Why Amateurs Should Not Service Expensive Antique Radios: 1930's Zenith Radio

Why Amateurs Should Not Service Expensive Antique Radios: 1930's Zenith Radio - 7S261

Рет қаралды 24,373

2 жыл бұрын

In this video, we learn what happens when a novice repair person works on an expensive radio to try and perform a restoration. While it is true, we must all start somewhere! A transformer set with very high voltages and expensive to replace parts is no place to learn the trade. I am really glad new folks are interested in learning electronics. But until one has worked on inexpensive sets, or been working with an experienced repair technician for a period of time, a set of this caliber should never be touched! Not only because of damage that could be done to a device from doggy workmanship (as in this case), but also because of the lethal potential of high voltages a transformer set produces. Playing around with 250 (and up) B+ voltages is extremely dangerous if you don't know what you are doing. You could literally kill yourself in the learning process! And until you are proficient at reading a schematic diagram, don't even try it! :(
Part 2: Speaker Field Coil Repair & Rewind - kzfaq.info/get/bejne/gJppiLKq0rXdYps.html
Part 3: Recap & Final Demo - kzfaq.info/get/bejne/Z8x4ZNSLm87PYJ8.html
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Пікірлер: 55

@vtjmproductionsusa2390 4 күн бұрын

LoL I have had to do a few reworks that the capacitor queens got lose on. So many think " recapping" fixes everything . Then when it does not work they always seem to find there way to my bench. Great video. 👍

@praha007 Ай бұрын

I'm an amateur and I have restored several radio's, tuners, tapedeck and a grundig 2355 tube radio, just for fun and hobby. So it is possible. The person you are talking about in the video was not an amateur, but an overestimating novice with no feeling for components and how to solder them correctly.

@fallenfirebird240 Жыл бұрын

As an amature who is actively reading up on electronics and referencing youtube videos, I don't understand how this could get so bad. I typically take it one component at a time and take tons of reference pictures before I do anything. It almost looks like they took a ton of components out at once and weren't sure where to start. Great video as always!

@rpcomms1 8 ай бұрын

Its called inexperience,and a little knowlege is a dangerous thing! Trust me Ive seen some right hotch potched two way radios RF repairs over the years make you shudder..lol So seeing this video as a engineer does not surprise me. Little common sense goes a long way too as shown with cutting and leaving danglers in mid air ether! Learn from other proffesionals is the best way,Yes take lots of photos which is so easier to do now,well done. Why Engineers used to get paid well for there skills and knowledge,sadly the repairs engineers are becoming a rare breed now and poorly paid for their skills in throw away electronics. Good luck learning more usual skills in your quest. Rob P 👍

@davem147 2 жыл бұрын

I have to rate you an "A" for your expertise, but a "Z" for your dizzying video!

@timlincoln2246 Жыл бұрын

I almost threw up. Twice. Tripods are a great invention for some. Case in point.

@knifeswitch5973 Жыл бұрын

Tripods are your friend

@ElectroRestore Жыл бұрын

Not really. You can't always get in tight spaces with them. Besides, my channel is free education. I can't afford expensive cameras and tripods and high tech editing software. Sorry! But I can provide valuable techniques and theory at no cost to the viewer. ;)

@chrisjarvis4449 Жыл бұрын

filmed in shaky vision

@mastdog Ай бұрын

I felt like the producer of the Blair With Project filmed this. I could not focus on what they were saying or point out because I got sea sick.

@Rebel9668 3 ай бұрын

Well, the only way you'll learn is to do it yourself. As you get better at it you can go back to earlier work and re-do it if it needs to be re-done. That is, assuming you own the radio and are doing it for yourself. There are still lots of things I'm unsure of, but that doesn't stop me from trying and learning. I've never had a set I've given more than $100.00 for and most were picked up for far less. The most expensive one I've had so far is a Transoceanic that I ended up giving to my uncle as a Christmas present. When you've grown up and live out in the sticks like I do there isn't much opportunity to work with a repair technician. My Pappy did work on electronics when I was a child, but I had absolutely no interest at all in the hobby back then...especially after he picked up a truckload of tubes and we had to spend days and days sorting them all back in about 1982. By 1989 all those tubes went to a landfill as with no internet or anything else at the time there was no way to gauge that they'd ever be worth anything in the future. Of course, hindsight is 20/20 and when I did finally gain an interest it was far too late for any equipment that my Pappy had once had so I basically started from scratch.

@ElectroRestore 3 ай бұрын

I really enjoyed hearing of your upbringing with electronics,. It brought back memories of my childhood being taught by my dad, who had a TV radio repair shop. I wish intensely, that more young folks were interested in learning to repair these devices! It is sad that not many have your zeal for learning it! The issues is not that they shouldn't do it till they learn how. It is the dangers of learning on a transformer set that sources out upwards of 600-700 volts AC ,and 200-300 volts DC to the plates of the tubes! One wrong touch, in the wrong way, and it's an all expense paid trip to harp land! Also, these devices are getting rarer to find that are not botch by bad service work. What I suggested was that folks learn on All American Five (AA5 and AA6) radios, which do not have high voltages, are cheaper and more plentiful, and easier to rework back to specs if a restore is badly done. You can stirp them to the chassis if needed, and try again, and learn much doing so! Safety first, skills second, expensive and rare device should be last. You have to learn to crawl, before you learn to walk, right?

