Need flyback for 1947 GE model 801

[Bill B.]

Hi, Guys. I have been into tube radio restoration for years, but I'm a newbie here with my first old tv to restore. My set is missing the all of the flyback assembly. The schematics call for a GE pt# RTO-032. From some pics a buddy with the same set sent me, the original flyback assembly included a pre-wired socket for the high voltage rectifier tube, which is also missing. All I have is the insulated frame the rectifier tube evidently snapped in to. Through google searches, I found several possible replacement flybacks. Could anyone please tell me whether or not the Stancor A-8130, the Thordarson Fly 3, Merit HVO-7, or RAM X045 would be the correct replacement, and if those assemblies include the rectifier tube socket?
Update 04/05/08: Thanks to Don, I found the flyback I needed. It's a Stancor A-8130 that I just need to figure out how to wire in now.
Thanks

[refill233]

I have a Stancor A-8130 and a HVO-7 and neither one has the rect. tube socket. Should be easy enough to find one to wire in.


Later,
Don

[Bill B.]

It seems that the replacements assume you have all the original parts in place, so you just replace the transformer itself? My biggest concern is to work in the anode connector that goes to the 10BP4.

[refill233]

The Ram X045 is a direct replacement for it. I don't have a sub book on the other two. Some one here can sub it for you. Great people here and they help alot. Seems like all you would need is a tube socket,tube and anode lead.The replace -ment flybacks have the filament leads on them. I'm sure you have a couple resistors that go on the bottom of the tube socket. You need a diagram of it for sure. The hv rect tube will probably be a 1B3 OR 1X2. Not sure which on that set. Hope this helps some. May have some type of doorknob capacitor off the anode wire also.

Best Of Luck,
Don

[Tubejunke]

I have an NOS Thodarson Fly-3 if one is needed. I can supply a photo for reference if it will help here.

[DaveCT]

GE confuses me. My Merit catalog shows the 801 as using three different flybacks: RTO-032, RTO-059, and RTO-071. The RTO-071 in that catalog crosses with the HVO-7. Subs are not listed for the other two. My Thordarson and Stancor catalogs show the 801 as having only the RTO-071 flyback which crosses with the Fly-3 and an A-8130, respectively.

So what gives? Did GE change part numbers on the fly (slight pun intended)?

But seriously, this is not the first time I've seen this for GE TVs.

Dave

[Eric H]

The GE service manual I have shows the 801 and the 803 using an RTO-076.

[Bill B.]

I ordered schematics from A.G. Tannenbaum. The parts list indicates RTO-032 for the flyback. Also included is an addendum referred to as "Conversion Kit, Stock RKT-001". This refers to the parts kit to be used with the RTO-071 substitute transformer in place of RTO-032 or RTO-059 in the 801 receiver. This kit includes an RLD-017 width control along with a few caps and resistors. I should have LOTS of FUN getting a replacement to work.
Bill B.

[DaveCT]

Thanks, Bill, for that information. It appears then that GE used a couple of different transformers in that model.

Good luck with the installation!

Dave

[Bill B.]

I finally got back on this project, and powered the set up. I noticed the 5U4G had some blue flashing going on, so I immediately unplugged the connector. I am pretty sure I wired the replacement flyback properly, but am unsure about manning up and letting the set stay powered to see what happens. I replaced all the caps, along with the resistors that were out of spec. Could the tube just be gassy or does this indicate a short or incorrect wiring? Any suggestions/ideas will be greatly appreciated.

[Eric H]

The 5U4 could be bad, or it might just be the surge of turning it on putting a strain on it, some 5U4's will short if laid on their side in the wrong direction.

Do you have a Variac? the best thing to do would be to bring it up slowly and see what happens, if the 5U4 gets really hot really fast then something's shorted.

An alternative to a Variac is to power it up through a light bulb, a 100 watt bulb wired is series with the set should come on bright then dim way down if everything is OK, a 200 watt bulb will probably be enough to fire the oscillators and check for HV, 300 watts should be enough to light the screen.

[Bill B.]

I did bring it up for several minutes with a 60 watt bulb in series with no indications of a problem before I threw the juice to it. I didn't see any red, but will look for it. I'll try with higher bulbs. I'll also try another 5U4. Thanks!

[Eric H]

A 60w bulb on that monster is barely enough to light the dial lights.
Seriously though I don't think it's enough to make the 5U4 conduct well enough to tell anything.

With 100 watts you can (carefully) feel the glass on the 5U4 and see how hot it's getting, if it's scalding after only a minute somethings wrong.

[Bill B.]

I brought it up with both a 100w, and then a 200w bulb, along with a different 5U4GB. The radio mode seems to be where most of the problem is. While in TV mode, the 5U4 seems fine, just getting warm after a minute. The set is pretty much dead with the 200w. I gave everything another look with nothing obviously wrong. I brought it up with a 200w bulb in radio mode, and actually tuned in a radio station at 550. After 10 minutes of listening, I brought it up in radio mode with full power. It played loud and strong for about almost 2 minutes when the 5U4 flashed blue, and I turned off. I'm going to get back into the chassis and try to locate the problem.