Hello,

I'm restoring a RCA 630TS clone, an Air King A1000. I replaced every electrolytic and paper crapacitor with modern ones, added AC line supression caps in place of the old micas for safety and RF noise supression. I may replace the mica coupling caps in the Video IF section if they are bad. Since all the work is done underneath, I need to figure out how to mount the flyback.

When I received the TV, three recifier tubes were missing from the HV section, and the flyback was free moving inside the HV cage. I removed the cage and I'm unsure how to mount the flyback securly. I can't really figure it out. Is the flyback mounted on the HV cage somehow or is it mounted to the chassis? I think the flkyback is good. If not, I have two other good 211T1 flybacks for a 630TS or clone. I purchased all the missing tubes, and just need to assemble it and put the CRT back in to see if any smoke will come out or not.

If anyone has any ideas, please let me know.

Thanks again.

Jonathan

The fly should have 4 screw holes on the side.
It attaches to the side of the HV cage.

Eric,

Thanks. I'll put it together tonight.

Jonathan

Ok, well, I got the set together, powered it up and I get no raster. All tubes light up except the high voltage rectifier that is plugged into the socket that stands off from the chassis. I attempted to discharge the CRT by connecting a wire to the chassis and to a screwdriver, and touched the anode, but I never got any spark at all. Does the HV rectifier tube have a filament that is easy to see glowing?

Also, what is the Lamp in the HV section for? It it used as a fuse? A #47 type lamp was in there, but I replaced it with a #44 lamp. Both don't light up, and the #47 lamp I took out has a good filament. Is it suppose to light?

I have a good flyback for this set, but just wanted to know what to do before I put it in.

Thanks.

Jonathan

Well, there's a couple of possibilities. The flyback may indeed be bad, which would explain why some previous owner had removed it from it's mountings. Or you could have any number of other problems contribuiting to a lack of high voltage or lack of raster. Do you get static on the screen? By that I mean, can you put the back of your hand up to the face of the tube and feel the static? You may be getting high voltage, and not even know it. Try this - turn out all the lights in your workshop and then turn on the TV, and watch the screen carefully. If the CRT is really, really, really dim, you may be getting a picture, you just can't see it because the smallest amount of light washes it out. Another test for high voltage is to get a small neon lamp, and tape it to the end of a pencil or other non-conducting stick. While the set is operating, hold the lamp near the CRT anode connection. Typically, the lamp will glow in the presence of high voltage - it doesn't even need to have leads on it. It's the charge that excites the gas in the lamp. Of course, this is a small screened, immediate postwar set, I haven't worked on anything quite that old. It might not have enough HV to detect like this. That's also an electrostatic deflection tube, right? Haven't worked on anything with electrostatic, so I'm not sure what all will apply and what won't. Good luck, and hopefully, someone who knows more about the set in question can give you some more useful advice!

-Ian

BTW - in reference to your other question about pilot lamps as fuses. I have seen #44 or similar pilot lamps used as fuses before, I think there was something about them that was more desireable than a normal fuse, don't remember if it was that they typically acted faster, or the added resistance or something, but I know I've seen it done before. Once again, I haven't worked on a set like this before, so I may not know what I'm talking about :) I'm just trying to be at least a little helpful, as well as keep myself busy early in the morning :)

-Ian

You can use the neon lamp taped to a non-conductive stick to check out the different parts of the HV system...first hold near insulation of Horizontal output tube plate lead to see if there is HV AC there...then you can move it to the plate of the rectifier. I don't know if it can detect the DC from the output of the rectifier but I know it can pick up the AC at the horizontal output plate, the yoke leads, and the HV rectifier plate lead.

This is for a traditional magnetic deflection set...if it is electrostatic it will use something like a 12AU7 for the horizontal output tube and use a seperate tube as an oscillator for HV.

The lamp may be a cathode fuse on the horizontal output tube...I have installed lamps like this in color sets. In sets having a horizontal efficiency coil you can adjust it for minimum current by adjusting for minimum lamp brightness.

630TS, a 10-incher, is most certainly a magnetically deflected CRT set. So, in fact, is the the 7" 621TS.

Johnathan,

Ifrst, ohms out your flyback for continuity. If it is ope, it is bad. If it is not open, it is likely good. Flybacks generally fail in one of two ways....1) they go open circuit somewhere, in which case nothing much happens, buy you have no high voltage and no raster. Or 2) a short developos between adjacent turns on one of the windings, or the flyback begins to arc, due to dirt or contamination on or inside the flyback, in which case the failuse involves arcing and a very obvious catastrophic failuse.