@towerman75 Жыл бұрын

Zenith has always had a bad rep for circuit design, wiring, and poor documentation. When I worked as a bench tech in a well known repair shop, we had rules that we followed. If you messed up on something, your punishment was to work on all Zenith products that were already in the shop, or the ones that came in for one week. I always got stuck with their stereo's (which I hated).

@sypodj Жыл бұрын

Superb explanation thank you 👍 the way you bring it its very easy to understand 👍

@ElectroRestore Жыл бұрын

Thank you sir!

@butterbean4195 7 ай бұрын

hey paul good video. ill be in touch to come get my radio stuff.. stay safe

@jimmclay2353 Жыл бұрын

You really need to put your camera on a stand

@basspig 3 ай бұрын

It's a lot of extra work when the customer has installed Parts incorrectly or to the wrong connections because you have to trace point to point everything on the schematic to what's on the actual physical radio. It's a much more involved repair than just repairing something that failed what but was not touched by the customer.

@robertedwards3147 Жыл бұрын

I am a newbe and found that my radio to be a mess compared with this one so have removed all and starting from the schematic so far so good using tag strips so no hanging/lose parts thinking that this will be a good sounding radio and easy to service for th next guy.

@hotpuppy1 Жыл бұрын

Correct schematic is vital because you never know if it was messed with before. If it hasn't been touched, best to go one part at a time.

@jeanlawson9133 Жыл бұрын

How is it to become a professional if one is never an amateur...... AIN'T IT JUST AIN'T IT 😜 lols

@ElectroRestore Жыл бұрын

Ha! You got me! lol

@briankays2635 2 жыл бұрын

ER - THANK YOU! I'm currently working on recapping a Philco 37-61 that has exactly the same issues around the candohm resistor. The schematic is opposite the physical layout and someone got it wrong and it's not connected according to the schematic. I'm a novice for sure but I'm trying to learn and get it right. I spend multiple hours staring at the chassis and reading for every 1/2 hour of actual soldering and replacement. This video (especially the explanation re: smoothing capacitors at ~10:14) was just what I needed to see exactly when I needed to see it. Thank you for taking the time to propagate the knowledge and helping us all figure it out. Greatly appreciated!

@johnbravo7542 Ай бұрын

It makes it difficult when the camera is all over the place.

@mikepasko7493 2 жыл бұрын

I agree with you 100% I've been saying this for a long time.... that most of these so-called radio repairman on you tube or restores are complete butchers .... especially when they say oh it doesn't have to be exactly that value .... they're saying that they know more then the engineers/technicians back when the equipment was designed... I myself worked for Westinghouse in the 60s as a color TV analyzer fixing the sets that didn't pass the testing ..but a lot of these idiots on KZfaq just like to see themselves and hear themselves I believe and teaching the public everything that's incorrect ....I seen them Butcher up and destroy a lot of gorgeous radios and I tell them so also

@ElectroRestore 2 жыл бұрын

Agreed Mike, it is important to me to stay as close as possible to the original schematic, using the parts that are available today.

@andygozzo72 Жыл бұрын

actually in some cases resistance/capacitance values arent critical, valves/tubes are very 'unfussy', and vary in characteristic a fairly wide range themselves, anyway...

@jamesmann1243 Жыл бұрын

There isn't anything I despise more, than an egotistical uninformed Hack, who would argue with Karl Emde,( lead engineer for Zenith,) that they( the hack) knows more than any of the engineering departments of the major radio manufacturing companies that built excellent, reliable, and SAFE!! equipment that served the population for decades. Now, if its a matter of ignorance, inability to read a schematic, or just hyped up stupidity, hundreds, if not thousands of vintage radios and televisions have been permanently trashed to the point of a parts set, simply because one had no clue and business attempting to repair a unit they were in over their head in. I have seen it way too many times, and yes, the final outcome is usually cost prohibitive to the owner of a family heirloom.

@jeanlawson9133 Жыл бұрын

This is good stuff 😎 Thanks.....

@hav0k337 Ай бұрын

Thank you for this video. I've learned quite a few things. I wonder, if one wishes to restore such radio to working condition, and finding one of these old speakers is impossible (let alone rewinding the field coil), would it be possible to instead use a modern speaker with a permanent magnet, and any kind of inductive 1250 ohm load on the ripple smoothing side?

@ElectroRestore Ай бұрын

As long as the inductor can take the high voltage, yes! But I do have a video showing how I rewind a field coil. It really is not that hard. Actually, you can repair them if they are not too bad by replacing bad spots. If just the speaker is bad, you can put the field coil in the cabinet (if the original one is good). Assuming there is room of course. Then install a permanent magnet speaker.

