Sylvania 1-076 arrived!

[jr_tech]

"rebuilding the two bent guns"

Wow! How does he get the old cathode out? Grind/cut away the retainer ring? Or perhaps he somehow replaces the whole cathode/grid cup assembly and re-aligns it?

Hats off to anybody that can do this.

jr

[jeyurkon]

Originally Posted by jr_tech

"rebuilding the two bent guns"

Wow! How does he get the old cathode out? Grind/cut away the retainer ring? Or perhaps he somehow replaces the whole cathode/grid cup assembly and re-aligns it?

Hats off to anybody that can do this.

jr

He has someone else do it.

When I took mine apart I gound the three spot welds. That left three small holes in G1. I don't think that would affect the operation.

I hope Bob or John correct me if I'm wrong, but for rebuilding their 15GP22 guns Bob edm's the retainer/cathode holder out. That leaves G1 intact. I think they made a tool to stamp out new retainers.

John

[jeyurkon]

I swapped the audio and HV 6Y6 tubes and the HV went from about 8.8 KV to 10.2KV. The audio has crackling noises so it's pretty clear that there is leakage in that 6Y6.

That helped the focus issue a bit. It's livable, but I think I may have a problem with supply ripple or ringing in the horizontal section. The vertical focus is quite good most everywhere now. But the horizontal is off. When I reduce the width to what it was with the 10MP4 the horizontal resolution improves. It's not just a magnification issue because the test pattern resolution improves.

Something else I meant to ask about; when I received this set the yoke was 5-10 degrees off axis. I thought it was just misadjusted, but after restoring the set that was the position it has to be in for the scan to be horizontal. It's unchanged between the 10MP4 and 12LP4.

Is it common for yokes to need to be adjusted this way? If not, what could cause it?

John

[jeyurkon]

I forgot to mention that after getting the HV back up to where it should be, the corona sound got louder and I do smell ozone. It doesn't happen with the coffee can off though. It looks like there is a discharge between the cap of the 1B3 and the can, based on burn marks on the paint. The cap seems smooth, but I guess I should try polishing it more.

About the yoke rotation, the yoke is in a steel cradle that is half a tube. A solenoidal magnet will rotate the scan. Since the focus magnet was very close to this it may have magnetized it and it could be acting like a solenoidal magnet. I'll have to try degaussing it the next time I have the CRT out.

The vertical centering magnet assembly was falling apart from age, so I made a new holder for it out of fish paper. The red paint on the ring indicates the North pole of the magnet.

The disk on the left is the original one.

John

[jeyurkon]

Since I had to move the bridge back to accommodate the 12LP4 I had to make longer brackets. The second one from the bottom is the original one. The bottom one is one that I bent from sheet stock. The third from the bottom is one that a machinist friend made. It looks the nicest, but even though it is the same thickness, it is too stiff to bend. I may have to try annealing it.

The top object is the original cross brace and the one below it is the one I made. There is very little difference between them other than the bend angle and a slightly different hole location.

John

[jeyurkon]

I also had to make a longer strap. I found a piece of strapping in a dumpster that was the right width and thickness. I cut a piece of steel for the retaining end and took a 10-32 stainless socket head cap screw, but the head off, and beat it with a hammer to make the other end. These parts are shown in the first photo. The second photo shows the original strap. The next two show the ends of the strap after spot welding the pieces on and the next two show the completed chassis after assembling the parts.

The original CRT had a brown paper strip glued around the CRT under the strap. It was also glued to the strap. I guess this was to provide some minimal protection for the CRT and keep it in place. Although not as original, I used cork. It works well and holds the CRT securely. I'll trim it up after I am satisfied with the CRT adjustments.

You can pick up a resistance welder on eBay for almost nothing. They come from China. I can't figure out if they are a knockoff of the ones that Hobart and Miller sell, or if they supply Hobart and Miller. If you do get one off of eBay, don't expect it to work out of the box. It takes some adjustments.

I also wanted to have a fire extinguisher nearby in case a spark caught something on fire. If you have a cat, don't expect the release pin to be in the extinguisher when you pick it up. I can't figure out where Schatzi has hidden it!

John

[jeyurkon]

Since I have to replace some missing pieces of the cabinet I needed to learn how to do veneer work. After doing some reading using a heat activate glue sounded like the easiest. It's safe, water based, and you can do it in your living room. You can align pieces without them sticking until you are ready.

I missed the first photo. I forgot to load the film (CF card).

