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#16
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Yep. My nephew brought his truck by last Sunday, and two lug nuts were over torqued. My impact couldn't touch them and my old standby of using my cross bar and four pound dead blow hammer couldn't crack them. I told him to bring it to the tire shop who put the tires on and have them crack them loose.
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#17
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When I did my inner tierods I had to come up with something new....they have to come loose with an open ended wrench (the ends of my wrenches are not shaped right for the jack to grip at the angles available) my arms couldn't break the original 18 year old ones free...so laying on my back I managed to hold it on with my arm till I could get my foot on the wrench....then I used the greater muscle strength of my legs to get them loose. *That pipe usually lives in my suburban due to its lugs seeming to tighten themselves if left alone a few months. Torn muscles suck! Work smart not hard my friends.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 Last edited by Electronic M; 02-26-2020 at 04:25 PM. |
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#18
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Cool the table version , never saw another table model besides mine .
You will like the picture on this when you get it running , perhaps the best 16" I've ever seen |
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#19
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I installed the can this morning and the raster is now clean - and the bright and contrast controls work properly. I haven't seen a picture yet but the snow pattern is crisp Two more issues: horizontal running off freq and short vertical. Im trying to pace myself but it's hard to stay away! John |
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#20
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Progression from first plug in after 4 decades or so:
Had no HV. The main can filter decided to puke it's guts, so I restuffed it. Replace 10KV caps to get a "raster" of sorts: ![]() Found another can getting warm, so restuffed that. Found leaky paper cap in video amp overdriving CRT (no control over brightness). Changed three paper caps and 6S4 vertical output tube gave me more deflection, but not enough. Replaced bypass electro filters to get this: ![]() Connecting RF input and adjusting continuous Mallory inductuner to get to this point where the horiz is out of range: ![]() Found the horiz hold control was wide open in the middle of the range. Surprisingly, the osc still ran. Running some cleaner through it cleared the open spot in the control. A couple of paper caps in the horiz osc gets me here: ![]() Those lines are artifacts are from resizing the image. Vertical still short, so that's next. Once I get it right, I'll go ahead and do a full recap of all parts that haven't been changed. I've restuffed three cans so far, and will do the rest before putting the chassis back in the cabinet. Thrilled that the metal cone 16BP4 tube (that had a brightener on it when I found it) is strong. Very slight IF ring/smear as it's tuned, but I haven't touched any IF tubes. Despite that, has a very good picture. John Last edited by JohnCT; 02-29-2020 at 08:41 PM. |
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#21
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Normaly I just do all the caps , check resistors and tubes and then fire it up and see if there's more issues or just adjustments need to be made.
Your case is a slow replace this or that and fire it up , interesting way to do it but from what I see in the pics a full recapp and it probably will be good to go. |
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#22
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Ordinarily, I would indeed just recap the Andrea at this point now that the hard parts are verified to be working, but I wanted to use some tube troubleshooting skills that I last used (at least with television) in the 1970s or early 80s at the latest. If I was restoring this for a customer (I've done a few), I would have shotgunned it. But there is a big thrill in getting it going bit by bit. It was fun seeing the tube light in the first pic, then another thrill at each step, and I was smiling ear to ear when I got the first picture on it. So instead of shotgunning the old girl, I'm working through it. Once it's running 100%, I'll go ahead and restuff the remaining cans (I think there's four more cans) and replace the balance of paper caps. BTW, I like restuffing the cans because I hate adding terminal strips and external caps underneath the deck. If someone in another 70 years works on this TV again, the bottom layout will still look like the pictures in the Photofact. So it's not for originality, it's for keeping things neat and recognizable for the next guy. Hopefully, this TV will be running long after I'm gone (to the Carolinas hopefully ).Working on the various circuits instead of shotgunning is like building a model: I can't tell you how much I'm enjoying each step, and will be a bit sad when it's finally over. John Last edited by JohnCT; 03-01-2020 at 04:08 AM. |
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#23
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Update on Miss Andrea
Vertical sorted out. Video improved. I'm at the point where I know this TV will be a good performer, so I'm going to go ahead and replace the remaining paper caps and restuff the rest of the cans.
