Plus, Bruce resolved a critical requirement; a quote to manufacture stems (see drawing above) for 15GP22 guns is in hand.
We have one stem that was made years ago. We have an electron gun assembly that was rebuilt years ago, then matched to a stem from a 21AXP22, and sealed in an airtight container. The plan is to recover the 15GP22 gun from the 21AXP22 stem, mate our 15GP22 stem to the gun, and have in-hand the first such assembly to be produced in perhaps thirty-five years. Bruce is now selecting a dud 15GP22 (from more than thirty in our queue) that is most likely to be successfully rebuilt. His strategy is to rebuild a tube that has never lost vacuum -- one that still has silver getter flashes. If it works, the more complicated task of rebuilding a gassy leaky tube will be tackled.
My dreams of watching the 2002 Rose Bowl parade on my CT-100 are getting better all the time! --Pete
7-30-2001 Actually did some cosmetic work on my CT-100 (chassis s/n B8000173; cabinet s/n 605) yesterday -- picked up an 8-inch wide-range speaker for $20 at Radio Shack and installed it using the original hardware. The factory-installed speaker had been damaged before I bought the set in 1963, and so I had jury-rigged a 6-inch replacement, which also was lost sometime over the decades of storage. Also used a soft toothbrush, detergent, and water on the front knobs I still have: volume control, brightness, fine tuning, and channel selector. I am missing the channel indicator insert and so must find a replacement. Incidentally, Radio Shack had two 8-inch speakers to choose from, both cost the same, but one was an acoustic suspension design and the other was not. Since I have no interest in modifying my Merrill by building a fiberglass-filled air-tight enclosure inside the speaker baffle/chamber, the standard speaker was the one to choose. It had a 10-watt rating versus 15 for the acoustic suspension design, so it was even better suited to be driven by the 2 to 3 watts from the 6AQ5 class-A audio amp.
4-16-2003 A picture is worth a thousand words...
5-30-2005 In the two years since the last entry, numerous advances and failures have taken place in an attempt to restore a 15GP22 to operation. Today, Memorial Day 2005, we await word on yet another attempt to bond a stem to a 15GP22 dud and then evacuate the beast. This time, it may work. If not, the small group of vintage color television caretakers who give of their time, talent, and funds in this noble effort, will try again.
On a second front, I was asked recently at the 2005 Early Television Convention when I would finish the restoration of my CT-100. Essentially arrested when it became clear in 1999 that my 15GP22 had gone to air, the years that passed were applied less to restoration and more to developing this site and forming friendships and dialogs with those who share the 'Merrill fever.'
My CTC2 chassis, B8000173, which has been with me for over four decades was declared a donor chassis in April of this year. Already, parts from the chassis have literally been spread from one coast to the other.
As to my restoration effort, I was fortunate to have acquired a second Merrill in August 2004 after nearly a year of negotiations. This CT-100 is a brother to my original Merrill. With chassis number B8000194, it was rolling down the Bloomington assembly line within hours of old '173. They are both early production units. They are both virtually identical in terms of production procedures.
It is with this CTC2 chassis that I continue the restoration process.
Ninety dollars worth of modern capacitors and four weeks of work later, B8000194 lives again. For the first time, ostensibly since 1956, the chassis regained life once more on May 29, 2005 with sound and
Furthermore, I have been fortunate to have available to me a late production Merrill from the end of the CT-100 production run. In pristine condition, this Merrill was bought by a consumer, almost never used, never repaired, and was stored in a controlled environment favorable to preservation. By comparing one against the other, already hitherto
in the production run have come to light. Additional restoration information is forthcoming in a new Restoration Log.