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  #61  
Old 12-31-2016, 12:59 PM
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Electrolytics are all OEM in this set, no heat or current excess but I will now replace them.
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  #62  
Old 12-31-2016, 04:43 PM
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Look at tube heaters as it does it's warmup cycle. I had a RCA set that lost green during warmup and intermittently with long cycle time. It was a bad socket...Also reflow solder on ground stakes on the PCBs...They get flaky and are heater and signal/B+ ground so if one or more open even temporarily they can cause REAL odd problems
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  #63  
Old 02-18-2017, 09:16 PM
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Well after months of head scratching and breaks for other projects I finally solved the slow start and AGC issues. I did a full 'lytic recap but I think the starting issue was a cold solder joint or two, fixed a few. After checking everything else replacing the pulse gate transistor brought back AGC voltage even though it seemed to test fine in place (this set is solid state front end, color and sweep all tubes). An NTE123A as OEM however did not last long in circuit- this transistor is where the hybrid part happens- the noise inverter tube provides a static 160 volts across the transistor with 35 volt peak sync pulses so it has a hard life. I swapped it out for a video driver NTE 128 transistor and voila, almost normal picture and proper AGC action.

Last edited by Hagstar; 02-19-2017 at 07:34 AM.
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  #64  
Old 02-19-2017, 12:29 AM
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Just found this Philco roundie ad from Aug. 1967. Promoting it's under $300.00
color TV.
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  #65  
Old 02-21-2017, 10:11 PM
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Built December 5, 1966

Success! The Philco stereo phono/AM/FM receiver section is in and sounds great relatively speaking of course. Also last week I managed with the invaluable help of Chris Cuff's videos to clean and tune up the Philco badged Voice of Music record changer model 100C. The receiver's volume issues turned out to be simply dirty pots. I remembered low voltage modern circuits are like that. Either adding metal cabinet extension speakers (it has RCA jacks for them) or adding better speakers would be good as the 4 GE2 transistors manage to overwhelm the speakers which appear to be 2 oz magnet single 8" cone. The TV just uses the usual little speaker and can't play thru the hifi, could be arranged with some sort of switch box.

I had to repaint the top of the main tuning cap housing due to rust but otherwise I just cleaned it with brake cleaner, DeOxit for the pots, bits of lube for pot shafts and dial drive. Oh and a resistor and LED tuning light was added to replace dead OEM bulb (lower left).

December 5, 1966 (Monday)
In a case frequently cited as an example of the phenomenon of spontaneous human combustion, Dr. John I. Bentley, a 92-year old retired physician and surgeon, was found dead in his home in Coudersport, Pennsylvania. An Associated Press report noted only that he was "found dead in his Potter County home Monday, apparently the victim of a fire" and that "His clothes and the floor were partially burned." [17] The facts were more gruesome, because a meter reader found only a pile of ashes, and that the only identifiable portion of him was "his lower right leg, still clad in its bedroom slipper, and his walker, which strangely enough suffered little damage", as seen in a famous photograph of the death scene.[18] Some authors have blamed spontaneous combustion [19] Other authors point out that the leg as "lying at the edge of a hole about two and a half by four feet that had burned into the basement" and that Dr. Bentley was a pipe smoker who had previously been burned from dropping matches, or hot ashes, onto his clothes. A plausible theory was that Bentley had accidentally ignited his robe, attempted to douse the flames with water from a pitcher, ignited the linoleum floor the hardwood flooring and wooden beams beneath it.[20]
The United States Supreme Court ruled unanimously that Julian Bond had been improperly denied a seat in the Georgia House of Representatives after winning two elections to the state legislature. The Court concluded that the basis for the disqualification Bond's criticism of American policies in the Vietnam War) had been a violation of Bond's right to free speech. "Legislators have an obligation to take positions on controversial political questions," Chief Justice Earl Warren wrote, "so that their constituents can be fully informed by them," and added that the denial of the seat "violated Bond's right of free expression under the First Amendment".[21] The House would, reluctantly, administer the oath of office to Representative Bond, along with all the other members, on January 9, 1967.[22]
The successful musical I Do! I Do! opened on Broadway, at the 46th Street Theatre, and would run for 560 performances. The entire cast was limited to two actors, and only one set, as the play followed the course of a 50-year marriage. Mary Martin and Robert Preston were the first to perform the roles of Agnes and Michael Snow.[23]
Buffalo Springfield's self-titled debut album was released.
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Last edited by Hagstar; 02-22-2017 at 09:42 AM.
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  #66  
Old 02-22-2017, 08:04 AM
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Ah yes, last of the US-built solid state radio chassis. Philco would later shift this work to Taiwan, still a decent product but not so easy to work on. Nice work.
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  #67  
Old 02-22-2017, 01:13 PM
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I noted in my Philco manual that later hybrids used a low voltage not high voltage transistorized TV AGC system- I bet they had plenty of trouble with the pulse gate transistor.


