Transistor Radio Repair: Logical Fault Finding
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- čas přidán 26. 07. 2024
- Ever wondered how to start to fix a radio? If you follow the basic steps you should be able to narrow down the fault fairly quickly and easily with a bare minimum of test equipment Logical fault finding is a useful skill to develop so you can work more efficiently and not do work that doesn't actually need doing. Transistor radio repair is very satisfying as a hobby but you can end up chasing your tale if you just approach things in a haphazard manner. A transistor radio circuit diagram may look like a real jumble of lines and symbols but once you get the hang of it you can follow the lines and match them to points inside the actual radio.
I only use basic tools, most notably a signal tracer which you can buy ready made, build from kit or even from scratch. Other tools are a power supply, audio generator, and some basic hand tools.
This particular video is me using a Hacker Herald RP30 radio which was bought from eBay as spares or repair. Taking into account all of the parts used the repair cost less than £3 and around an hour and a half on video. Without filming it would have been quicker. A novice will take longer but the more you do, the better at fault finding and repair you become.
The links mentioned in the video are below for the signal tracers.
AllTheGearNoIdea : • K7000 Velleman Signal ...
BD Electronics Kits: • DERB - The BDST-1 - Hi... - Věda a technologie
Well done George. I love the descriptions on Ebay as to condition. It's even better at the Ham swap meets when you ask the seller if the radio works. He says, "It worked the last time I used it." What he neglects to tell you is the reason that he stopped using it. Namely that it went on fire the last time he used it and it's never been used again. 73 Doug.
That's the rub isn't it. Why did they really put it away. On broadcast sets it could be the lack of FM but probably not, more likely it was too expensive to throw away but cheaper to buy new than repair the old one.
...speaking for MYSELF- I actually look for transistor radios that don't work, because I know how to FIX them-(!)
One of the best videos on a logical path to fault finding I've ever seen, thanks George. Would say that the AGC on that probe would drive me nuts - but then, so does constantly having to reach for the volume control on a manual one.
George this a super video George I really
Enjoyed this .has given some confidence to try fix one with not much tools
Nicely done George. Logical fault finding can be highly illogical at times, but in the main, it's the sequence you show here in your video.
A basic test equipment setup is all that is needed, nothing flashy, and needn't be expensive.
As you know, I have also started exclusively using different transistors, more commonly available than those that are the norm, and to great effect.
Nice nod at the end there to Chris' latest video - did make me chuckle 😁
You know me, sense of humour with an irreverent streak. It's mostly common sense but logical makes life easy!
I've said it before and I'll say it again, you have a lot nicer old radios on that side of the pond! Great teaching video!
Many thanks Bob. Some are nicer but you had better designs on your tube sets than just brown boxes.
Loved the editing on the finger motion mate 😂
Another great video and greatly appreciated. As a newbie to this sort of thing, this very basic tuition is learning gold to me. I really appreciate it.
Glad you enjoyed it, Really should do more basics videos really because I think they will appeal to more people starting out, not just the old hands redoing the same thing over and over.
@@GeorgeChristofi That would be a good idea...otherwise you are preaching to the converted! Whereas there are lot of people who are interested but may lack confidence to ask in case they look stupid.
I'm a photographer by trade and from teaching, I know what is obvious to people who have been in the trade for years, is a big hurdle to newcomers.
Little things like which wires from the Hacker's battery leads to connect to with a power supply. Obvious to you, learning gold to me!
Nice step by step debugging and repair George!
Thanks Tony. Logical fixing is better than blind luck!
Hi George, like the direct strait forward diagnosis. Thanks for the stream , entertaining!
Tried to do a straightforward, no faff run through of how to see whats faulty. Us old hands can sort of do it in our sleep but newcomers might just take one look at the insides and give up. Thanks for watching it Keith. All the best.
Rohde & Schwarz? Name dropper! Cheers George, nice wireless. None of that Roberts crap.