This is from a standard DVD of the Twilight Zone (Mr. Dingle the Strong) fed through a cheap modulator: ![]() I think the IFs are a bit out of alignment and my best equipment only does 45mhz. I have an old Precision 415 but I've never used it. Have to give this some more thought. John Last edited by JohnCT; 03-24-2020 at 06:25 AM. |
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#24
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I think that picture looks wonderful on that old crt. I'm inclined to believe the video IF is about perfect, can't tell on the sound from here. I applaud you for taking the time to keep your trouble shooting skills sharp. I too feel that's a big portion of the enjoyment of getting these going. Routine replacing of caps is rather boring after you've done few million.
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#25
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I haven't touched the sound section, but I suspect it will come around when I shotgun the rest of the caps and filters. Quote:
It's not a sickness, is it?? John |
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#26
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The distortion could be ratio detector adjustment. Definitely recap (and maybe check resistances) before playing with audio alignment. Early post WWII TV stations used stronger sound carriers so TV and sets were not designed to have the same sound IF gain as 50s sets....It may end up like my Stromberg Carlson Dumont RA-103 clone where TV sound is adaquate with volume at max and FM radio is far beyond adaquate at a lower setting. You got the affliction bad.... Just be glad it's TVs and not that other affliction going around.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 Last edited by Electronic M; 03-10-2020 at 08:58 AM. |
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#27
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If I'm not mistaken the sound is picked off just after the 1st video IF. If so there shouldn't be too much interaction with the video.
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#28
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Here's what's weird: when I put the TV/FM switch in the FM position, the screen of course goes dark but the TV sound gets considerably louder. I would be thrilled if the audio level was that loud when it's in the TV position. Note to those who are not familiar with this TV: the TV/FM function switch is NOT a bandswitch. This uses an infinitely variable Mallory "inductuner" (not a 12 position incremental type), so it tunes the FM continuously between VHF low and VHF high. The TV/FM switch does several things: it lowers the B+, it disables the sweep by ungrounding the 6CD6 cathode, and turns off the filaments to the video section and CRT. It looks like it's supposed to also ground the -11V source at the bottom of the main bypass caps but that doesn't seem to happen, but then there are also a couple of changes made in my version than the SAMS I have for it. All I did so far was disconnect the part of the switch that lowers B+ and the sound didn't improve, although the picture certainly deteriorated with the low B+. I don't see how it could be the shutdown of the filaments because the increase of sound is immediate when put in the FM mode, and decreases immediately when it's put back in TV mode. I'll play some more with it tomorrow. Kramden66 was certainly right: this TV has a very good picture, better than I hoped actually. ![]() The video IF definitely is a little off. When tuning from one extreme to the other, the picture is sharp on either side of center, but differently sharp (hard to describe it). One side has a bit of ring on vertical edges, the other a bit of noise. The center is free of artifacts but it has much less detail. I mean, it's very good, but not optimal. When I'm finished done recapping and verifying the resistors, I'll do an alignment. John Last edited by JohnCT; 04-05-2020 at 04:59 AM. |
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#29
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I have had 5 decades aligning these early sets with split sound like yours. The distortion cannot be just the ratio detector because the sound IF in a split sound set changes with the fine tuning. Remember it isn't an intercarrier sound set where the sound carrier beats with the video carrier to maintain sound over the video tuning range. In a split sound set you adjust for best sound and the picture should and must be set at that point optimally. The sound tunes like an FM radio and when tuned you accept the video as is. This is why you need the proper equipment to do the alignment.
You need a sweep generator and accurate marker oscillator to align the video and audio IF. There is lots of literature on this. Follow the manufacturers notes. I have aligned split sound Westinghouse, Dumont and RCA sets. (I currently have 4 pre-1950 RCA split sound sets). They all work superbly with full 4MHz video bandwidth and excellent sound. The alignment process is less forgiving but the picture quality is second to none when done right. And I prefer them as you do not get that intercarrier buzz! Remember that the video is transmitted vestigial sideband and so the video carrier must be at 50% down on the nyquist slope. The picture when tuned correctly will be sharpest not brightest. Seems to me you are almost there and hope to see you cross the finish line. Last edited by Penthode; 04-05-2020 at 01:07 AM. |
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#30
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In split sound sets there is interaction when fine tuning because the same front end local oscillator is responsible for the creation of the video if and sound if.
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