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-   -   New '60s Philco Roundie (http://www.videokarma.org/showthread.php?t=267813)

Electronic M 10-03-2016 09:20 AM

Sometimes H out tube current test points are there but not indicated on the schematic.
If not present I like to add one as well as protection by placing an above chassis fuse holder in series with the H out cathode...The right fuse will protect it, and I can pull the fuse and replace it with a current meter to check current whenever I feel like it without need to pull the chassis to check.

DaveWM 10-03-2016 09:41 AM

Quote:

Originally Posted by Hagstar (Post 3171123)
I may go with a simplified start up procedure as I strongly suspect the recycle store already powered this up, can't even be sure they used a variac.

Thanks again, will report.

Right that's a good point, its often already been started cold full power. Sometimes you will find one with a badly disintegrated plug that clearly not been used in years.

Findm-Keepm 10-03-2016 09:49 AM

Quote:

Originally Posted by DaveWM (Post 3171121)
you can get test sockets for checking HO current, plug the socket in, the tube into the socked. It has test leads coming out that you hook the meter up to.

Pomona 2712, 2712A and EBY Cath-2 (interrupts pin 2) will work.

I don't have a GC/Walsco catalog that shows the one for the 6JS6/6KD6, but they probably made one.

DaveWM 10-03-2016 09:59 AM

ok now I remember, the HV is controlled by a horz bias pot which directly bias's the Horz out. So you adj the HV to about 25kv with that pot. The regulation takes place from feedback from the fly. The problem I ran into was the excessive heat (to the point of severe wax melting and even smoke) so adj the bias down to get the heat down resulted in under scanning of the crt. That was resolved with a HV disc cap across the yoke horz windings. Pretty mickey mouse fix that maybe was not the right thing to do. Perhaps it needed a new fly.. whatever just don't leave the set alone (good idea for any 50 year old color tube set). I think I adj to about 23kv

DavGoodlin 10-03-2016 11:00 AM

Quote:

Originally Posted by DaveWM (Post 3171133)
ok now I remember, the HV is controlled by a horz bias pot which directly bias's the Horz out. So you adj the HV to about 25kv with that pot. The regulation takes place from feedback from the fly. The problem I ran into was the excessive heat (to the point of severe wax melting and even smoke) so adj the bias down to get the heat down resulted in under scanning of the crt. That was resolved with a HV disc cap across the yoke horz windings. Pretty mickey mouse fix that maybe was not the right thing to do. Perhaps it needed a new fly.. whatever just don't leave the set alone (good idea for any 50 year old color tube set). I think I adj to about 23kv

Sylvania used feedback from the fly to regulate pulse amplitude to the HOT grid on this on their later tube and hybrid chassis. Didn't Motorola do it also?

Ill make sure to copy these notes into my "Philco Color TV service manual" a Tab book by Robert L Goodman. I have a 19" chassis version of this set and its fly runs hot.

Few color TVs had a tuning meter or tuning eye tube. The OP's model might have the tuning eye tube. Only GE had a tuning device on their 1967-68 color sets and Westinghouse had that on-screen bar graphic on that one-shot chassis before they quit making Tvs. otherwise, I never saw visual tuning devices on an RCA, Zenith, Mag etc

Hagstar 10-03-2016 03:29 PM

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This little terminal board with jumper seems like it may very well be a test point. Seems I will add a fuse in place of jumper if so.

Electronic M 10-03-2016 03:33 PM

Probably is the jumper (some continuity tests/circuit tracing should tell you for sure)...The picture is blurry enough that bigfoot ought to be in it. :D

Hagstar 10-04-2016 06:30 PM

Quote:

Originally Posted by DavGoodlin (Post 3171138)
Few color TVs had a tuning meter or tuning eye tube. The OP's model might have the tuning eye tube.


