CTC9 troubles

[Jonathan]

Do the brown molded capacitors have to be replaced in my Felton/CTC9? If you look at this you can see the brown molded capacitors. One end of the capacitor has a vertical line, does that indicate a foil side? What about the "Elemenco" guys, should I change them? There are also red molded capacitors too, which look like the brown ones, but usually a bit bigger in size, also having vertical lines at one end of the capacitor.

Must you completely recap these sets like you do the older ones?

And also, the top hat diodes used in the power supply as the rectifiers, will replacing those with a good 1N4007 give me more reliability?

One more thing. the 3.59MHz xtal in the chroma oscillator, can I replace that with a 3.58MHz HC49/U colorburst xtal and get better color or better performance?

Thanks.

Jonathan

[frenchy]

No you should not have to automatically replace those big brown or red shiny ones, reliable compared to paper ones unless you know you already have some symptoms that definitely point to one or it tests bad. The Elemenco ones seem to be a lot higher voltage on mine (1600 volts etc.) so they might be more eligible for replacement but I am not an expert on those. (Well I'm not an expert on ANY of them but ; ) Suspect caps in that set to me would be big black plastic ones with colored bands or tubular paper ones mainly. Especially ones like the smaller tan-colored paper electrolytic at the center of your pic.
You CAN automatically recap the big can electrolytics but I am less likely to do it nowadays the newer the set (like a '56 vs. a '66). You can gradually bring the voltage up on the set with the HV fuse pulled out and go easier on the electrolytic cans and reform them but I have never done that. Check to see if any get warmer than the others, they normally should stay pretty cool.
Unless they are leaking of course, then out they go.

I haven't had any problems with the top hat diodes in my CTC-10s yet but I guess replacing them would be cheap insurance as they can short.

The color crystal should either work, or not, so you don't have to replace it till that is determined. One of mine was dead.

I'd clean the rust off those tube shields at least where they contact the ground springs.

[Jonathan]

Frenchy,

I did replace two electrolytics so far, the tan colored one in the pic and the a yellow one underneath. Instead of bringing it up slowly, I'm going to recap the big cans too. I'll leave the other ones go because they seem a lot more reliable. I'll replace the top hat diodes, and see if the crystal works. And yes, I will clean the rust off the tube shields so they make contact.

Thanks again.

Jonathan

[oldtvman]

Originally Posted by Jonathan

Do the brown molded capacitors have to be replaced in my Felton/CTC9? If you look at this you can see the brown molded capacitors. One end of the capacitor has a vertical line, does that indicate a foil side? What about the "Elemenco" guys, should I change them? There are also red molded capacitors too, which look like the brown ones, but usually a bit bigger in size, also having vertical lines at one end of the capacitor.

Must you completely recap these sets like you do the older ones?

And also, the top hat diodes used in the power supply as the rectifiers, will replacing those with a good 1N4007 give me more reliability?

One more thing. the 3.59MHz xtal in the chroma oscillator, can I replace that with a 3.58MHz HC49/U colorburst xtal and get better color or better performance?

Thanks.

Jonathan

although the ceramic caps seem more durable than the paper caps, It's a good idea to at least replace all of the caps in the high voltage and sweep circuits. also the caps around the screen circuits go leaky and can cause all kinds of color drive problems. If you have a volt meter check all of the b+ power supply legs for proper operating voltages.

[Chad Hauris]

you can also use two .1, 630 volt caps in series, that'll get you .05 at 1260 volts. we have used this method to replace 1000 volt caps and it seems to work fine. The ceramic disk probably would be OK too, anything's better than those old paper caps!

[Jonathan]

Thanks guys. This Felton never came with an IF cover. I'll replace the caps in the HV section. Should I replace the caps on all of the screen circuits or just for the color drive section? Testing a cap involves removing it from the circuit, testing it's capacitance, then putting it back in, right? Quite a lot of work, but I'll do it if I have too. :P I'll definately look at the HV caps too. The elemenco caps and similar looking guys I'm going to change. The electrolytics are all changed.