@clifperry4677 Жыл бұрын

OMG, figure out how to keep the camera more steady, I m getting sea sick.

@johnhood3172 9 ай бұрын

Antique means 100 years old or older.

@a587g 2 жыл бұрын

Zenith was known for tying components together in mid air in their late 30's sets. Saved them a few pennies for a terminal strip. Not those filter caps though, someone should've used a terminal strip! I've seen a number of bad field coils in 1936-38 Zeniths. Usually what happens is the second filter cap shorts, and causes too much current to flow through the coil, burning it out. But it seems Zeniths are especially prone to this problem. It's possible the coil was already open before the previous repairman worked on it. They clearly didn't use the schematic, so I wouldn't put them past not testing the field coil before they started! I've also seen bad oscillator coils in these 1938 models, and of course the candohm is always unreliable.

@ElectroRestore 2 жыл бұрын

I agree that a person that would do such sloppy work would not think to test the FC for continuity before recapping. However, the filter cap was definitely in the wrong place, which indeed passed excessive current through the coil. The candohm resistor, amazingly, had no bad sections and was in acceptable tolerance for a voltage divider to handle the B+ current through the FC; had it been in series and dropping the voltage as required.

@murruti1967 Жыл бұрын

gracias por compartir tu expriencia. No sirve a las nuevas generaciones aprender de ellas.

@charlesharkin2165 Жыл бұрын

This is hard to watch pity

@badraven_indieauthor 11 ай бұрын

I agree, and YES we all have to start somewhere. I collect old radios, but restore cheap old radios. It is good to learn, but some things should be left to the experts. Especially, an expensive piece of history!

@Dogface1984 Ай бұрын

Any recommended inexpensive sets to practice on ??

@MrGigi-dz9cv Жыл бұрын

Condensers, don't 'convert' AC to DC. Rectifiers do.

@ElectroRestore Жыл бұрын

Rectifiers indeed do convert AC to DC by allowing current to flow in only one way. However, the DC they produce is fluctuating DC, also known as pulsating DC. It is not pure DC! It has an AC component to it. The only way to remove that AC (in a tube type circuit), is with a capacitor(s). Capacitors store charge like a battery, which is pure DC. Put an pulsating DC charge on it, and it dampens it via it's regulation properties. The only way to alter the DC voltage on a capacitor is by putting applying a greater DC charge, or a charge in the opposite direction. Therefore, they are the necessary components in true AC to DC rectification.

@MrGigi-dz9cv Жыл бұрын

@@ElectroRestore Maybe Pulsating current îs better.

@ElectroRestore Жыл бұрын

@@MrGigi-dz9cv No, Capacitors store voltage, not current. They store Electromotive Force (EMF) in the form of a charge (like a battery). The E is why Ohms law is not V=IR. But rather E=IR (or I=E/R or R=E/I).

@meesterprofe007 8 ай бұрын

Camera work needs refining

@billysharp3388 Жыл бұрын

Well are you going to do it right by checking each capacitor on a xy scope and make sure you put each capacitor in the right way? I am not talking about filter caps either they are marked others aren’t and if you don’t put them in right they will cause noise. Not a good idea to talk down hams!👎.

@ElectroRestore Жыл бұрын

Always do! :)

@hestheMaster 2 жыл бұрын

Unfortunately novice radio repairmen never consult a proper schematic, nor do they take notes, nor do they understand what they are looking at compared to the schematic. They also have components sometimes just hanging in the breeze. When going over a previously touched radio you have to check everything the last person did AND the existing wiring and components. Basically double the work for a restoration .😒

@ElectroRestore 2 жыл бұрын

Exactly! Twice the work and diagnosis time! The good side, if there is one, I guess would be the radio should end up even better after the detailed analysis and painstaking repairs.

@andygozzo72 Жыл бұрын

you cant always blindly trust even official schematics, there may have been changes during the production of the set which wouldnt be in an original issue service sheet, or vice versa, you may have an early set, but schematic for a later one, and this isnt always stated... even more variations likely in any set produced during wartime due to component availability problems....it may also have been modified for various reasons, maybe due to not being able to get correct parts, so altered to suit others

@vancouverman4313 6 ай бұрын

Unfortunately, Mr. Carlson and yourself dont take on many apprentices, so people are forced to learn by trial and error.

@ElectroRestore 6 ай бұрын

Trust me, I sure have tried to find some young folks that would want to learn in my area. If we cannot pass this knowledge on, it is just a matter of time that these radios will be tossed to the landfills because no one will be able to service them. I mean us old timers are dying off. I am kind of a youngster in the field at age 64. I don't get to make as many videos as I'd like. Due to the declining number of techs, my work load is quite extended. I am not a hobbyist but actually run a restore business. Maybe by time I retire, I'll find someone that has an aptitude and desire to learn vintage electronics. :)