Had to name drop, just in case people were unsure who makes decent test gear! Almost as much fun as repeating current limited power supply!
Great instructional video George and nice bit of fault finding. The usual suspects again. Nice use of silicon without re-biasing though. Signal tracer was interesting as not seen one of those before. Cheers Graham
Glad you enjoyed it, Just thought I'd go back to scratch. The signal tracer is the same as Pauls one, the ELV Bausatz Mini-Signalverfolger MSV1. Unfortunately, since brexit they don't ship to the UK any more. Take care, All the best!
That was a great troubleshooting video on that radio George, I didn't know that a simple change out of the germanium transistors with silicone transistors would work without a change of biasing.
Hi Jim. I think both Roberts and Hacker radios have such broad tolerances on the transistors that pretty much anything will fit. The ideal is low noise higher amplification devices and you just have to match that with voltage ratings of the devices. I could have fitted Russian germanium but I'm hanging onto them for now because the guitar crowd love them in effects pedals.
Great video George! Very systematic troubleshooting technique and great results. Thanks for a great video!
Many thanks Gregg. I see so many people just assume what a fault is without actually testing properly.
This video really helped me on my transistor repair 👍👅
Hi George! Good to see another video…..not sure you have noticed or not, but sometimes those “paint” dots are actually spider poop….For years I thought that every radio was near someone painting until I noticed that there were those spots beneath long lived spider webs. Great tips on testing…..love the term “jiggery pokery” Thanks for sharing…Take Care-Larry
I hadn't noticed that and spider poop makes sense. That radio new would have been nearly £30 which then was pretty much 2 whole months wages before tax so having it in a room where you were slapping paint around would not have made sense. Think I'm going to do a few more basics type videos to help newcomers in the fixing game rather than just teach old hands to suck eggs! Nothing like a bit of jiggery pokery to make it work! all the best Larry, take care.
This video came just in time beacuse i got a old radio and the switches got bad contacts and now it works, ill try fixing another one too thanks.
It is a great hobby to get into. It can throw curveballs at you for obsure faults but generally once you get to find your way around you will find it interesting and fun.
very nicely done George nice track repair I usually save all my LED legs for making links and track repairs
I just use whatever is lying around on the bench... There is always something and in the event I have actually cleared up, I have rolls of tinned copper wire for the job!
@@GeorgeChristofi so Have I.
I even have a full Roll of tinned copper wire I got from maplins still unused !
I never saw one of those Hacker radios over here in the states. The other one they fail to tell you in the EBAY description is that the power supply was removed from the radio. Rubbish capacitors and non functional transistors always a good rule of thumb and yes I do have a thumb that is one inch shorter than the other. Yes all very good practical steps to diagnose a radio George. There are illogical ways but those normally produce sparks and magic smoke. Thanks for sharing George always a pleasure.
Many thanks Larry. If you do see one in the US then grab it because there was only ever one export model. There are very few of them left at all! With a lot of British sets, they use the AFxxx series of transistor and they are prone to growing whiskers internally that short the can to the junction. It's a good idea to tap them and you can get the radio back to life. Also, capacitors... Certain brands are change on sight these days. Neither of those will diagnose a blown speaker or faulty power switch!
This was the perfect video for the beginner. Brilliant. 👍😊
Glad you liked it.
Great video as always George. I like your description of the typical ebay listings. Those band switches are definitely one of the very common failures. Best regards Chris
Thanks for the channel plug. Regards Chris
If it isn't band switches or volume pots its got to be caps and af11x series transitaters
@@allthegearnoidea6752 No problem!
As a novice I have learned loads thanks for you great production.
A great instructional video, George...sooper-dooper.
Thanks. I thought it needed a no faff radio fix video to show how easy they are to diagnose and repair.
Nice job on tracing out the radio George.
Many thanks Bill. Hope you are feeling better now.
Hi George, great vid.
