RCA "Deluxe" Portable KCS-111D
 

Hi Guys, I'm getting ready to recap the video board if my $15 portable RCA. I've recapped several radios and a few TVs (love the early B&Ws) but I've not seen this particular cap before. The 1958 documentation I can find describes the capacitors as "paper" so I think I need to replace them but because I don't want to put more into this TV than I have to, I thought I'd ask you guys.

So... what do you think? Rev up the soldering iron and weed out the bad boys?

Thanks in advance, Scott

The maroon drops are marginal. In some sets they are all still perfect, and in others something like 1/3 are failing. I tend to give them the "innocent till proven guilty" treatment.

The black tubes are paper dielectric junk, definitely change them.

Same with the obvious paper you plan to change.

Change them all, that set is too hard to take apart to do it over. Those are all replaceable with the modern Poly caps.

There are some odd values in the vertical circuit and they are somewhat critical, also check the resistors for out of spec. Vertical has always been the hardest thing to get right on these for me.

Thanks Tom C. & Eric H.,

I really appreciate your comments. You are right, that board is too hard to access so I'm only going to do it once and replace the lot. Oh, and any resistors that have drifted is a given.

Hey Eric, I am curious about your odd values comment. I re-reviewed the cap tolerances and found what I think are your devices of concern. There are some .027, .033 & .056 paper caps between the vert osc and vert out sections that are 5% devices. Are these the values of caps that fall into your thinking?

Thanks again guys, Scott

Success!
 

Well... I end up replacing all the caps because only three tested within tolerance. Only one resistor was out of spec and even thought it’s a pain in the you know what to get to the foil side of the circuit board, I’m glad I did because now the TV works really well.

Thanks again guys!

Yes, .033 is a common value, but the other two are not.

The vertical height & linearity is so critical on these sets to start with it's best to use exact values.

Oops!
 

Hello again,

I think I spoke too soon. I got so excited with a stable and clear picture that I didn't notice that the width was way too wide. I attempted to adjust it but then I noticed that the B+ voltage was higher than expected (330 vs 275V) which drove the picture tube horizontal voltage too high (550 vs 480V).

My line voltage is 124VAC. I know that is higher than the designers expected in 1958 (110-120 is spec). I also replaced the selenium rectifiers with silicon diodes which added to the increased output. There's not much I can do about those two things but I am considering adding a power resistor in series with the B+ output to lower the voltage. Is that a good idea?

I am assuming that lowering the B+ will work because when I use an autotransformer to lower line voltage, I can get B+ and picture tube drive into the normal range at 100-112 VAC. That seems a bit low for the parallel heater string so I was thinking I could add a series diode to the heater string which will lower that string voltage but I am uncertain about how to adjust the B+ voltage.

Once again I am asking you guys for your thoughts.

Thanks in advance, Scott

Ok. After replacing the selenium rectifiers with silicon diodes, I used a 33 ohm 25 watt resistor to get the B+ voltage right at 275VDC when line voltage is 124VAC. The resistor is added right after the rectifier diodes and before the filter caps. It drops 12 watts and it is chassis mounted to help heat dissipation. I used a 50 ohm, 20 watt ceramic resistor and replaced the existing 18 ohm dropping resistor in the heater string. It drops 9 watts of power making the heater string right at recommended value of 103VAC.

Now that I’ve got that sorted, I need to figure out why the horizontal is too wide and the high voltage is too low (~10k). I’m pretty sure the 17DQ6A horizontal output tube or the 17AX4GT damper tube (or both) are just tired so I’ll just do some swapping to see if I can improve it. If not, I’ve got a good picture and I’ve got a case to clean and paint.

What do you guys think?

These were inexpensive sets back in the day, some overscan was not uncommon and most did not have a way to adjust the horizontal width.

How wide is it? I don't mean to insult, but you are using a 4:3 source for the video?

Low HV will generally make the raster larger in all directions, the vertical can be adjusted to compensate but not the Horizontal.

Do you have a Variac? if so try cranking the line voltage up above normal and see if it improves.

Hi Eric,

Not insulted at all. Just trying to figure things out. Thanks for the suggestions.

It’s overshooting about 15%. There is a horizontal width adjustment but it’s all the way at one end. It’s an adjustable coil in parallel with a portion of the flyback. From what I can tell, it’s pretty standard stuff for the era. It’s tied into the 615v boost but it’s running low (~575V). My thinking is the coil de-tunes that portion of the flyback reducing the deflection thus controlling the width. I am not sure. What I do know is both the high voltage and the boost voltages are low and it seems that the 17DQ6A controls that part so getting the right values should be achievable. Maybe not. Like I said, I’m still learning.

