for Christmas I got an GE 7-818 F portable solid state am/fm radio that looks to be made in the 70s because it says solid state on it. I have zenith tube AM/FM radio and it still has all its original caps and it still works but I'm going to restore one day because it's a good radio. keep up the good work shango066 on fixing this well made radios/tvs. caps do fail but there not always the first to go.
As usual you've presented a great troubleshooting video. In my younger days I'd read servicing articles in magazines like Radio Electronics. Watching you go through every step, injecting signals here bias there and the like are even more interesting. Just seeing someone use the analyzer is neat too. Then I could never afford equipment like that. You have tenacity too, you simply do not give up. I used to have so much trouble with vertical oscillators that I find any oscillator troubleshooting video interesting.
Excellent video, Shang. I liked the way you used the signal generator to test for the bad oscillator. And I especially liked the cameo appearance by my idol Bob Martin, KE6YDO!
Just wanted to thank you for hundreds of very educational and entertaining videos :) I actually watch this quite often before sleeping, even my technical untalented girlfriend could now ressurect a deep desert TV... :)
28:05 The Song is 'Preisner - Farewell' As soon as NPR mentioned George Michael, I was waiting for you to say EOL ...And you didn't disappoint! The amount of celebrities that have died over here in England this year is unreal. Thank you for another entertaining repair video...I really enjoyed it!
In regards to the Christmas tunes...there's a line from the "Christmas Can Can" novelty song..."Heard this same song 20 times, and it's only Halloween". That tune "Last Christmas" and "All I want for Christmas is you" along with "Wonderful Christmastime" are played at least 100 times before Halloween. They may have been good songs at first but when they're repeated so often, it doesn't take long for them to get old. Nice radio too, your FM band there is packed full end to end!
Excellent video, great halfway break with the water scandal rip off. Love your faultfinding techniques and commentary. Keep up the great repair video's. That radio has great soundquality.
Fascinating. I would have thought maybe there was something wrong with a solder joint or a trace on the board. This really makes me want to build my own oscillator. I wonder if there are kits? It maybe a simple circuit, but is critical.
Nice job, as always. Btw, most modern low power transistors have very high dc current gain. This could be the reason why they don't work in that oscillator, the bias may be a bit too hard for them and the thing may need rebiasing in order to work properly. Also the parasitic collector capacitance may differ from the original, hence the odd behaviour and that running out of the frequency range. These things really are critical and a pain in the ass sometimes.
Transistor junction capacitance can effect those VHF oscillators. I wonder if GE selectively picked them for that part of the radio by BE or CB capacitance.
The comment at the beginning was hilarious. You're killing it with the comedy. Love all of your stuff man. Thanks for the entertainment and the knowledge. Peace.
I had one of those to fix years ago and it was the same thing. I know when you tune the radio and you get no stations as you did except for those 2 weak stations together that the oscillator isn't running.
Is the AFC circuit shorting out the oscillator bias supply? Try a 2n5179 in the oscillator. You can get them at Mouser or Digikey. Much better than that NTE crap.
what about a 100pf from the base of the LO transistor and GND also replacing the resistor that supplies the collector of the oscillator with a 138ohm resistor and a 1k resistor in the emitter should make that LO start-up instantly and work properly if not I don't know what else to try I am at a loss.
I love people.that don't give up on something,they stay at it tell they do ,nice repair ,I would love to no what transistors ,are good to keep around ,for stocking up on something ,to keep on hand some general ones that would be good to have around .anyone .
Can you do a bit more of a detailed video as to how these alignments work? How your scope and generators are hooked up and all that good stuff? These alignments still confuse me a bit.
Put a germanium transistor in it and see what it does. That seems to work for high frequency like you said I could work on in 108. I think you said with the Russian transit number that we tried in that time radio before we left the big mushroom
Tillmans videos would show the oscillator will stop if the bias is wrong. Replacing transistors you may have to use a pot to tune the bias resistance to start the oscillator of different transistors. Kinda like you do with capacitors in IF cans. Check out radiofun232 you tube channel. He is from the Netherlands.
Hi Shango You You Godless Capless Heathen LMFAO Ha Ha. That was priceless. I take Dave wasn't to thrilled with you. :) And I was beginning to think I had heard it all. Great video has always. All My best. Bobby
Has for my self I don't care what a person believes. To each his own. I have very little faith in most people, through the years I have seen the worst and very little of the best. And Doctors I hate ! has people are their victims. I have only met 3 that were human and tried to cure the sickness.
I'm new to your videos, but damned if this shit isn't right up my alley. Obligatory comment for your viewer engagement stats boost. Least I could do, especially considering RU-vid these days
sorry Shango066 the 2SC495 is a NPN transistor will work with a 1k resistor in the emitter and 27k an 12k should for the bias, the BFR96 is a pill type RF transistor
Ok cool, Im still trying to understand all the squealing from the pill I was using. I can understand if it was a converter and not a separate oscillator. I think the ticket would be a few trimmer resistor pots and dial it in but changing those values could effect the AFC performance
lol in first part of the video. im looking at that guy like " bruh. just about all my radios have the original caps and they all still work fine soo i dun give a fuuuuk.... then again there are a few that absolutely needs to be replaced some year.
ive got a issue that needs resolve. ive got this poratable f.m. radio whenever i turn it on as soon as the I.F. kicks in it starts motor boating like crazy with no volume response . the antenna is out on it but i plan to get that fixed . can you help?
Skaza no the 2N3904 did not work. He went through the alternative transistors rather quickly, but that one did not make the cut to the final 2 in the end. I'm still confused about which transistor of the finalists actually did get used.
you can get the situation where the PC board, through damp or whatever, goes so lossy that a VHF oscillator won't run. that circuit is very simple; the bc547 shown in the example circuit is very well known over here in the UK and it isn't even rated as a particularly high frequency device; only up to 150mhz I believe. So if that works, anything should!
I was thinking about that but dont really have an easy way to prove it except exchanging parts with the working board. That didnt indicate a the board was the issue
Hi. The critical value for an oscillator transistor is not only the frequency, but the junction capacitance, in the case of a Colpitts oscillator the collector-base capacitance is important, you should try to get a replacement transistor with cbc and ebc as close as the original as possible (frequency, mehh...). Nice vid, as usual.
the lesson not all caps in radios are the cause and fix the problem what I learned is you have to test all the circuits and trouble places and than fix what's wrong
Electronics can be like gambling .. it gets you because you have too much in it .. some stuff just can’t be fixed .. walk away, after 21 days, you’re free of it …
Caps? What? There are caps in these things? What......uh.....I don't get it. Uhhhhh, damn, I must have been getting it all wrong. I don't get the show. Your right, only the blind lead the crowd...but not necessarily the righteous. Where's the beef????
what the actual frick was that t the start? i know my comments can be long and broken english but what da hell was that at the start?! so no tv's that's fine just old radio's i like old radio's seeing as most 90's was either grey blockey or black blocky with slight hint of grey mostly on the front were the cr or cassette player went as pfff who buys "just a radio" in the 90's?
Why do some people like to fix old cars? Why do some people like to fix old houses? You can fix cars in the rain and you can fix houses in the rain, but fixing TVs in the rain is insane.
That's the reason I had to leave Antique Radio Forums. Purists go nuts if the power cord isn't replaced with an original brown color or anything else that makes them wet their depends. Way too much criticism