One more thing, can I put in an IEC AC jack (the kind of power jack on computer PSU's and such) in the chassis and connect the earth ground to the chassis? Will this harm anything?

Thanks.

Jonathan

[blue_lateral]

Er... Well... I wouldnt. That doesnt sound like an easily reversible mod.

[frenchy]

Not sure these old tvs and radios where the chassis is the circuit ground and didn't have ground going to the power plug like modern stuff should be connected to earth ground or not, I would ask around some more on that before doing it.

[frenchy]

Originally Posted by Jonathan

Testing a cap involves removing it from the circuit, testing it's capacitance, then putting it back in, right? Quite a lot of work, but I'll do it if I have too. Jonathan

If I was going to unsolder one leg (if you can get the old one loose easily) and then go thru that testing, I'd just snip both leads in the same amount of time and spend a few more cents and a minute putting a new one instead. I am a layman at fixing this sort of stuff (ok I fixed record players for a year in a repair shop but that's it) so I figure I just replace caps to begin with when it's cheap and doesn't require any brains or test equipment. And you get a new part instead of worrying if the old one was almost ready to fail 8 ()

[Jonathan]

The original problem with this set was a dim, out of focus picture. One of the HV tubes had this white crust in a bellowed shape on the inner glass wall of the tube, where the part number is. I think this one got gassy, plus some other tubes in the HV section. The seller was the one who powered it up, but he was a TV repairman back then, so I feel he took good care of this set. The chassis was in good condition and everything was wired up the way it should be. He even had the photofact inside the cabinet. I was really lucky to come across this set and the seller.

From my electronics therory I have, connecting the earth ground of the IEC power entry jack to the chassis seems like it'll cause no harm. AC from the mains is completely isolated via the power transformer, and when I replace the line filter capacitors with AC rated safety caps, I see no reason why it wouldn't be pretty safe. Infact I'd probably prevent most AC related damage by earth grounding the chassis, like it's done on newer equipment. Also, the dinky power cord is thin and dinky, and really doesn't seem safe for a 375W receiver.

I realize that putting in an IEC power entry jack will take away some of it's character, but I also want this set to be as safe as it can be. That's why AC rated line filter caps are used in place of the older ones. It won't really do much physical damage to the chassis, just enlarge the hole so it fits, same with the back cover. Not only for the added safety feature, but the power cord can be completely removed, which I prefer because it doesn't get in your way when you remove it. I could get the two prong AC connectors too, and install it just as easily, but I thought the ground would add extra safety. Anyone know if I'll let the smoke out by doing this? Will I create a ground loop that will cause me major problems in operation?

Thanks.

Jonathan

[Chad Hauris]

I have an industrial model CTC-39 that has a grounded power cord as it comes from the factory. The socket is similar to the usual cheater cord only it has 3 pins.

When you hook up your new socket, the grounding lead (green lead or the terminal connecting to the ground prong) goes to the chassis. This will improve safety because the chassis can never rise above earth ground potential like if your power transformer were to short to the case..you'd end up blowing your circuit breaker rather than getting shocked by a "hot" chassis.

Only thing to watch out for is make sure all the components in there such as the tuner and CRT are grounded well to the chassis, so a voltage difference between metal parts can't occur. This is especially important in devices like jukeboxes where there are a lot of electrical sub-assemblies and if you grounded one but not another, the un-grounded one could have some leakage current that would give you a shock if you touched it and a grounded component at the same time.

Also a fuse in the power line would be a good idea, probably a 5 amp would be good....seems like this set has a circuit breaker in the B+ circuit but a fuse would be good extra protection.

[Jonathan]

Thanks guys.