Does any of that make sense? Am I delusional?

Oh, almost forgot. Yes, I’ve tried using my variac to simulate voltages. I am reluctant to increase much above 130VAC because the high voltage really does change all that much when I increase it. However, when I lower it to 110VAC, dropping B+ to about 230VDC, the width reduces to the point where I can properly adjust it. The filament string drops to around 80VAC and all tubes run about 25% low. I’m guessing that might improve tube life but then again, I’m not so sure.

Thanks again for your thoughts. I really appreciate it.

Sir, I would like to know why it is that if you are working on a vintage TV from about the same time period as mine, why you had to go into my thread and just randomly give me a whole "enviromental" shpeel about why its bad to use dim bulb testers and that I need to "keep up with the times"?

It seems to me you're working on your TV the same way I am.

Which by the way I was only using the advice given to be by others on here so don't go shooting the messenger.

So I would like to know why it is you're trying to cause trouble on here when no one was trying to cause trouble with you?

With all respect, what got me whipped up was the political aspect of your comment and the willful disregard of why the regulation was put in place. You brought in the comment that the President corrected this stupid law. I disagreed with you and voiced my opinion. Yes, We are working on similar things but just like using modern components in an old TV or radio to breath more life into these beautifully crafted machine, we should not long for this old technology to replace more efficient designs.

I work in the power industry and these small but important steps will help us all in the very near future insure that we all have the kind of power we want and desire. If we keep using incandescent lamps as our primary lighting, we will not be taking advantage of the knowledge we have to do it better. My comments were designed to suggest that the regulation was not stupid and we can still enjoy our hobby by being a bit more creative. If you think I was causing trouble then you missed my point and I apologize for not being a better writer.

I hope that helps but if you want to discuss this further, we should probably move this to a private session.

I kind of doubt a hand full of hobbyists utilizing dim bulb testers is going to create a national energy crisis. ;) Sometimes it doesn't make practical sense to utilize modern technology to replace something so simple that's been working reliably for decades, which is why most of us still utilize wheels to get from point a to b. Technology isn't bad in itself so much as are often the motivations behind marketing it to the masses.

I sent you a private message, complete with a video backing my views on this and if you wish to actually discuss this through private message, then I suggest you reply to my private message I sent you, otherwise I'm going to assume that you were just making that comment in my thread just to troll with no intentions to "correct misinformation".

+1 :thmbsp:

I agree I think he was overreacting when he posted his comment in my TV repair thread.

;) And at this point now I think your overreacting , the Man made his comment , you responded to it , it's now time to do like Elsa and "Let it go" ....

:saywhat: That is , unless of course your looking for an internet dustup , in which case by all means continue . Just remember the guy Levi ("CaptainClock") who posted very suspiciously like you do got banned here for the very same thing , not knowing when to walk away from what is really a pretty minor issue in the grand scheme of life

I'm not trying to start anything or keep anything going, I just find it frustrating that the OP of this thread decided that he would make it his life's goal to try and convince people on here (on my thread of all places) that dim-bulb testers are somehow bad for the environment.

Which if he wanted to do that, should of just started his own thread elsewhere in the forum to discuss that topic rather than spamming my thread with his topic.

I'm not trying to start anything or keep anything going, I just find it frustrating that the OP of this thread decided that he would make it his life's goal to try and convince people on here (on my thread of all places) that dim-bulb testers are somehow bad for the environment.

Which if he wanted to do that, should of just started his own thread elsewhere in the forum to discuss that topic rather than spamming my thread with his topic.

And on that note I'm going to stop while I'm still ahead.

:thmbsp: Cool , may the vacuum tube Gods bless us all and may our bulbs be dim and our CRTs bright :D

Gentlemen,

My name is Scott. I grew up in the '60s and '70s, got my electronics degree and have been working on modern 3 phase UPS systems for more than 30 years. About 10 years ago I built an Internet radio and picked up a TeleTone AA5 to house it. I looked at the removed chassis and figured out what was wrong with it and that started my fascination with tube electronics. I've restored several radios and TVs since then acquiring (and restoring) vintage test equipment along the way.

I am not trying to keep this going but it was never my intention to slam anyone other than the "Stupid Law" comment. I attempted to respond to the portion of vortalexfan's thread after Electronic M made the comment but I did not realize that my comment would be added to the end of the thread. That made it appear out of context which I now understand.

