FNR - Motorola VT-71

[@bandersentv]

I spent about 8 hours working on the set. Yes, I do a lot of retakes and probably toss about 2/3 of all the video I shoot. I've mentioned my background a few times in various videos. Basically, I have a degree in electrical engineering but make a living as a programmer. I like to fool around with vintage electronics both because of the engineering angle but also I like the cabinet designs.

[@bandersentv]

Thanks. Yeah not so many restorers around, but there is a need. Even though I have way too many of my own projects, I've agreed to restore some cool sets for other guys. You'll be seeing one of them soon.

[@WB8MHE]

As usual, FINE JOB!!!. As to the poor soldering of connections, I'm 82 y/o, & well remember the tools we had available in the late '40s & early "50s. We had 1/2" diameter roofing soldering irons & 100 watt soldering guns, with solid #14 copper wire for a heating element, if we were lucky. We did the best we could, but big tools were a limiting factor. My first soldering pencil in '47 was my childhood wood burning pencil from Gilbert Toy MFG. Worked great. Keep up the good work. Dick

[@bandersentv]

Oh yeah. I remember watching some of those videos a couple years ago and had forgotten.

[@OldRadioAl]

I'm jealous of the new Sencore. That's one nice and handy unit. Another good, informative video.

[@albertmorris4889]

Hi Bob. I suspect your mystery clipped caps was a troubleshooting step. At one time it was common practice that a "suspect" component lead was cut to test then if good a tack solder repair of the lead.was done. Quick and DIRTY method but it did work (at least long enough to get it off the bench). Good job as usual.

[@bandersentv]

I added a link to the description. It only works for some electrostatic sets.

[@bandersentv]

Yep, that was meant as a little blooper bonus for anyone that made it to the end :)

[@PaulHigginbothamSr]

I can see a guy restoring this set in 75 years. He complains bitterly that he has to vaporize the solder off the terminals because the laser heating doesn't see into the cap well enough to read its internals. And that completely missing cap? The set probably worked fine back in the day and is now jittery even with it. That probably has to do with the missing em covers though.

[@thomashowe855]

“Oh no, it appears my holorepair station has broken down”

[@lookoutleo]

you realy are a proper tv repair man, i learned on transistor tvs in the 80's but mostly forgotten now , never did much on valve tvs, interesting video

[@bandersentv]

Thanks! This was fun project. I have a bunch more of these Motorola sets to get to. Maybe I'll set up a little assembly line :)

[@lookoutleo]

i'll watch your videos as i fancy getting an old valve tv and repairing it. your videos will be invaluable :) can i ask you questions if i find one?

[@bandersentv]

I think you'll be better off joining a vintage TV forum like the 'Antique Radio Forum' and asking your questions there. Together the forum members have far more experience than I.

[@bandersentv]

Yes, there's a piece above the ballast tube to protect the cabinet. All the Motorola 7" and 8" sets have it.

[@AntiqueRadioandTV]

Hey Bob: I loved that video! It's going to be great to see you do an alignment & try out some mods in the next video. Yes, I'm slowly getting there with mine as well when I have the time to work on it that is. It's coming out great. Isn't that PR57 terrific! It's funny. I've got the same chassis, DVM, & PR57 right in front of me. Looks like I'm there at your place! I love the outtakes at the end! Oh, yeah... Been there, done that!!!

[@foxrivers]

Someday I'll finish my VT-71. I've had it for 10 years and recently replaced some caps and built one of those capacitor ballasts noted on VK. Great audio but no raster so I put it away for now. Once I move into my condo and get a workbench set up I may tackle it again.

[@OlegKostoglatov]

There is an outfit called Steele Rubber products that specializes in reproducing rubber parts like weatherstripping and tailight gaskets for cars. Supposedly they can make parts to order so it may be worth asking them about the Motorola VT71 gaskets.

[@bandersentv]

I crunched the numbers and came up with a couple designs. I'll demonstrate them in the next video.

[@bandersentv]

I've never noticed so I'd have to say no. How much does the image shift in your CRT clock ?

[@bandersentv]

HI. Wow, I can only imagine how difficult it must have been with a huge iron or gun. I had enough trouble with my little Weller iron!

