GE 810 restoration

[kbmuri]

Awesome!

The Sams sheet appears to have left out mention of these two trimmer caps in the Parts List (should have been under "Controls", or at least under "Capacitors"). Also, on the set, they're only labeled on the cardboard back (not on the chassis). My (2nd) set is missing the back.

Thanks for pointing them out.

[bandersen]

I decided the original grill cloth is just too ratty and ordered up a square yard of this stuff. The weave is somewhat different, but the color is a good match.

[kbmuri]

Bob, one small nitpick.

The cardboard back has a round opening for the socket of the picture tube to protrude a little bit. There's no cap on it, by the way. The round hole has a quadrant from 3-o'clock to 6-o'clock that's larger diameter. The purpose of this extra width is to allow the socket wires some room to breathe & less likely to be pinched against the neck. Perhaps also to let a repairman remove the socket and test the CRT without removing the back (?). Anyway, the CRT should be oriented so that the socket wires are at 3-6'oclock so that they'll be visible and accessible with the back installed. You have yours at 6-9'o'clock. You should rotate the CRT about 90 degrees left (viewing from rear). You probably have the anode cap straight up (?). Should be straight left instead, nearest the HV cage.

Unless your tube is a rebuild. I wonder if they made an effort to fuse the new gun onto the old bell with a precise angular orientation...question for the masters out there, I certainly don't know.

Anyway I know I'm picking nits. Excellent restoration to this point.

[bandersen]

Like this ?


Unfortunately, if I do that the CRT anode is way down near the chassis I don't think my CRT is a rebuild, but I haven't looked that closely.
I suppose it would work, but I don't like having the HV that near the grounded chassis.

[Reece]

If that's the orientation it has to be, you could glue some plastic onto the chassis at that point for extra insulation.

That grille cloth is similar to that on some radios I will need to work on. Mind telling what was the source? Thanks.

[marty59]

Quote: "Unless your tube is a rebuild. I wonder if they made an effort to fuse the new gun onto the old bell with a precise angular orientation...question for the masters out there, I certainly don't know."

I have an NOS 10SP4 (electrostatic focus/aluminized and tinted face) tube that is practically useless as it was meant for some kind of monitor application. However, before Scotty shut down I sent it to him to replace the gun with an electromagnetic type to I can use it in place of a 10BP4 or as a 10FP4 which it (electronically speaking) now resembles. Scotty did orientate the gun as it was placed originally as in the 10SP4, as he made the point to install the guns as they were installed as a rule.

[bandersen]

Originally Posted by Reece

If that's the orientation it has to be, you could glue some plastic onto the chassis at that point for extra insulation.

That grille cloth is similar to that on some radios I will need to work on. Mind telling what was the source? Thanks.

Yes, I suppose I could. First though I think I'll check my GE 806. I think it has a 10FP4 and it might have a base in the proper orientation.

I got the cloth from Discount Guitar Output: http://stores.ebay.com/Discount-Guitar-Outlet

[kbmuri]

Inventorying my loose round B/W tubes, it would seem that (looking from back) the convention was to position the anode at 9-o'clock, and the center pin of the 5-pin group (pin 12) at 6-o'clock. The overriding majority of my stuff is like this, and I assume it's the norm. Your tube is correct and I guess the wires won't go where I thought they should.

I have 3 tubes that do not follow the convention (with anode at 9:00, they are at 7:30, 3:00. and in one of my GE810's, at 4:30). The two tubes at 7:30 and 3:00 are rebuilds (seam on neck). So at least some of the tube rebuilders out there were not as diligent as was Scotty. No plans to remove CRT from the 4:30 tube to check, but I'll assume it's a rebuild too.

I didn't pull my pristine 810 very far away from the wall and checked behind with a flashlight (as you can tell from the post it was 2am). I must have had my left and right reversed, I checked for the wires and hole clearance, and then wrote my report. But as it turns out on closer inspection someone carved the slot larger to clear the wires, in the 6-9 quadrant, sometime in its ancient history. It looks like the tube in it is normal too.

