Sylvania 1-076 arrived! - Page 6 - Videokarma.org TV - Video

jeyurkon · #76 12-13-2009, 10:05 PM

Roger Dreyfoos suggested that the rosette was made of Repwood and not carved. After examining it closely, I'm pretty sure that's correct.

That will make it easy to reproduce and has killed my immediate desire to obtain a Carvewright. I've ordered some Equinox 35 silicone putty to take an impression and make a mold.

I've also ordered some Mohawk toning lacquer in three different shades of mahogany to try out. Hopefully one will match the existing finish.

John

jeyurkon · #77 12-17-2009, 10:29 PM

Here's a test of making a mold to copy an appliqué. I decided to try it on an appliqué on a Majestic 71 radio. It's about 1" long. The radio was refinished by the previous owner and that might account the the old finish around the piece.

I mixed up Equinox 35, which is a silicone putty and applied it. I removed it after letting it sit for the demold time of 7 minutes. I was surprised to see that no air was trapped.

I then mixed up some Bix staining putty and used that to copy the piece. The rough surface is due to micro bubbles that I didn't realize had formed when I added the water and mixed up the putty. If I use this in the future I will need to degas it. Otherwise I might use an epoxy instead.

The final photo shows the part next to the original after spraying with lacquer. The difference in color is because I only had mahogany toned lacquer when the original is walnut.

The rough surface is unacceptable so I will need to work on this some more, but the mold was easy to make and is more than satisfactory.

John

bandersen · #78 12-17-2009, 10:58 PM

Awesome! Where did you get that Equinox 35?

jeyurkon · #79 12-17-2009, 11:39 PM

I got it from TFB plastics since they're close to me.

http://www.tfbplastics.com/catalogse...inox&x=25&y=10

The manufacturer is Smooth-On http://www.smooth-on.com/Architectur...236/index.html

John

jeyurkon · #80 01-08-2010, 08:44 PM

I've been holding off replacing the 10MP4 with a 12LP4 since I was having trouble finding the right CRT socket. I collected a bunch of brighteners to steal the socket from, but they are quite identifiable as brightener sockets due to the green cap and mediocre quality. I would have had to splice the leads also which I didn't like the idea of doing.

I finally obtained a NOS EBY CRT socket. It has nice long leads and looks like it belongs. It does have an extra lead for CRTs that use electrostatic focusing. So, I have the option of cutting off the blue lead or running it down to the chassis and just not using it. For some reason, I'm inclined to do that. Some day I might find a 12VP4 and then I'd put the old socket back. And I could save the new socket in case I come across a set that needs it.

I finally had to give up on my old Pioneer RPTV. I replaced it with a 60" Mitsubishi DLP which I mounted on the wall. I now have space to put the Sylvania console under it. I'll bring the cabinet in this weekend and be able to work on it when time permits.
John

bandersen · #81 01-08-2010, 09:16 PM

I'd keep that blue lead too - never know when it might come in handy.

miniman82 · #82 01-08-2010, 10:50 PM

Quote:

Originally Posted by jeyurkon

I replaced it with a 60" Mitsubishi DLP which I mounted on the wall.

Which one? The picture quality of the 65" WD-65831 I bought last year is stellar, and I got it for a song at Best Buy.

jeyurkon · #83 01-08-2010, 11:38 PM

Quote:

Originally Posted by miniman82

Which one? The picture quality of the 65" WD-65831 I bought last year is stellar, and I got it for a song at Best Buy.

The WD-60C9. Not as high end as the 831 series, but I'm very happy with it. With it set for natural, the color is quite good. Though the blues tend to be quite electric in some scenes. I'm tempted to try the advanced set up.

I wish I knew where the vertical center of gravity is. Since I have it mounted high enough to go above the Sylvania, I'm tempted to tilt it forward by 10 degrees.

John

miniman82 · #84 01-09-2010, 04:29 PM

Whoops, just looked at the back and it's actually a WD-65735. Went to the Mitsu site, they now have 82" sets! Looks like it's trade up time, huh?

jeyurkon · #85 01-09-2010, 05:00 PM

Quote:

Originally Posted by miniman82

Whoops, just looked at the back and it's actually a WD-65735. Went to the Mitsu site, they now have 82" sets! Looks like it's trade up time, huh?

Maybe if you have a 20ft deep living room!

John

miniman82 · #86 01-10-2010, 12:04 AM

Yeah, no doubt!

Anyhow screw HD, back to watching South Park on the Philco!

Reece · #87 01-10-2010, 08:14 AM

Here's a thread where making a mold to reproduce an item like that rosette is explained.

http://www.videokarma.org/showthread...highlight=mold

Reece · #88 01-10-2010, 08:17 AM

Duplicated

jeyurkon · #89 01-11-2010, 11:55 PM

I've added a circuit to supply the screen bias needed for a 12LP4, that uses the existing 170VDC supply and a 135 V. rms tap. It comes out to 255 VDC which is really close to the 250 v typical G2 operating point of the 12LP4.

After replacing the crt connector and adding the circuit I tried operating it with the 10MP4 to make sure I didn't mess anything up. It works fine. In fact, I used to have a minor problem with a crawling horizontal and vertical distortion in the image that I had thought was from the damper tube filament transformer which is mounted near the neck of the CRT. This problem has disappeared. So has the sync buzz you get when tuning, or have text displayed on the screen. In fact the sound quality is dramatically better.

There is no reason the circuit I added should have any effect on either the sweep or the sound. Guess I shouldn't complain though.

The next step will be to try the 12LP4. I'll take photos of the circuit addition when I do the test.

I got rid of my old rear projection set and mounted a DLP on the wall leaving space under it for the Sylvania console. I've attached a photo of how it'll be set up. The cabinet is empty at this point.

John

jeyurkon · #90 01-13-2010, 09:51 PM

I've attached a photo of the booster circuit I added. It's on the board with the orange drops.

Close, but no cigar.

Yet.

I tried mounting the 12LP4. I raised the scanning bridge to the next higher set of holes which centers the yoke on a 12" CRT. However the 12LP4 is 3/4" longer than a 12VP4. The yoke has a large adjustment range to accommodate both the 10MP4 and the 12VP4, but not enough to handle the 12LP4. I was about to give up and consider staying with the 10MP4 and then having to decide whether to mount it in the 1-128 cabinet or the 1-076 cabinet. 10" would make most sense in the 1-076, but the 1-128 cabinet is the one our family kept.

But, not all is lost. It turns out that the chassis has another set of holes for a 12" CRT located 3/4" farther back that would make the 12LP4 fit perfectly. This must be the Swiss Army Knife of chassis. It was used for a large range of sets including one that used a 16LP4 CRT (at least the bridge was). The 16LP4 version has a boost circuit for the screen that uses a 6X4. There is a hole already punched for it in the bridge. I could have gone that route, but I would have had to reroute too many wires. It would have been a lot of work and the work would have been obvious. So, I used a silicon diode version of the circuit that I could hide underneath.

But, the bell of the 16LP4 is 4 inches longer than the 12LP4. I'm guessing but it seems that they had designed the chassis to be able to use the 12LP4 but never built them with it. The 12VP4 was probably less expensive, especially since they could leave out the 6X4.

When I do move the bridge back, the cross brace may not have a set of holes for it. It had one for raising the bridge, but I suspect there won't be a matching location for both raising and moving the bridge back. I may have to make a different cross brace. Not a big deal since it's just a flat strap with a bend and each end.

John