[@bandersentv]

Electrolytics capacitors age from just sitting around so they all need to be reformed to some extent if they have been used for a long time. How well they reform depends on the condition of the electrolyte which breaks down and dries out over time.

[@bandersentv]

I think you might be confusing the diagonal retrace lines with the dots and dashes at the top of the screen used for closed caption info.

[@bandersentv]

Thanks, glad you enjoyed it. You'll see all that stuff in the next video :)

[@AntonBabiy]

Hey Bob, it would be cool to see the retrace, and dc restoration circuits done with some re-stuffed caps cause the old ones look REAL COOL :D

[@MrKevinp0]

Very nicely done as always! Love the "bloopers" at the end. Maybe when you release your DVD collection of your greatest restorations, you can include more bloopers in your special features section. LOL Just kidding of course! I, like so many of us, are appreciative that you share your hobby with all of us, and eagerly anticipate your next video! Have a great day! :)

[@thomashowe855]

I’d love to see that happen, though.

[@bandersentv]

Thanks. It's a transformer used in the horizontal oscillator.

[@GeoN0JRJ]

Another great video. I have been working on my Motorola little by little as work allows. This will really help! I would really like to see the MODS and Ballast testing if you get a chance Bob. I learn more every time I watch one of your videos.

[@eivindamundsen7090]

Tanks for a great video. Btw Where do you buy the 6KV capacittor ? Why haven't I seen your channel/videos before now ?

[@bandersentv]

You're welcome. Allied Electronics, Mouser and Just Radios have them

[@bandersentv]

I didn't posses a sweep generator back when I restored my other VT71s.

[@ct6502-c7w]

I'm considering buying a small antique tv I found online, and I think it's this model in your video. I have some experience fixing vacuum tube radios, and a couple of years ago I also restored a 1952 Olympic tv. It was the first time I had ever fixed a tv, but it's still working great! I know this video is several years old now, can you think of any other advice if I do decide to get that tv I saw?

[@bandersentv]

Watch some of my other videos on this model. Also join the Antique Radio Forum and post about your project in the Television area. Also read some of the VT71 restoration project threads there and on Videokarma. Also check out Phil Nelson's excellent website. www.antiqueradio.org/motvt73.htm

[@NBH45304]

Great job once again. Is that a bias cell above the high voltage capacitors ? I have an old Emerson radio the has a L49 ballast tube in it. I have never messed with it to see if it's any good. LOL at the end so disgusted you had to stop the camera !

[@TechneMoira]

Hey Bob. I'd like to ask if you could make a drawing of that flyback line suppressing circuit and where to hook it up (maybe mentioning how to calculate the parts specs ?). I suppose it's a fairly universal circuit, meaning, it could be inserted into basically any tv set? Thanks a lot. Vincent

[@Mikek2bn]

Bob what value power resistor are you using to replace the 7jp4 filament???

[@bandersentv]

Michael Tannenbaum It's a 6.3 volt filament with 0.6 amps so applying ohms law gives 10 ohms at about 3.6 watts. I suggest using a 5 watt or bigger.

[@Tysman909]

How would I build those rectifiers for my tuner they have like 3 of them. I can email you the schematic or look it up its a Harman Kardon T250 Ode

[@bandersentv]

You mean selenium rectifiers? Replace them with silicon diodes. I use 1N5408s

[@Tysman909]

@@bandersentv ok will 1n4007 work with dropping resistors and how would I wire them up? I can email a schematic or I can find a link to schematic for you

[@bandersentv]

I don't bother adding dropping resistors. Some do some don't. I don't think it makes much difference. If you do use them they simply go in series with the diode. Wire the diodes in the same way as the selenium. You're just replacing one diode type with another.

[@bandersentv]

BTW I'm not trying to be difficult. I want you to learn. Do some research. Why would you add a dropping resistor ? What's the difference between selenium and silicon ?