I taped the veneer down to keep the glue from getting on the face. The veneer is cut larger than the plywood. I've already applied the first coat of glue to the plywood in the first photo, but I didn't apply it to the veneer yet since it's a paper backed veneer, it won't require two coats. The glue needs to dry for 20 minutes.

I was surprised at how easy this process is.

In the second photo I've applied glue to the veneer and the second coat to the plywood.

The third photo shows the veneer setting on top of the plywood ready to iron on with medium-high heat.

The last photo shows the finished product after trimming the excess veneer. At this point it would be ready to do any cutting to final size and drilling any needed holes.

It needs to sit for 24hrs before doing any finishing. I will try that next to see if I can match the existing finish.

John

[bandersen]

Very interesting - thanks for detailing your process.
How did you trim the excess veneer ?

[leadlike]

I have never really had good luck with the iron on veneer. I use very thin paper-backed veneer with contact cement. I typically reveneer an entire panel, or if it will be noticeable, redo a facing panel as well, so they will properly match. This of course involved stripping the entire cabinet. Maybe it's overkill, but by the time you are into that level of woodworking and preparation, you just may as well take it all the way.

Banderson-to trim veneer, I pretty much use whatever is sharp. I keep an Exacto knife and a variety of other razor blade tools, as well as a double edged razor blade like you find in the old safety razors-they are deadly sharp, and perfect for those tight corners. I also sand down the edges when I am done trimming. There are tools on the market that are also made for just such jobs as well, although they are really only good for straight edges.

[jeyurkon]

Banderson, I used a utility knife. I did pick up a band trimmer, but it doesn't work well across the grain. Since I'll be working with the panel later, the trimming doesn't need to be precise. But, the utility knife turned out to be surprisingly precise.

Leadike, are you talking about the iron on veneer that already has the adhesive applied or the type of product that I used? I find that this HEATLock works really well. It's thermoset so heat doesn't help if you try to remove it later.

John

[jeyurkon]

I decided to try using the method of wiping on orange shellac with a cloth to seal the wood and fill the grain. Photo one shows the materials. The shellac was cut with ethanol.

The shellac was wiped on trying to wipe most off of the surface. It was then sanded down to the surface. Several coats were applied. The result is in the second photo.

I then used Mohawk Utra Classic Toner, Brown Mahogany, aerosol lacquer to finish the board. The last photo compares the color of finished sample to the cabinet. I will be making a front panel to mount the bezel and I would like the panel to match the rest of the cabinet as closely as possible.

Being a bit red/green color blind I'm not sure how well I've done that.

I'm a bit confused about the cabinet. It's supposed to be Mahogany. The interior surfaces, even the hidden ones, are definately a Mahogany veneer that looks like modern Mahogany. The sides of the cabinet match that. The inside surfaces of the doors match it also. However, the front of the doors appear to be almost a different wood. I'd suspect that they put the wrong side out, but all of the other panels that are veneered have mahogany on both sides.

John

[bandersen]

Nice job - that's a really good color match. Maybe just a tad more brown and less red, but I wouldn't worry about it especially if it's on a separate panel.

I've used Behlen water-base grain filler a few times. It's messy and there's a lot of rubbing and sanding, but the results are excellent - a glass-like surface.

How did the shellac work out as grain filler ? I've been meaning to try it out for a while since it seems less messy.

Maybe that odd veneer is from a different batch - or maybe it is a different species. That's one advantage of toner lacquer - it's easy to mix species and get the same color.

[jeyurkon]

Originally Posted by bandersen

...
How did the shellac work out as grain filler ? I've been meaning to try it out for a while since it seems less messy.

It takes more coats than I'd prefer. I had cut mine pretty thin for another project. It dries fast though. If you're refinishing a project the shellac is supposed to stick to almost anything, even urethane. I've not tried that.

John

[jeyurkon]

Has anyone had experience with J&J tubes? I noticed that the horizontal on my Sylvania was starting to drift out of alignment so I decided to check the tubes in that section. When I plugged the JJ ECC-82 into my tube tester one set of filaments lit up like a light bulb briefly. The other side was fine. I thought I made a mistake in the settings, but I doubled checked and also checked the voltage at the socket and everything was fine. It would also make sense that the problem I was having was due to this tube.

http://www.jj-electronic.com/pdf/ECC%2082.pdf They're made in the Slovak Republic.

They look really well made, but I'm leary of getting more as replacements.

John

[bandersen]

That's just a 12AU7 isn't it ? I can send you a few if you need some.