The pilot lamp should be replaced with a fuse of the proper size. But, when troubleshooting, sometimes a lamp can be used in place of a fuse, as it acts as a nonlinear resistance. It presents a very low resistande when operating with currents well below its rating. Should a faudt develop in the load circuit, causing the lamp to draw rated current, the lamp fialament heats up, becoming a large resistance, and reducing the voltage to the load, thus regulating the overload current draw to some extent. This is only recommended when troubleshooting while searching for short circuitsd or overloads, and is not a technique I recommend.

If your flyback has continuity, you shoud check to see if your horizontal oscillator is operating. This is done easily with an oscilloscope. No scope? Then check the bias on the oscillator tube....if it agrees with the RCA schematic, the oscillator is running. You can often hear the 15Khz whine, if you have adequate auditory bandwidth.

If the oscillator is running, check the bias on the horizontal output tube, make sure the damper tube is good, and make sure the yoke has continuity.

Good luck!

FYI, from my experience the neon lamp only works on the AC side, not the DC output. A neat trick. Also, if you have HV but no raster check the ion trap (assuming this set still has one-if it used a later aluminized tube as a replacement then it might not) the trap would not have to be far out of adjustment to kill the raster.

Hello guys,

The lamp does not light, I get no static electricity from the front of the CRT, I hear no flyback whine, and the lamp does not light. The HV rectifier doesn't seem to light either(is it suppose to?). The horizontal damper (5V4G), horizontal output (6BG6G), and the high voltage rectifier (1B3GT) were all missing, so I purchased some new ones and installed them. Since I recapped everything and installed new tubes, I think the next thing to do is to install the good flyback. I'll check resistance tonight.

Thanks.

Jonathan

...

Also another check is to pull the plate lead off the horizontal output tube (with the set unplugged) and hook up the voltmeter to the disconnected plate lead. You should read the B+ voltage at the plate lead. This checks that the flyback primary portion of the winding and the damper tube is operating.

Ok guys, I have an update.

Last night I checked the resistances of every winding on the flyback except the HV winding. Every winding was in spec. The flyback is good. I then went over my recapping and saw that I made a mistake. I connected one of the caps to the wrong terminal on ther tube socket. After fixing that, I checked B+ voltage on the H output tube. It was 30 or 40V below what it should be. I then suspected the 680k plate resistor so I measured it and it read 2.1M! It drifted quite a bit. I never got any farther because I had to leave for work. I'm going to replace it when I get home and check more plate resistors. I checked the voltage on the top electrode of the horizontal output tube in respect to chassis ground and my volt meter measured a little more than 400V as it warmed up. After it warmed up, my meter would beep and go nuts, even though it's set to 1000VDC/750VAC. Silly me, thinking that the resistors would be fine.

I suppose the best thing to do is check all the resistors and replace all that are more than 20% out of spec?

Thanks.

Jonathan

Another test for high voltage is to get a small neon lamp, and tape it to the end of a pencil or other non-conducting stick.

Careful! A pencil has a conductive core, namely the black part that does the writing. It's graphite, similar to carbon comp resistors. Not good for use around kilovolt high voltages.

Ok, well, I replaced the resistor. I then turned it on without the HV rectifier in place, mistakenly forgetting to put it back. I hear a pop, I then immediately turned it off, then I smelled something like a resistor burning. I lifted the chassis up to see nothing burned underneath. So, I then put the rectifier in and still got no raster.

So then I got a green neon bulb and taped it onto a plastic multicolored retractable wand that screwed onto a flashlight. (My brother and I used to hit eachother with it when we were little :) I turned it on and it glowed green when I placed it by the socket/standoff of the HV rectifier, the cap on top of the rectifier, the cap on the top of the H output tube, and the 1st and 2nd winding connections that connects to the caps.

After leaving it on for a while and seeing the neon glow, I turned it off and touched the HV rectifier and it was cool, not hot like every other tube. It could be bad, or the resistors under the HV rectifier socket could be bad. I'm just not sure. I'm sure that since the neon glowed, it means that the H output and rest of the horizontal section might be good enough to produce a raster.

So then I realized I missed a connection on one of the terminal strips. Appartently I never checked it over as much as I could. So I fix that and try it out. The fuse lamp lights! I put everything together and still no raster. So I got a #44 lamp and connected it to the filament pins of the HV rectifier. I turned it on and it glowed too. I put the HV rectifier back in and still no raster, it never even got hot like the rest of the tubes did. I checked the resistance of the filament and I measure 1.6 ohms.

Could the 1M resistor that is in series with the high voltage DC be open? does it usually fail?

Thanks.

Jonathan

There have been cases of resistors that are in the HV output going bad, so if there is one it may be a suspect. The check for HV DC is to unplug the set after operating it and discharge the CRT anode to chassis ground...if you get a spark then you know the DC portion is working.