So I retract my suggestion, lesson learned.

[kbmuri]

Sams (53-12) is somewhat inconclusive, but studying page 3 and page 11 it seems like the intent was to orient the wires over the wider opening. I seem to see a wire at 3:00 on page 11 and the cable as a whole clearly exiting bottom right, on page 3. Maybe they did put the anode that low (?). It's a mystery.

[bandersen]

Here's what Beitman's Most-Often-Needed had to say about it.
They show the anode inline with the base key. Seems there must have been some CRTs made with this orientation. None I've checked so far do.
I have a NOS GE 10FP4 that I'll dig out and check.

[Tom Albrecht]

My GE 810 has a GE 10FP4A in it, and with the anode connection in the right place (straight sideways), the socket key points to approximately 6:30 or 7:00 when viewed from the rear. This seems very similar to what banderson is seeing on his.

Tom

[kbmuri]

Originally Posted by bandersen

Here's what Beitman's Most-Often-Needed had to say about it.

Well, that would put the wires in the "right" place. I would imagine if GE made the TV and GE made the tube, GE could orient a CRT run to optimize their needs.

I would also imagine that the "normal" orientation probably became the standard, de facto, sometime later than 1949, even for GE. At least for replacement tubes.

The working 810 I've been showing you has an RCA Victor 10BP4 and an ion trap magnet (its original 10FP4 is in the ETF museum's color wheel display). The RCA's keyway is "normal" at 6:30 when the anode is at 9:00. The mint 810, I'll look at more closely when I get home. I have 3 other "parts" 810s, one doesn't have a crt, one has an RCA Victor 10FP4, and the last one has a GE 10FP4. The RCA 10FP4 seemed to be rotated almost correctly but I didn't look for the anode cap in it. These parts sets are buried behind stuff down in the mancave and hard to dig out. I just shined a flashlight at them from a distance the other latenight to get this info.

Glad Beitman's clarifies. Would be fun to find one with the key oriented that way. I guess if I wanted to get really anal, I could make one by insulating the tube wires, lengthening them, and rotating just the cap...

[jeyurkon]

Just to add another data point I took a look at the 10FP4 I recently picked up. The anode connector is in-line with pin 2.

John

[bandersen]

Thanks for checking guys.

I checked my NOS GE 10FP4 and two other 10BP4s all have the keyway at about 6:30 when the anode is at 9:00 as well. About 40 degrees apart in other words.

I think I'll just stick with the CRT that's in it now. For all I know the CRT in mine is the original one it shipped with. If you check back to the first page of this thread, you can see the anode is out the the left and the back cover fits on OK around the CRT socket.

[kbmuri]

That's a good way to put it. The tubes I've been calling "normal" have the anode connector in-line with pin 3.

My RCA 10FP4 is inline with pin 3, as are my loose 10BP4s and 12LP4's and etc.

Looks like the Beitman's diagram wants one that's inline with pin 6.

I have a Farnsworth 160 that's inline with pin 6, but it's a rebuild. So no conclusions there.

My GE 10FP4 is in line with pin 2. Definitely 30 degrees off "normal", but still not at pin 6. Don't know if it's a rebuild. It's in this set:

Which I'll work on someday if I find (another) set of knobs.

This cabinet:

has an equally dirty chassis somewhere. Not in the mancave, out in the garage. I kept the CRT inside, a GE 10FP4, but it glows pink from air in the tube. Will have it rebuilt someday, if ETF rebuilding happens. Anyway it's a pin 3, like normal, and not rebuilt. So GE made at least one "normal" variety 10FP4.

So not much learned. Am convinced that a truly concours restoration would need a pin-6 orientation. But like I said awhile back, it's a huge nit.

Oh, I see Bob just posted before me, and he agrees. Use the tube as-is and let the wires fall where they may...