Thank you for learning
Thanks!
Very nice video. I am fixing a Philips Jenny de Luxe 250 90RL250/22R.
Good luck sir 🎉
Great video George. I've a dead (lights up) roberts rp60. Would you have a video on those? Cheers, ken
Excellent video. I have a substantial collection of transistor radios from the late 50's to the present day.
Quite a number of the Roberts have failed AF117's and I have tried a number of fixes e.g. cutting the shield wires or zapping with 50v. I wonder if you would be so kind as to recommend the suitable silicon transistors that you use. I am an electronic hobbyist but lack the experience to choose a suitable silicon replacement. Thanks and keep on giving helpful advice!
What silicon transistors did you use for replacing the germanium ones? Thank you of good informative video.
Great Video For People Who Are Just Starting Out At Trying To Repair These Old Radios George And Very Clear And Informative George Wonder Were You Can Buy Bobs Signal Tracer Kit I See You Did Not Put Any Of The GT322Bs in It But What Silicon Transistors Did You Use With Out Altering The Bias ? Yep !! Nice Eduactional Video George Regards mike.
I just tried some old if PNP transistors that I had lying around and they worked fine. As for Bob's kit, there should be a link to the video and the website description is in Doug's description.
A lot of Germanium Transistors will have to be replaced with Silicon as the Russian Transistors are not available now, Good Video. See you at Golborne I hope.
I'm hoping to be there Steve, see you before you start your new life.
Where did you bought the probe?
Hello George nice work on the hacker where can I get the signal tracer thanks JOE
That tracer is an ELV MSV1 which you can get from amazon or ELV direct but only if you are not in the UK. Since Brexit ELV will not ship to UK or Northern Ireland.
@@GeorgeChristofi thanks for your quick reply George in your opinion is the msv1 a good signal tracer where do you get your capacitor from that you use on the hacker radios thanks Joe I live Canada
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@@joeramanno7742 I really think the MSV1 is possibly the best tracer I have. Having both a signal level meter and an agc circuit means you can just use it and hear the signal without having to play with the volume control. My capacitors usually come from Farnell which is part of the Element 14 group. I can buy cheaper from China but the shipping time can be a problem. I usually buy 200+ of each value to bring the costs down.
Would you know why the volume would just go straight from low to high on its own on my radio.
That normally is a faulty volume pot that would cause that fault.
Does "destructive testing" 07:13 involve the use of a hammer and why was an adjustable wrench used instead of that?
Please elaborate.
The adjustable wrench was the closest thing to hand. The idea is to break any whiskers of tin that have grown inside the transistor can shorting the junctions to ground.
@@GeorgeChristofi I discovered that you can use an electric toothbrush or vibrator to shake off the whiskers. It seems to do a better job than tapping.
I do have a chinese made 'facial massager' which I have tried but with little success. These days I find it easier to put low noise silicon transistors in them instead and dump the germaniums.@@Christophers-Assorted-Stuff
20:48...it might be a good idea to bridge the trace(s) running parallel to the trace you are fixing-(!)
Bloody AF117s.
Yep, Blooming rubbish they are!
Can you really just put Silicone transistors into a radio like this without panicking over bias arrangements etc??
Sent radio to radiocruncher. He will reair radio with correct test stuff.
I have better test gear than radiocruncher. I can also work faster!
Strange T shirt. Reading is fun with a pentangle?
Its a play using old nick himself reading one of his books. I guess reading is good, regardless of the author or the subject!
The radio sounds terrible, I don't think it's working properly, after you say it's fixed, noisy with poor reception.
As I say in my videos, the workshop is pretty much a faraday cage here so all of the electricals that are in the room during filming pretty much wipe out any signals that do get through the sheilding. There is only a local AM transmitter which shut down a few months ago now and the FM transmitter relay for one national independent that gets through the walls here.
Lose the PINK Hair man !
It's ok, it's been various colours since then. Currently blue