[@Tysman909]

@@bandersentv thanks I do wanna learn just don't wanna wire them up wrong cause there's 4 of them in the tuner. The matching amp a technician already replaced the rectifier with 4 modern diodes and large 3 watt resistor

[@mjdmtlakes]

Thanks for making such a long and in-depth video. I am curious, for almost an hour of video, how much real time elapsed? Also, enjoyed the failed takes and wonder if those kind of retakes are normal in making your videos or if you are able to assemble the final video from one take? Please consider doing a biographical video. I would love to know more of how you got started with this hobby and how you live with all of these antique sets in your daily life.

[@bandersentv]

Wow, I didn't think the earth's magnetic field would affect it anywhere near that much. I bet a mu metal shield would help a lot.

[@ct6502-c7w]

Hi, I ended up buying one of these same model tvs, and I'm hoping you might be able to help with something! (I'm sorry this is a long comment). My tv has a TS-4H chassis. I replaced the main electrolytic capacitors (C1-C3, in the cans). I was using the "Sam's Photofacts" schematics I found online. It was really confusing because there had apparently been some changes evisions that didn't match up with the diagrams. But I found a Rider's diagram and I was slowly able to make sense of things by comparing the two. Last night, I tried to power up the tv for a quick test. The vacuum tubes glowed and the ballast tube got warm and seemed to be working. But after a few seconds, I saw smoke and I realized resistor R87 had burned up. It's connected on pins 8 and 6 of tube V14, which is the 25L6GT tube next to the high voltage box. (It looks they are using pin 6 as a tie point). The problem is I have no idea what would have caused the resistor to burn. That was the only thing that burned, I didn't see any other burned resistors or other damaged parts. The area I worked on seemed to be okay - the electrolytic caps and rectifiers didn't smoke or do anything else strange. So at least I THINK I connected the capacitors on right! But I'm stuck now. Do you have any suggestions on what might have caused the resistor to burn? There are a couple of wax capacitors connected to V14, and I think a high voltage one does too. Is it possible one of the caps could be bad and is causing a short? I'm really hoping you can help since you're the only person I've seen who actually has experience working on this tv. I posted a question on the Antique Radio Forum, but I don't think that many people there are familiar with this particular tv.

[@bandersentv]

Hi. Yes, I've seen your posts on ARF. I'll reply when I get a chance. Forget about the Sams - it's for the TS-4J revision.

[@ct6502-c7w]

@@bandersentv Thanks! I saw your reply in that thread. If you have time, I had a couple of other questions, which I posted there.

[@PaulHigginbothamSr]

Glassinger Ron always just lays the lead against the side with no wrapping and since he uses such a massive soldering iron with lots of practice he has a collection that works just fine that I would not mind owning a unit out of.

[@bandersentv]

Maybe. I've never work with anything like that before so I'd have to do some research.

[@laurdy]

you might be able to mould some new crt masks from a good old one using silicone rubber

[@bandersentv]

I love it and should have gotten one a long time ago instead of the iso-tap and cheap variac.

[@bandersentv]

I know, not much I can do about it now :(

[@gbowne1]

never done an alignment on a VT71? gee.. i figured by now you would have.

[@MrMac5150]

can all caps even newer one be reformed.

[@td3993]

Can't taste the smell of a selenium rectifier failure through KZbin.

[@laurdy]

the user brickintheyard has some good tutorials on mould making using silicone and other materials

[@larryparrish4738]

I just got a 1949 7vt5 and a similar 9vt5 am going for it help

[@mariaclaraganam4946]

Estou precisando fazer um trabalho sobre essa tá alguém sabe me dizer tamanho e medidas dela

[@mattswestone20]

does this set contain asbestos?

[@entity9742]

Some sets had capacitors or protective tube coverings made from asbestos

[@bandersentv]

I would if it paid anywhere near as well.

[@MrMac5150]

The fan air is coming right into your mic.

[@antiquetaperecorderlovermu9699]

Super super super 😮😮😮😮

[@chairuser4]

so mad you cant get the surround anymore,could you learn to make one,like expanding spray foam an a form,must be a way.

[@AntonBabiy]

tape some foam onto the mic. Just saying for another vid. Cancels out most of the air noise :)

[@cny02253]

Seems like the most unpleasant part of the restoration process was explaining the most unpleasant part of the restoration process. lol!

[@renatoscutube]

That was so, so unpleasant you couldn't even talk about ... lol