Does this set use an HV filter capacitor (round cylinder with screw terminals on each end, and connected to HV line)...it could possibly be bad. If the tube uses a graphite coating make sure the outer shell of the tube is grounded to the chassis.

Also don't connect the meter to the horiz output plate lead with the lead connected to the tube, only meter the lead with it disconnected...there can be up to 5KV AC pulses at the plate of the H.O. tube when the flyback system is operating which can destroy the meter. With the plate lead disconnected, you are only measuring the DC from the B+ supply.

...

Ok, well, I checked underneath the HV rectifier socket. The 1M resistor measures to spec. I can't get a measurement of the 3.3 ohm resistor because it is in parallel with the filament winding of the flyback. I exposed one of the leads on the neon lamp and touched it to the cap of the HV rectifier and it did spark and the lamp did glow.

Underneath the HV rectifier socket, the one of the wires from the filament winding was touching that metal ring. I'm going to hot glue it in place where it won't touch anything.

This set does have the HV capacitor. It was held to the chassis by a spring and a tension ring (I think you'd call it a tension ring, the other RCA 630TS clone set had the lugs of capacitor threaded, I misplaced it and can't find it anymore) so I have it held in place with a bit of solder and a short lead that is soldered onto the chassis. I was told that this cap rarely fails, but I purchased a 470pF 15kV axial leaded capacitor just in case. Would this work if the original 500pF cap is bad?

What is the purpose of the metal ring, and what is the purpose of the HV rectifier filter?

For now I'll glue the wire out of the way and hope for the best.

Thanks.

Jonathan

Well, I glued the wire and put back the HV rectifier, powered it on, but still no raster, however, HV DC is finally working (I think). When I discharge the anode, I get a spark. It's not a big spark, but seems big enough to hurt. I suppose this means the flyback section is finally working. When I discharged it, I saw a spot on the CRT light up too. This a good sign?

I still get no raster though. So I guess I must turn my attention to the video section, yoke, and focus coil. I don't think this set has an ion trap, it does not say so in the photofact. The CRT is pushed all the way in, with the two "U" wires touching the CRT. The yoke and focus coil are securly in place. The anode connection is on the top. The CRT is held level with the holes in the yoke and focus coil with a cardboard box and a memo book, so as to not put any stress on the neck and have it implode and ruin a very desirable and rare CRT.

Since there is no raster, should I turn my attention to the video section? Should I test for any bad resistors and make sure there is enough B+? The sound section doesn't really work except the amplifier, so I get static and hum, but nothing like static you get when you tune a frequency that there is no station. With a satellite receiver connected to it, I should get sound on channel 3 if the sound section is working, but it isn't.

Right now, I'm concerned about the raster, then I'll work on the sound.

Thanks.

Jonathan

...

Careful! A pencil has a conductive core, namely the black part that does the writing. It's graphite, similar to carbon comp resistors. Not good for use around kilovolt high voltages.

Good point... Anoter fine example of me just needing to shut up... You're right - I hadn't thought about that. I had always used a lamp taped to the barrel from a plastic BIC pen, I guess when I posted I thought that "pencil" would also work. But yes, graphite is conductive, and while I'd hope that the amount of graphite in a pencil should act as a large enough a resistor to protect one from getting zapped(much), it's much safer to just ignore the things that I post :)

I like to think that I know what I'm talking about, but I guess I don't think about as much as I think... I think then therefore... Oh the hell with it. I'll shut up now.

-Ian

Hey, I'm a real scaredy cat...got a 3 foot long ceramic rod-I guess it was out of some bathroom fixture or something-& I use that for cases like this. Just tape the neon lamp to the end & go exploring, or go tapping or whatever needs doing. Actually, the last couple times I did the neon test I just took out the whole drawer of neon lamps (out of one of those clear plastic Akro-Mills cabinets) & hold it close. Get all kind of glowing, nice & safe.

As for the tv, I would definately settle the ion trap question first. I know they don't have to be very far out of adjustment at all to kill the raster. If no luck dive into the video circuit, sez I.

I think I am missing an ion trap. The CRT that my Air King A1000 has is a 10BP4 from RCA. I think the inside of the tube is a dark color; the same color as the outside graphite coating, and not the aliminized coating required to operate without an ion trap.

It's odd though, because Just like the Dewald BT100 I got from ebay(another 630TS clone set), it came with broken H output and damper tubes, as well as a flyback with the mounting clips broken off (but it tested good with a DMM for resistance on every winding, so it is good). It also came with a deflection yoke and focus coil, but no ion trap. I am not sure if the inside of ther CRT is aluminized, I doubt it though. Both these sets came in similar condition. Both have no ion trap (though the ion trap is not at all mentioned in the photofact of the Dewald BT100 or the Air King A1000), and both came with the HV sections taken apart in a similar manner, with the H output and damper tubes either missing or broken, both flyback mounting clips broken off, and both good flybacks. Both also use the pilot lamp fuse in the HV section as well.