I obvious agree that the 2007 EISA decision restricting 60 watt and lower incandescent lamp production based on efficiency is a good thing. It does not mean you can't find these lower wattage lamps. It simply means that your typical source for these bulbs will likely dry up because marketing LED replacements are becoming more popular. The reason I commented in the first place is I was following vortalexfan's troubleshooting of his Meck TV and wanted to encourage a more sophisticated approach. I have re-read the thread and I now realize that not only was he struggling on some of the most basic troubleshooting concepts but his financial situation could not support my suggestion. I apologize for misreading the thread and writing a comment that was easily misunderstood.

I have benefited from being a videokarma member for more than two years and I'm hoping to regain trust from the membership.

With respect, Scott

;) Speaking for myself only , because it's not my place to speak for the rest of the membership ;

I don't believe you've lost any trust here , you sure haven't lost any with me ! People have small disagreements on internet chat forums all the time , it happens , and we are actually truly blessed that the disagreements here don't rise to the level I see on the model airplane forum I belong to (Pick just about any thread at the RC Universe "AMA discussions" subforum to see just how ugly internet dustups/trolling can become) . An off topic side comment was made , you posted your view about it , and that in itself is no reason for people to distrust you . Now if you had come in with figurative guns blazing tossing verbal bombs everywhere sure I could see folks taking issue with that , but I'd hope we as a group DO have the mutual respect to accept that there WILL be disagreements on various off topics and not go holding lifelong grudges over such small issues .....

Oh, wow! I haven't been an AMA member since I got my pilot's license in 1999. I can only imagine how that would be. As Roseanne Roseannadanna used to say, "It's always something!"

Thanks for the kind comments.

I stocked up on incandescent bulbs when I learned about the ban, and now I have a closet shelf full of them. But I bought LEDs anyway, to save on utility costs, and my stock is unlikely to ever be fully used. Incandescent bulbs do certain things their replacements cannot do, but I probably only have two or three left which I use semi regularly.

I switched because a better product appeared, not because the old one got banned. I believe the same thing could have been accomplished though tariffs and subsidies instead of an outright ban, which had the side effect of making non energy intensive specialty uses of incandescent bulbs harder to accomplish due to lack of supply.

That said, I suggest a variac plugged into a kill a watt instead of a dim bulb. I think dim bulb testers are more use for amateurs troubleshooting audio equipment - I have never seen a pro tech use one.

Do You still fly ? I got my FAA A&P mechanic's license back in the early 1980s (now blissfully retired) and although I never did get a Pilot's license I have considerable stick time doing "check rides" of repaired aircraft . The RC models are a great way to keep the old brains sharp , although my aging eyesight will eventually end that , it sucks getting (gotten ?) old . An interesting side topic , do you know that the FAA is now requiring RC model pilots to get a pilot's license ? Due to the huge expansion in the drone hobby the FAA decided that all pilots of "UAS" (Unmanned Aerial Systems) have to be registered , with a knowledge & skills test to be rolled out sometime in 2020 . Kinda weird times for sure when pilots of what the general public sees as "toy airplanes" need a pilot's license ($25K fine for getting caught flying anything over 2 pounds without one) but with the risk of a drone , operating beyond it's operator's direct line of sight , taking out a full scale aircraft , the FAA was forced to do something .

God bless Gilda Radner , it IS always something :thmbsp:

I do still fly. In fact, my BFR is scheduled for tomorrow if the weather holds. It's always tricky this time of year. I used to fly RC for years before jumping full scale. I was active in a Pontiac, MI club for about a decade. You know the drill: build in the winter and fly in the summer. I still have a giant scale and three of four park flyers but I am sure to be really rusty. It is amazing the progress in LiPo technology since I was active.

I was into building drones before the corporate world took over. It was fun being part of the hardware and software development but my two home built drones are way behind the times. I do have one of my drones registered with the FAA but I did not hear about the pilot licensing requirement. I know there is a regulation and airspace operating requirement for drone pilots operating in controlled airspace outside a AMA sanctioned field and that's something I support but it does surprise me if that extends to a local flying field. I have a good friend that makes a living as a drone photographer but I've never heard him talk about having to have a pilot's license. At least not in the traditional sense. You've peaked my interest. Now I must investigate.

