Read Gilbert's initial CT-100 acquisition report on the Tidbits II page [titled "Sooner or Later..."]. -- Pete
8-7-01 I am seeking a channel number indicator dial for this set, which is the only part that is missing. I read where you were seeking one some time ago. Did you ever locate one? Would appreciate your keeping an eye open for one of these or a source for it.
8-20-01 I have a few more things to share with regards to my CT-100. I removed the chassis from the cabinet and vacuumed the interior of the cabinet. I hit the chassis with compressed air and blew away years of dust. The chassis is in very good condition. No signs of any radical tampering or repairs in its past.
Both fuses by the selenium rectifiers had been replaced in the past as they were clipped on with those little "S" type holders that clip on to the old fuse. Bottom of chassis is very clean, no signs of anything leaking or oozing in the past. HV compartment very clean. Looks promising.
I made contact with Steve McVoy. He asked me about the condition of the CRT and recommended that I check the getters to see if they were silver or corroded white. I moved the purity coil back and saw that the getters are a nice and shiny silver color. Another good sign, but this too is not a guarantee that the CRT will live again, but it is a positive sign anyway. I will send you a picture of the set very soon.
9-11-01 On August 23rd, my good friend Scott Rice came over for the purpose of doing some cleaning and polishing on the CT-100 cabinet. Scott had a part in my getting this set, and has taken an interest in helping me to get it cleaned up and looking nice. He is very good at doing woodwork and very enthusiastic about working on such a historic set, and so we proceeded to make the CT-100 shine again.
The finish is not bad overall. The top of the cabinet exhibits some drying out of the finish, probably due to years of warmth from the heat generated by the tubes and the chassis. The two front corners of the top have had the veneer chipped off. It is repairable, but we will consider that at a later time. Looks like at one time, the set was placed on its left side and either moved or dragged a bit, as there are some scratches on the top front and rear left corners. We were able to conceal the scratches, but upon close scrutiny, it is evident that the top layer of varnish is scratched. Not evident from a distance, but only if you look at it very closely.
We removed the knobs and the pencil box and cleaned the front panel of the set. The pencil box was also cleaned and polished up. The knobs were removed and were to be soaked overnight in order to clean them up and remove all the dirt and grime they had accumulated.
By the time we were done that night, the set looked a hundred times better than it had previously. We still need to repair the speaker grill as one of the bars is broken, and we need to address the problem of the chipped top cover. Also we need to figure out what to do about the safety glass as a piece of the inner black gasket has drooped down and is objectionable. That will come later.
On a very happy note, Steve was kind enough to offer me a channel indicator knob, which as you will recall, the set was missing. Steve indicated that the brass colored insert was missing on this piece, but that I might be able to paint it in or otherwise make do. I took Steve up on his generosity, and several days later I received the knob in the mail. I was very happy to get it since I thought perhaps I might have a very difficult time locating one.
As I examined the knob arrangement, (actually composed of three pieces, a wine-colored back piece, the thin paper disk which has the channel numbers printed upon it, and the front clear plastic piece that attaches onto the tuning shaft) I got the feeling that I had seen the clear plastic piece before...Maybe in my own parts collection?! I went rummaging and I found I had a NOS clear plastic piece with the medallion. What a find! Now I could use my piece along with Steve's paper disk and back piece and get a new-looking knob. That's exactly what I did and now I am happy to report I have a great looking channel number insert knob.
I might make a quick comment about the medallion. I call it the "airplane" since to me it seems to be some form of stylized plane or rocket that seems to be taking off or flying about. The two shapes within the medallion are a semi-circle and one that looks like a wedge but to me resembles an airplane. I am wondering if this same medallion was used on the entire run of CT-100s? It sure dresses up the set to have this knob in place and it is refreshing to have guys like you, Pete, and Steve in this hobby. More to come soon.
10-21-01 On August 30th Scott returned once again to help me with more cosmetic work on the CT-100. The first thing we did was to remove the speaker board for the purpose of repairing a break in the left-hand upper grill bar. Each screw was removed and the board loosened and taken out with the speaker still attached and the outer side covered in grill cloth. Beware when loosening the last screw...The board will fall out of position instantly. Have a hand or two ready to catch it.
With the board out of the way Scott proceeded to mend the broken pieces by using Elmer's dark wood glue and a few clamps and pieces of scrap wood. A trick here in gluing the narrow bars is to try to clamp them so they are under pressure both in a horizontal and vertical plane, since the wood does not have a great deal of surface area to hold. While Scott worked on this I took the speaker board outside and dusted it off. The speaker itself had much dust as you could imagine. The other thing I did was to brush off the grill cloth. Although the cloth looks good when it is mounted in the set, outside a very clear comparison could be made to the original color in areas hidden by the edges of the grill and the exposed area, which as you would expect was faded. I took a paintbrush and dusted the grill cloth in an attempt to remove all loose dust. Since this cloth has no rips or snags and only exhibits some fading and minor discoloration, I decided not to attempt any radical or potentially dangerous cleaning operations on it. As I said earlier, the cloth looks good once it is placed back
We will leave the speaker board off for now as the grill bar is clamped and drying and once all of that is done, some more cleaning and polishing will be done in that area.