Also, this set (the Air King A1000) has a electrodynamic speaker with field coil use as the speaker magnet. In the photofact, it has a seperate 1H 300mA choke mounted on the botton of the chassis. I honestly perfer this than the electrodnamic speaker, so I ordered a 1H 300mA choke from Hammond (Hammond part number 158T) and am awaiting an audio transformer so I can use a modern speaker. Wonder why this Air King set used an electrodynamic speaker?

Anyone familiar with these 630TS clone sets made by radio manufacturers? Air King and Dewald made only radios, and probably in the late 40s they used RCA's 630TS chassis and cabinet designs to get some of the TV market.

Thanks.

Jonathan

The ion trap is mounted on the neck of the tube between the bakelite base and the yoke. It can be a small magnet held on with a spring or it might be an electromagnet, which is hard to miss because it's so large.

The 10BP4 requires a trap, the 10FP4 is aluminized and doesn't.

This picture from eBay is supposed to be a 10BP4 but I think it's an FP4, look closely and you can see the shiny silver coating inside the glass between the screen area and the black dag coating, you can also see the shiny stuff around the anode connector.

I GOT A RASTER!!!!!! :) After looking in the garage for the PM ion trap, I realized my Air King did infact come with one. I took it and put it between the base and focus coil, and moving it around I FINALLY got a raster. I moved it around until I got the brightest picture. I adjusted the vertical and horizontal controls to get a picture that filled the whole screen. The only thing I see on the screen is horizontal and vertical retrace lines and nothing really more. I'll probably need to go over the horizontal and verticle sections so I get a stablized picture. The correct picture should be snow, right? There are no VHF channels in my area, so I'll use a satellite receiver to test it on channel 3.

Are these symptoms I'm having any indication of one single problem or a ton of little ones. I'm a TV newbie so I'm not honestly sure.

Eric,

Yeah, I saw that on ebay, it probably is aluminized. This 10BP4 in the Air King is nice and bright, but I might bid if I can afford it. :)

Thanks.

Jonathan

Turns out the first video IF tube socket is bad. When I move it around I get audio and a raster with something on it. It's the 6AG5, the 1st video IF amp. What happens if it's removed? Will it give me a blank picture? In that case, the horizontal and vertical is still screwed up, as I can still see scanlines. Should I go ahead replacing the resistors more that 20% out of spec?

Thanks.

Jonathan

Eric H,

Upon looking at a color code for the "Micamold" caps, I saw a thread where you said they were crap. I'm glad you verified this for me. The chassis is full of them. I imagine the ones that will go bad are the ones with B+ or high voltage on them like the video coupling caps. John told me about these as well(Are you Johnnysan?). Upon checking resistors I'm replacing these "Micamold" guys.

Jonathan

Yeah.. Hehe - those Micamold caps are just good ol' paper caps in sheep's clothing... er.. mica clothing. Actual mica capacitors are pretty reliable and don't normally need replacing unless they've actually failed. MicaMold caps are, despite the name, not mica. They're just paper caps in a misleading, molded casing.

Good luck with your recapping! Be sure to post some pictures of your progress too. We'd love to see how he's coming along!

-Ian

Well guys, last night I was just tired, and work on testing resistors until 3AM and went to bed. Today I replaced the 270pF micamold caps in the vertical section and a few others in that section. Only ones left I have to change are the 270pF micamolds in the video section and one in the audio section. There is also a 470pF micamold on the sync input terminal (What was this even used for anyway?), but I don't have a 470pF silver mica cap so it'll have to stay for now. I should be getting the 7 pin mini tube socket for the RF amp tube that I cracked, and hopefully get some more decent operation from everything.

I'm still wonderring about the scanlines on the screen. This is when there is no IF signal going into the video IF section since the RF amp tube socket is bad, all I see is verical and horizontal scanlines. I even see retrace lines too. I'm hoping after I finish recapping and testing more restistors that I'll get some progress.

RetroHacker,

Pictures will come very soon. Most free time I get I'm working on the TV. I'll take some pictures in the next few days. :)

Jonathan

Well, I replaced the tube socket. I turned it on and I immediately saw smoke and was greeted by the smell of burnt resistor. I never secured the socket to the chassis frame, so I will later tonight. I'll check for any shorts I never heard any sound, so there must definately be a short.

I've been pulling my hair out with this set... One problem after another, but that's what makes it fun. :)

Jonathan