Hi Guys,

I've been struggling on how to fix a horizontal width issue (way two wide) and I stumbled upon a solution but it worries me. I was testing C106 and forgot to re-solder it and all of a sudden, I have good width control via T4. I've not replaced C106 for leakage (I can test up to 450V) but I've substituted an equivalent arrangement of multiple capacitors and with the new arrangement, the problem returns. I've not replaced C106, R106 or C107 but I'm not sure they are the problem. With C106 left in place, the best width I can achieve is about 10-15% overshoot with the T4 slug fully retracted. With C106 out of circuit, I can adjust T4 to a midpoint and achieve a normal width picture.

I've looked through Grob's, Basic Television Principles & Servicing but nothing quite matches the example designs and this RCA. Has anyone run into this issue? How about the purpose of C106? It looks like some kind of boost bypass to one side of the yoke but I'm not sure why. Second question, can you think of any long range issues keeping C106 disconnected?

Thanks in advance, Scott

Yes , right now the FAA is finalizing the requirements for recreational UAS users , you friend being a professional drone photographer is already bound by a more stringent rule set known as Part 107 . Part 107 requires a pre filed flight plan for all commercially operated UAS flights , already has a knowledge and skills test if I recall correctly , as well as a remote identification requirement to be enacted sometime in 2020 . Like you said and I can't blame them one bit , the FAA had to take action before a drone takes out a full scale aircraft , but my own opinion is that RC aircraft being operated within their operator's direct line of sight are not now nor have ever been the same collision risk as an RC aircraft being operated by an operator using remote cameras to conduct the flight . "See and avoid" has worked well for traditional line of sight RC model flying for many years , it was the advent of the remote cameras where the operator no longer actually sees his RC aircraft and what's near it that got the FAA's notice .
https://www.federalregister.gov/docu...rcraft-systems

Back in the 1960s, they sold a device that went between the damper tube base and its socket, placing a capacitor between the plate and the cathode of the damper tube. The device was used in cases when you didn't have enough width. They came in two values, standard and extra width gain. I suspect C106 is doing something similar. One thing I would check is the value of the 650 V boost line both with C106 in and out of the circuit. If it is close to 650 V with C106 removed, you should be OK to leave C106 disconnected.

No harm leaving it out if that gives you the width range you're looking for.

I think that C106 may form a resonance with the flyback winding. That could make sense that it would effect the width. May effect the boost voltage and HV also. Is there a chance that the flyback was replaced? Did you confirm the original value of the cap? SAMS has been know to make mistakes.

Hi Guys, Thanks for the feedback. I was thinking C106 might be part a resonant circuit and by removing it reduces width but I'm still wet behind the ears on these things. Cap is very close at 127 pf. Boost is a little high at 640V and HV is right on spec at 14KV. Voltages don't change with or without cap. I don't think the flyback has been changed.

This set was all original when I got it with the exception a few non-original tubes and someone adding what appears to be some bypass caps from a few tubes B- points to the RF shield on the back side of the main board. I wasn't too impressed with the workmanship so when I recapped it, I put it back to original. That was the major fix.

Thanks for the help!

I'm no expert but I believe C106 is basically in parallel with the width coil(T4) so I would suspect it was included to increase the width by partially cancelling the effect of T4. So long as you're getting the desired width I wouldn't worry about removing it. If you're curious what it's doing you could even play with it's value. You may see some change horz linearity. Most everything in the horizontal circuit interacts to some extent. Oh, I've been an active fixed wing RC'er for about 45 years.:thmbsp:

Do you guys ever hang out on RCGroups?

I have over the years, along with Flying Giants. Not so much the last few years. This whole FAA fiasco has everybody so up in arms over all the hoops we're expected to jump through. I grew up hanging out with my dad who taught me to fly, I think it was about 1972. I consider it my mental therapy now, and lots of good memories.

Hello Scott, I'm very sorry I misunderstood your post, and I am also glad to know that you were fascinated by my TV Thread, which I'm still having some issues with (mainly Tuner and Video IF alignment issues).

I didn't mean to upset you, and I'm really quite new to working on antique TV sets (although I have serviced many solid state TVs from the 1980s and 1990s and even Flat Panels without too much issue).

I'm more experienced in repairing Tube Radios and Record Players (not as complicated to troubleshoot and not as much to go wrong with them as TVs).

I just wanted to try my hand at an old tube powered TV because I've always wanted to have one to watch period movies and TV shows on, but even this lower end Meck TV has proven to be a nightmare to work on as you could see from my thread.
Although it doesn't help matters any that my Meck TV had sat in an old abandoned farmhouse that lost its roof over 20 years ago prior to the person who I got it from finding it.