Next we set upon the removal of the safety glass to address the problem of the gasket material which has drooped down from the top of the glass as well as some more cleaning. The glass is held in place by the metal bezel that surrounds it. The bezel is held in place by 8 clips which are the same type that RCA used in their later sets to help hold back covers in place. Remove all of these clips which are located on the edge of the mask all around the CRT. One of the bottom ones has a grounding wire attached to it. When they have all been removed, the bezel is removed as one unit, although it can be removed in pieces but I recommend you pull it gently out and carry it away as one unit. At this point we thought "the safety glass will just tilt right out"... WRONG! The gasket material also serves as a mastic type substance to hold the glass in place. We tapped around trying to figure out how to get the glass off without destroying anything. Finally we decided that the best way to do this would be to ever so gently pry the glass off somehow. We got a wide spatula, and I had the idea to bring out an old hair dryer on the assumption that perhaps warmth might soften the old gasket and allow the glass to give way.
If handling the CRT is a harrowing experience, then handling and trying to remove the safety glass from a 47-year grip has to be the next most harrowing experience. As Scott gently pried on the edges, I followed along with the hair dryer trying to coax the glass off of its perch. For several minutes the attempt seemed futile. We could not get any edges of the glass to release its bond. After pausing for a minute or so we tried again and this time Scott found a sweet spot. I didn't even notice it to be honest but he said he had broken the seal on one corner. Scott said if we could just keep the glass moving away from this point, the grip would be broken. Remember, this was just one corner and the rest of the glass was still holding on. By gently applying pressure and keeping some light heat on the corner, we got the glass to give up its grip and it came loose in Scott's hands. Whew, what a relief to have it loosened and now resting on a thick blanket on the top of the set.
The first thing I did was to attempt to clean some staining from the CRT mask which happened when that piece of gasket slipped down a period of time. I tried using an old cotton sock and a bit of Windex to remove the black staining from the gasket. Windex is notorious for dissolving station numbers on old radio dials and for discoloring certain materials. Since the edge of the mask is a nice shade of red, I gently tried to wipe a corner of the mask area and check for colorfastness. Only a slight bit of red wound up on the sock after gentle pressure. I found that by carefully rubbing not too hard, Windex will remove the left over gasket material and will not harm the mask. If anybody tries this on his or her own, let them beware and try their own tests.
I was able to clean the mask and with a razor blade remove the piece of gasket off the safety glass that had fallen. At this point, I felt it would be best to stop and give some serious thought to either renewing the gasket or coloring it to fill in the gaps and faded areas. I didn't want to rush this step so I stopped and decided to just take my time and think about it. At this point we concluded our tasks for this day and ended this next step of restoration.
1-5-02 About a week or so passed by and the horizontal bar of the CT-100's grill remained clamped. The Safety glass was off as was the bezel, which surrounds the glass. I gave a lot of thought as to how to freshen up the gasket material around the glass.
Several possibilities came to mind. One would be to completely scrape off the old gasket and search for a suitable replacement gasket with similar width and thickness. Another possibility is again scraping off the old gasket and just painting around the perimeter of the glass with black paint. I always like to save or repair things whenever possible, rather than replace. I have done this with old radios before. So keeping this in mind, after a lot of thought, and the fact that about 80 percent of the gasket was fine, I decided to leave the old gasket in place, but mask off the edges and freshen up the gasket area with a couple of coats of gloss black paint.
What I did was to carefully scrape off any loose areas of gasket material with a razor blade. Next I cleaned the edges of the glass next to the gasket material. I got some masking tape and masked near the edges of the glass leaving the gasket area exposed. I did not agonize very much over making exact measurements, and being super-precise. I relied on my sight and placed the tape carefully so that it butted up against the line where the gasket is (or was). I did this all the way around.
Scott dropped by and we got a can of gloss black paint and with a small brush, painted around the edge of the glass going over the area where the gasket still was and equally over the area where it was gone. We set it up and let it dry overnight. The following evening, I repeated the process giving it a second coat.
Since the paint is not thin, it helped to fill in some of the uneven areas. The following evening, I gave it a third coat for good measure. Now I would let it set up for a few days and let it dry completely. After several days, I gently peeled off the tape and the results were rewarding. The trick here is to let this set for several days to allow a thorough drying. The day after I removed the tape, I put the glass plate outside for an hour or so allowing the warm sun to "bake" the paint on. I feel that for me, this operation was successful and saved me from having to search for a suitable replacement gasket. The final step in this is to once again take the razor blade and gently smooth out any areas that might be uneven along the edge of the paint.
