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  #16  
Old 03-05-2017, 11:07 AM
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zenith2134 zenith2134 is offline
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Ah, woodgwain eh? Yep that is the common color around here for that set, too.

I haven't had the best of luck rejuvenating these 12ers.. Usually they would come up like new and fad quickly with normal use.. Have recently exhibited this in a '74 Panasonic(which instant-on likely killed) and many others over the years.
Folks around here used these little sets as kitchen TVs apparently right up into the DTV transition. They were wildly popular and often have dead crts. FWIW, I use B and K testers/restorers exclusively, with the 466 being my go-to for most monochrome sets.
Regarding 'wrapping' the filament-Since the majority of SS chassis use fly derived filament supply, if you carefully put a couple of turns of addt'l wire around the flyback core and connect in unison to the existing hookup, you theoretically increase the typical 6.3v value by a volt or two. It can certainly open the filament if you go too wild with it. I average 8.something volts to elicit a brighter raster without blowing the tube open. I would not recommend this on a valuable set but it is a fine trick for the run o the mill jap 12" b/w..
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  #17  
Old 03-05-2017, 11:15 AM
WISCOJIM WISCOJIM is offline
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Quote:
Originally Posted by zenith2134 View Post
Regarding 'wrapping' the filament-Since the majority of SS chassis use fly derived filament supply, if you carefully put a couple of turns of addt'l wire around the flyback core and connect in unison to the existing hookup, you theoretically increase the typical 6.3v value by a volt or two. It can certainly open the filament if you go too wild with it. I average 8.something volts to elicit a brighter raster without blowing the tube open. I would not recommend this on a valuable set but it is a fine trick for the run o the mill jap 12" b/w..
Okay. It originally sounded like you wrapped a couple turns around the neck of the CRT. Couldn't make any sense of that.

.
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  #18  
Old 03-05-2017, 11:24 AM
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zenith2134 zenith2134 is offline
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Oops yeah I should have been more clear.
Back to the original post, What did the CTC-117 need? Only issues I've seen on that one were the metal filter can cap being marginal..that would cause a wavy pattern in the video. The crts that went into those early eighties color RCAs were pretty damn good in my opinion. My ctc-97 19" from '80 has many hours on it and looks fantastic still. someof the late seventies RCAs had really bad tubes however..had an old '77 CTC-89 with a stone cold dead blue gun and weak r and g as well. In fact, I am unsure when ColorTrak came out but the earliest ones all had guns with lost emissivity to the point where they couldn't be lined-up for proper monochrome pix. By the eighties (til say '85) I never saw substantial RCA weak tube syndrome
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  #19  
Old 03-05-2017, 03:32 PM
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The CTC-107 (not 117) works, it's just really dirty and the side is slightly melted.
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  #20  
Old 03-05-2017, 08:01 PM
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sampson159 sampson159 is offline
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there was a shop aprox 1 block from us.they would wrap every picture tube on every set.offered a 49.00 crt replacement.we got more than half of them in our shop.they were in business about 4 to 5 years before they shut down.some of those had 4 to 5 wraps on the flyback.many good crts were ruined by this practice.
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  #21  
Old 03-06-2017, 09:47 AM
zeno zeno is offline
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Crazy. We did some wraps & filament resistor jumps but only
the last resort. Best thing is it got the sets out of the
shop instead of abandoned...........

73 Zeno
LFOD !


Quote:
Originally Posted by sampson159 View Post
there was a shop aprox 1 block from us.they would wrap every picture tube on every set.offered a 49.00 crt replacement.we got more than half of them in our shop.they were in business about 4 to 5 years before they shut down.some of those had 4 to 5 wraps on the flyback.many good crts were ruined by this practice.
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  #22  
Old 03-06-2017, 10:23 AM
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Zenith26kc20 Zenith26kc20 is offline
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The vertical on the 86 is usually caused by bad 220K resistors on the vertical module. Change all of them. That set can produce an incredible picture when working right. We rarely saw those in here. If we did, it was vertical and tuner.
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  #23  
Old 03-06-2017, 11:19 AM
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Quote:
Originally Posted by Jeffhs View Post
Looks as if the channel selector knob on the RCA console is wrong for that model; may be a replacement for a missing one.
Looks just like the knob RCA intended - the set/knob on the cover of the RCA service manual looks just like Dave's.

Quote:
Originally Posted by Zenith26kc20 View Post
The vertical on the 86 is usually caused by bad 220K resistors on the vertical module. Change all of them. That set can produce an incredible picture when working right. We rarely saw those in here. If we did, it was vertical and tuner.
+1 for any set using the MDG module. There is also an axial cap, 22uF, that hangs off one of the supplies that will also cause some serious vertical issues, but always start with the 220K 1/2w resistors. The CTC85 and up sets were the first RCAs we sold new - and the modules at first gave everyone fits. RCA paid warranty only to the module level, but was short on modules, and so we had to troubleshoot the modules, unpaid, to keep some customers happy. Once you got the bugs out, those sets stayed gone for good, save for a lightning strike, or a "hot" Oak cable box that would eat the tuners. Cox had some fault cable boxes with upwards of 60VAC on the shield of the f-fitting. We saw only a couple, but scary....
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Last edited by Findm-Keepm; 03-06-2017 at 11:25 AM.
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  #24  
Old 03-06-2017, 11:35 AM
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Quote:
Originally Posted by Zenith26kc20 View Post
The vertical on the 86 is usually caused by bad 220K resistors on the vertical module. Change all of them. That set can produce an incredible picture when working right. We rarely saw those in here. If we did, it was vertical and tuner.
Thanks for letting me know. I was thinking it was a shorted transistor.
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  #25  
Old 03-06-2017, 03:34 PM
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Boy do I remember the early cable boxes. More than the Oak had 60 volts on them. I got to the point where I would "scratch" the cable on the F connector to see if a small spark appeared. If not, the customer wondered why the tech would jump when connecting them.
Overall, the 86 and the 40 were just about my favorite solid state RCA TV's. I always liked working on the 86. Also, I never remember changing a tripler in any. Zenith ate the lions share of triplers. Especially the wonderful early selenium ones!
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  #26  
Old 03-07-2017, 09:01 AM
zeno zeno is offline
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The CTC86 was a rare chassis to see. Always looked
good. Its the last RCA modular set. The 220K resistors
were also a common fail on the newer replacement "unitized"
chassis along with what looks like a vert out transistor
but RCA called it something else. The unitized kept us busy
with FBT's, audio, bridges & vert problems. The '86 seemed
to be very reliable but I thnks they built few of them.

73 Zeno
LFOD !
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  #27  
Old 03-14-2017, 07:07 PM
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Put a new vertical module in the CTC-86 today. Still no vertical sweep. Now I'm thinking the yoke is bad.
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  #28  
Old 03-14-2017, 08:06 PM
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Zenith26kc20 Zenith26kc20 is offline
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I may be remembering the wrong set, but look for a four tab electrolytic that is above ground and usually gray plastic covered. If I remember right, that set has a vertical output coupling capacitor. I remember changing a few. It may be hiding under the chassis and be a regular looking cap but I remember the twist lok....... I'll have to dig out a schematic when I get to the shop tomorrow.
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