I have been working on vintage electronics (tube and solid state) since I was 13 and I'm 31 now, and my very first repair was a 1985 vintage Montgomery Wards 13" B & W TV that the Vertical and Horizontal hold was screwed up on it and all I did was readjust the horizontal and vertical hold controls on the back of the set and it worked perfectly for the 5 years I had it (before I was given a 1988 Zenith 13" Color TV that had the best Picture I had ever seen on a color TV up to that point), and I had that TV clear up until just before the DTV Conversion when I then donated it to Goodwill (back when they were still taking CRT TVs, which the Goodwills near where I live all quit taking CRT TVs arount 2014).

We’re good. Things got a bit out of joint but we found our way back. Thanks for the kind words.

I know what you mean about learning B&W TV alignment. It almost more art than science. Specific tube makes can matter and many passive components matter more than you think they should. A good sweep generator with markers helps a lot but I think practice helps more. I keep a Motorola 9VT1 running. Those early sets teach you a lot. Mainly patience and humility but eventually your skills improve.

On February 1 in Farmington, MI will be the annual Winter Vintage Electronics Expo of the Michigan Antique Radio Club. There will be a ton of radio deals and usually a fair number of vintage TVs that need attention. I’m not sure what part of Northern Indiana you live but if you have a few sets to sell, looking for test equipment or are interested in buying something to work on, it’s a good show. I’ll probably share a table with someone (saves a few bucks) let me know if you are interested.

I live near Bristol, Indiana which is about 7 miles from the Michigan border with Indiana, and I've heard of Farmington, MI, which I believe is a suburb of Detroit and I'm about a 3 1/2 hour trip out from Detroit, Michigan where I live. I would have to have someone give me a ride if I were to go to that show, because I'm not too keen on driving around Detroit by myself.

I do have a Westinghouse WR-10A AM Only Tombstone Radio that I would be interested in selling that I had fixed up.

You are right, Farmington is a western suburb of Detroit. I used to make a monthly drive down to Coldwater. I'd guess it's more like 3 hours. Interstate the whole way. Pretty easy but it's a drive. If you make it, let me know. I'll keep a space available for you. By the way, what's your first name?

I've been missing Posts over the holidays including this post, and have yet to read the one that bothered vortelexfan (who for months I've been certain is a particular other member he has been accused of sounding like, but I won't go into specifics as I don't feel it needs my attention presently).

I want to logically justify my position in saying it was a stupid law before.
I'm a free market favoring capitalist and a DXer, among other things, and that law hacked both of those aspects of me off quite a bit.
First off as an American adult I feel deeply offended when something benign is made illegal to sell to me. Also I see global warming/climate change as nothing more than a Marxist strategy to destabilize and sieze big brother style control over our ecconomy. Marx himself proposed killing capitalism by getting the public to attack industry for pollution. Climate change has never been on solid ground scientifically, virtually all predictions especially the alarmist ones that have passed their it will happen by date have not come to pass, and there are many predictions that are in conflict with other such predictions...In short I believe it is all a bunch of hogwash made by politicians, scientists with overriding political motives, and scientists funded by politicians trying to please their source of funds...
I believe that as long as I pay for the energy I use and find some personally defined benefit in the way I use it then I should not be bound by someone else's efficiency standards.....If the opposite happens and consumer energy use regulations tighten we will likely eventually be banned from using our tube electronics based on their poor efficiency (and that prospect should bother all of us).
As a DXer and Licensed Ham radio opperator the proliferation of man-made radio noise in recent decades has bothered and hampered me greatly... non-incandescent lighting seems to be the most common source behind switch mode power supplies (that often are components of said lighting) which are also proliferating. I chose to use as little non-incandescent as possible to minimize the RF noise and I really wish we would all just go back to incandescent and 60Hz linear transformer supplies to reduce man made RF noise....I suppose an alternative would be for the government to completely ban the manufacture and import of noisy devices and force the alternative lighting solutions to get their noise problem under control, but the government doesn't seem to be interested...

I could also argue about the difference in actual light quality and that there are plenty of fixtures out there that don't properly support modern bulbs or look silly equipped with them but those arguments are IMO obvious.

The above represents my personal opinion. It is not intended to offend but rather merely to offer insight.

Can you explain this more specifically? I'm legitimately curious as to which climate predictions have passed without hitting or bypassing estimated targets.