I noted tonight on first fire up there is indeed an eye tube. No heating of filters, swear I hear horz sweep running yet no high voltage. The 6KD6 and most of the other tubes are Philco brand and look tired, I happen to have saved a couple NOS I came across for no other reason than they are pricey :)

The radio works, and phono cartridge but no motor action. But the whole combo looks remarkably unmolested, although as yet the TV chassis is filthy. SAMS is coming, today I got a Goodman Philco service manual from 1970.

John H.

philcophan 10-06-2016 08:56 AM

Nice find, John!!! My personal opinion, in those days, is that Philco sets produced THE most perfect flesh tones, hands down, of ANY set out there...!!! I lusted after one as a kid, but it just wasn't in the cards... one day...

Jim

DavGoodlin 10-06-2016 12:13 PM

Quote:

Originally Posted by philcophan (Post 3171265)
Nice find, John!!! My personal opinion, in those days, is that Philco sets produced THE most perfect flesh tones, hands down, of ANY set out there...!!! I lusted after one as a kid, but it just wasn't in the cards... one day...

Jim

Much of Philco advertising and shop signs had a butterfly to highlight this. Ads invite you to "take the face test" and compare fleshtones. :thmbsp:

These use some 6BL8s instead of all 6GH8s, though there is lots of both in there. The "SS" on the front refers to the tuner and IF strip only, mine had good reception before DT but it hates signal from the set-top box.

Worked on one of these wayyy back in HS VoTech and it did look good when we sent it on to a needy family IIRC. These were also loss leader sets for like $299, yes?

Can you get a neon lamp to light holding it near the 6KD6 cap? Watch for a shorted 3AW2 also, pull the cap then look for arcs. Hope its not the Fly. Think I have a leftover diagram for a replacement fly

Steve D. 10-06-2016 01:28 PM

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The Philco "Butterfly" & "Face Test" ads:

-Steve D.

Hagstar 10-06-2016 05:07 PM

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Quote:

Originally Posted by DavGoodlin (Post 3171282)
. Hope its not the Fly. Think I have a leftover diagram for a replacement fly

Why for me is it always the fly? It sure don't look healthy, and indeed reads open. Tripler time again perhaps. BUT my old pal Shango066 on youtube claims one can easily substitute another fly. 3AW2 is shattered at base, note soot.

The horz. output section seems to be intact but fly "tire" is open. But there's no horz. output voltage either so without a high voltage fuse what's also blown up I wonder?

Electronic M 10-07-2016 06:37 AM

A good place to start is by measuring base voltages on the H output tube. If the osc. is dead or malfunctioning(manifested in grid voltage), the screen bias network is damaged, or the cathode ground wire is open, then the output tube will not drive the fly properly. I'd change the HV rect and try to get the H out tube workin right. HV has a funny way of re-welding closed or bypassing small opens, and you might get lucky.
I'd be more concerned if it failed a ring test (granted you need the HV winding to ring it IIRC), or windings other than the HV were open.

DaveWM 10-07-2016 10:02 AM

Quote:

Originally Posted by Hagstar (Post 3171301)
Why for me is it always the fly? It sure don't look healthy, and indeed reads open. Tripler time again perhaps. BUT my old pal Shango066 on youtube claims one can easily substitute another fly. 3AW2 is shattered at base, note soot.

The horz. output section seems to be intact but fly "tire" is open. But there's no horz. output voltage either so without a high voltage fuse what's also blown up I wonder?

how are you checking the open on the fly? IIRC that is a little funky, like the tire HV is isolated from the rest of the windings with some high resistance power resistors. Start from the anode of the focus rectifier (pin 6 of the fly) to the plate lead for the HV tube. 540 ohms

Hagstar 10-08-2016 11:04 PM

Quote:

Originally Posted by DaveWM (Post 3171343)
Start from the anode of the focus rectifier (pin 6 of the fly) to the plate lead for the HV tube. 540 ohms

This reads a steady 109 megaohms.

John H.


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