Getting back to the speaker grill, we removed the clamps that held it together and found the joint thoroughly dry and strong. There was still a visible crack due to slight splintering and the impossibility of doing a seamless repair on this part. We went about cleaning and polishing this area and after that had been completed, the crack areas were treated with some stain that was the same Mahogany color as the cabinet. One part of the crack completely disappeared! The wider part was camouflaged and only on very close inspection is it visible. After being satisfied that the grill area was repaired, cleaned up, and polished satisfactorily, the speaker board was reinstalled by replacing all of the screws from the inside bottom of the cabinet.
Next the safety glass was reinstalled. It was seated back on its ledge, and the bezel was reinstalled. The retaining clips were carefully replaced from the area inside the cabinet around the CRT. The bezel was checked for alignment and found to be satisfactory. As with removal, having a friend to lend a hand makes this much easier.
Taking a step back to view the set with its clean safety glass and repaired grill made us feel great. The prior polishing work we had done made the set shine. Both Scott and I stood back and admired the CT-100. It really is an attractive receiver.
I might mention that the paint job done around the perimeter of the safety glass wasn't really visible once the bezel was in place around the glass. I feel however, that because of the several coats of paint that were applied to the perimeter, they will help in keeping dust out off the face of the CRT. I still feel better about doing it this way than having to strip off all of the gasket material and trying to find a suitable replacement.
9-2-02 I decided that I would try to apply power to the CRT and see once and for all if the filament would light.
I was considering connecting a filament transformer to the heater pins of the CRT and then plugging in the transformer to a variac and hanging a meter on the filament leads to monitor voltage and then slowly crank up the voltage and apply, say three or four volts to the CRT and observe what happens. This is exactly what I did.
Steve McVoy had suggested simply connecting 6 volts to the filament pins because, as he rightly stated, either the filament will light and hold, or it will burn out if the vacuum is gone. I decided that I would first bring the heaters just to the glow point.
Again Scott was present, and I made all of the connections and double-checked everything. I applied power to the variac and very slowly cranked up the voltage while observing the VOM connected to the filament leads. I raised the voltage and watched the neck of the CRT for a dull orange glow. For the first couple of volts nothing happened. Then, after applying about 3.5 volts, I noticed a dim glow coming from the filaments! They were lit once again after many years. It was like two kids watching lights come on a new Christmas tree.
We left the filaments on for about five minutes or so, and then I cranked the voltage back down and disconnected everything since the main objective of this test was to see if the fils would light. At a later date, I will apply 6.3 volts to the filaments and let them run for much longer.
I have read where applying three or four volts or so to the CRT for a long while might be beneficial in burning off gases and stabilizing the gun assembly after so many years of sitting idle. Will have to do more research into this. But for now I was happy to see the filaments glow, at least dimly, and for a few minutes, but glow nonetheless.
4-27-04 Back in October I connected a CRT checker to the 15GP and it told me the emission is in great condition on all three guns! Definately good news. I am hoping to get back to it and start writing some more for the info exchange page.
9-17-08 I'm writing to let you know I have discovered and acquired another CT-100.
I got a call from a friend about a week ago telling me he had been in contact with an old guy who had a bunch of electronic gear to get rid of including several old TVs and "a 15 inch round-tube color TV set." I called the man up and spoke with him, and he said that he had such a set and that he wanted to get rid of it for nothing, just haul it away. He said that it was not an RCA, but it had an RCA chassis. I thought about this and wondered what it could be. One of my thoughts was that it might be a CT-100 but he had his facts mixed up. On the other hand, I thought maybe it is something really exotic. I made arrangements to meet him.
The place was so far out of San Diego the last several miles of road were unpaved, but finally I arrived at his location -- property he owns out in the desert. He had two old, large truck bodies like cargo vans. It was obvious they had been out there for quite sometime. After fumbling around trying to find the right key to open the cab, he raised the door, and there before me was a CT-100.
I asked him how long this set and all the other stuff he had had been in there, and he said "about 40 years!" I don't know if it had been that long, but it was evident that being in that van for a long time had taken a toll on the set. The finish is flaking off and the chassis exhibits a good deal of corrosion. It looks complete except the HV cage is missing and the channel indicator and medallion knobs are gone. Looks like some parts have been changed out over the years. He added, “The man I got it from was into TV servicing as a hobby and he told me that he had worked on that set before.”
I can only imagine the temperature extremes this poor set went through in that van. To give you an idea, I also took a 7-in. Motorola that was in the same van, and the rubber gasket that surrounds the CRT had melted, yes melted and had run over the face of the CRT! Probably scorching in the summer and freezing in the winter.
I loaded the CT-100 into my truck along with some more goodies and made the trek back home. I thought the CRT was probably shot being subjected to those extremes of temperature. That night, I tested the CRT and to my great surprise, the filaments lit. Everything looked promising until I pushed the "emission" button, and then I got the blue glow of death around the gun under test. Shat! I knew that CRT was going to have troubles. Still, the glow was not gigantic, and the emission on the guns was decent, except for a weak blue gun.
The vital stats are as follows: Chassis serial number is B8001132. Cabinet 227. Front wood insert 227. Lid 210.
I can't believe that I have been fortunate to acquire two CT-100s and they were both free! Maybe I should buy a lottery ticket…!