Still odd the used video output tube works but a new one creates only a very dark picture. This chassis controls brightness via the video amp.
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  #68  
Old 02-24-2017, 12:06 PM
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Here's a few shots of my '67 Philco Roundie, that I bought from the original owner. He bought it new and put it into service in November, 1967. He had a custom laminated glass cut and edges polished, for the top of the set, to protect it's finish! The way I have it displayed, is the way I found it, with a "condensed operating instruction sheet" under the right-front corner of the glass, with a note written on it in his pen. This TV was still connected directly to an outdoor antenna (no D/A converter box at all), so it must have had occasional use up until the 2009 changeover, as we have no analog stations on UHF, or VHF whatsoever, here. Every tube in this set was the original, I had to replace, IIRC, 3 color circuit tubes, I believe all three were 6GH8A's (no surprise. New 3.58 crystal, new Vert. HT. pot, to replace the broken one that he likely tried to adjust, at some point, with the wrong tool! CRT is original 21FJP22A Philco, and I had to perform a mild gun-cleaning restoration, it's cataracted and somewhat "tired" but will do for now.
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File Type: jpg Rear Cover Label.jpg (82.4 KB, 15 views)
File Type: jpg Chassis View.jpg (92.7 KB, 25 views)
File Type: jpg Sample Pic_3.jpg (70.7 KB, 32 views)
File Type: jpg Sample Pic_4.jpg (68.4 KB, 35 views)
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  #69  
Old 02-24-2017, 05:25 PM
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I do have a vexing issue still with the AGC that I don't understand. Originally I had no AGC voltage at all. After changing the two AGC diodes and both gate and amp transistors I do have voltage of 3-6 volts depending on AGC control setting. BUT there's an 8 volt zener that spills voltage into the tuner AGC line and I never get voltage that high. A high signal input from the test equip. increases voltage from 5.5 to 6 volts, that's it. BUT the schematic calls for around 5.5 normal with signal so I'm not sure what's right. The service manual for similar models says I should be able to get 2-14 volts....

Pulses controlling the AGC gate from the coil on the new flyback are weak on the positive side through the diode but strong on the negative side....
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Last edited by Hagstar; 02-24-2017 at 07:49 PM.
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  #70  
Old 02-24-2017, 06:20 PM
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It's hard to read the schematic well enough to tell, but two thoughts come to mind: 1.) the zener may be meant to keep the tuner signal under 8 volts in the event of AGC failure to protect the tuner. 2.) they are using the fixed voltage drop off the zener to increase the DC voltage level going to the tuner relative to the IF AGC bus.

Once you start looking at SS gear schematics you start to find all sorts of clever ways to take advantage of the new properties of SS devices.
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  #71  
Old 02-24-2017, 08:03 PM
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No the zener serves a delay function to prevent any real AGC voltage on the tuner until signal strength gets high per the manual.

Another clue- if I add a 9 volt battery to the pulse gate terminal that brings more voltage into the gate transistor collector and tap the connection I can see it shoot up to 10 or more volts. The HOT winding is so simple but for some reason I'm only getting a pulse of a few volts here instead of the 30-35 expected.

Last edited by Hagstar; 02-24-2017 at 08:44 PM.
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  #72  
Old 02-24-2017, 08:08 PM
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my dad bought a philco roundie back in 1964-65.sun tv and spanky mcfarland was there to help promote the products.philco ford with the blue tuning bars.set had a great picture,actually as good as the zeniths and rcas.we had that set for years,with very little trouble.sold it to a neighbor and they had it for years.i hit the crt a few times and it would hold up for about a year before it would fade.never another problem.the chassis ran on original everything for almost 25 years
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