Chad, Yeah, I thought I was right. I figured that would make it safer and save the set. I plan on having it plugged into a surge protector/line filter/circuit breaker strip when I use it. All of the goop leaked out of the power transformer because the chassis sat horizontal, you think that'll be any problem? I will also make sure that every part of the chassis is at ground potential. I'm just not sure what the best option would be--two or 3 prong IEC power entry jack. The two prong jack you see on an xbox, dreamcast, ps2, electric shavers, etc would be a drop in replacement and probably fit without any modification to the chassis (if I order the right one). The 3 prong IEC power entry jack would work too, and it would save the equipment if anything went wrong. The two prong jack in there is pretty worn from being in a shed for 30 years in LA weather, and it looks wimpy for the amount of power the set draws.

If you had a CTC9 and wanted to make the set safer and more reliable, and the AC jack was worn out, would you replace it with a two or three prong IEC power entry jack?

Thanks.

Jonathan

[radio63]

If you had a CTC9 and wanted to make the set safer and more reliable, and the AC jack was worn out, would you replace it with a two or three prong IEC power entry jack?

In my humble opinion, I really do not believe you should install a 3 prong or 2 prong IEC jack on your CTC-9. Nor should you make any other non-reversible modifications. You will be ruining the originality of it. Since you are concerned about safety, I would suggest doing something along the following lines:

Build a separate outlet-box with a duplex receptacle at the end of a sturdy three-prong power cord. Wire the outlet box with fuses and any additional safety items you wish to use. If you get a dual-type box, you will have enough room to wire in the fuse holders. Plug this into a power strip, surge protector or any other safety device you wish to use. Plug your TV into this box. If you really want the chassis grounded, you could run a separate wire connected to the chassis and the outlet box unit you will build. If you plug this into a grounded three-prong outlet, this will ground the chassis and you will not have modified the chassis irreversibly.

You mentioned earlier that you thought the original cord was rather thin. If that is the original cord, then that's what the manufacturer specified for that receiver. It should be adequate to carry the power load required for the set.

Just a suggestion. I understand your concerns but I feel it would be better not to do anything to it that is not reversible.

[Eric H]

Originally Posted by Jonathan

If you had a CTC9 and wanted to make the set safer and more reliable, and the AC jack was worn out, would you replace it with a two or three prong IEC power entry jack?

Thanks.

Jonathan

Since this is a transformer powered set I don't think it would help any to install a grounding plug, certaintly not one that would be so glaringly obvious.

If your really worried about it you could run a small piece of wire from the chassis to the center screw on your outlet, just like they do for washing machines.

They sell new ac jacks at www.tubesandmore.com , both polarized and non.

[Chad Hauris]

Originally Posted by radio63

In my humble opinion, I really do not believe you should install a 3 prong or 2 prong IEC jack on your CTC-9. Nor should you make any other non-reversible modifications. You will be ruining the originality of it. Since you are concerned about safety, I would suggest doing something along the following lines:

Build a separate outlet-box with a duplex receptacle at the end of a sturdy three-prong power cord. Wire the outlet box with fuses and any additional safety items you wish to use. If you get a dual-type box, you will have enough room to wire in the fuse holders. Plug this into a power strip, surge protector or any other safety device you wish to use. Plug your TV into this box. If you really want the chassis grounded, you could run a separate wire connected to the chassis and the outlet box unit you will build. If you plug this into a grounded three-prong outlet, this will ground the chassis and you will not have modified the chassis irreversibly.

You mentioned earlier that you thought the original cord was rather thin. If that is the original cord, then that's what the manufacturer specified for that receiver. It should be adequate to carry the power load required for the set.

Just a suggestion. I understand your concerns but I feel it would be better not to do anything to it that is not reversible.

I think often times the original manufacturer did not give enough concern to safety at all. These sets consume 350-400 watts and those flimsy power cords just aren't often good enough in my opinion. Ever see some of the 50's sets? No fuse protection at all. If the old cheater cord socket is broke or corroded etc you have to replace it with something, either a direct wire connection or another socket. My vote is for the IEC jack.