#197

[@TheRadioShop]

Great fix peter. I always love the way you take the time to explain things. Thanks for sharing my friend and 73

[@TRXLab]

Thanks Buddy for your words always very much appreciated! Thanks for stepping by my friend! 73

[@Budro4764]

Did you build that RX meter he showed in a video ?? I got the info but can't decipher his writing on the schematic....

[@mikesradiorepair]

Nice repair Peter. A fairly common problem with CB radios. They have such a poor front end protection circuit (just two diodes back to back) that it's not uncommon to find the first RF amp blown. Amateur radios tend to have a much better design for front end protection and frequently include a gas discharge tube.

[@TRXLab]

Yeah that is right Mike all have to be build on a budget these days and I'm scarred when I see what we get from China. The change to fix those radios are very little as we don't get service manuals not even a simple schematic and you don't get parts either. But the radios are cheap and will help the keep our environment clean :-(. That is truly sustainable isn't it?

[@jbuloke]

I'm New To Your Channel And Love Everything about This Video. Excellent Video And Highly Educational. I Greatly Appreciated The Way You Explain EveryThing And On How You Go By The Book And Do Things Correctly And Not Take Any Shortcuts. Also Greatly Appreciated On How The Meter Comes into Play With The Receive Issue. You My Friend is A Great Excellent Technician. 73's My Friend and Waving the Hand From Gambling Capital Of The World Las Vegas Nevada.

[@TRXLab]

Thanks glad that you like my videos..and thanks for feed back 73

[@RevGunn-jq3cq]

I am constantly amazed by your knowledge and skill. It was a pleasure watching!

[@TRXLab]

Thanks or the kind words. 73

[@iw0hex]

Great repair Peter, thanks for having shared this video. 73s my dear friend from Pasquale IW0HEX

[@TRXLab]

Thanks my friend all the best to Rome!

[@Perspectologist]

Thanks for sharing this with us. I recently discovered your channel and I really enjoy what you do. Each repair video is like a detective mystery and I am excited to follow along. I presently have a software background, but I am becoming inspired to get more into hardware. Thanks for sharing your experience with us.

[@TRXLab]

Thanks for feed back. I'm glad that you like my videos. Thanks for comment

[@user-uv4xe3cq2y]

Very good video! Especially a good touch to test the old component vs a new one for comparison. Keep up the good work!

[@TRXLab]

Thanks Theodore 73

[@hawke2325]

I've never liked the E-Paper display on the Rhode & Schwarz but the more I watch your channel the more I am getting to appreciate its uncluttered display. Cheers Peter 73's

[@TRXLab]

I really like the CMS display over the CMT or Schlumberger versions as it is clear structured and as you already said uncluttered which gives you a good overview over all needed parameters at once. 73

[@OleF112]

Hi Peter. I love the CB chapter, it was about time ;-) Someday i will push you to the commercial radio section, and then all comes down to a perfect end;-) Just kidding... Excellent trace for fault at just the right point to start! First guess was a hit. Another old CB back in service instead of buying a cheap chinese new one. Thank you for your work and sharing here one YT. 73 de Olaf!

[@TRXLab]

LOL yeah no problem Olaf just push me to have mission accomplished haha. And you are right buying cheap China products will cause an environmental issue. We can't fix those radios as we don't get service manuals nor parts but we get more harmful electronic waste. That is not sustainable we all should refuse buying those products as long we don't get proper documentation! Have a nice Sunday!

[@alancordwell9759]

Strange about the audio distortion, I was expecting that to turn out to be the IF filter! Great repair as always Peter :)

[@TRXLab]

Hi Alan, ah you think about the Toko crackling issue? Well not sure if I have seen a Toko producing this kind of distortion. Faulty Tokos always had a different behaviour. Thanks for stepping in

[@DerekHerbst747]

Hi Peter. I believe the biggest cause of gain loss on transistors is from reverse voltage. Most probably the CB Radio was incorrectly powered at some point. Ich hab dich vor kurzem abonniert und genieße dein Videos. Danke!

[@stargazer7644]

Front end transistors generally die due to static discharge to the antenna, or too much signal. Another transmitter antenna too close, or trying to switch two transmitters into one antenna with an antenna switch without enough isolation. They have very little protection.

[@martindowney7915]

Cool work Peter, great explanation, great video, thank you 73.

[@TRXLab]

Thank you Martin 73

[@bundylovess]

Good repair and nice video peter big thumbs up 👍

[@TRXLab]

Thank you Allan. 73

[@ivanivanych5959]

Great job, herr Peter! I think, the reason of transistor damage is some strong static discharge. Maybe the radio has been used at rainy day with lightning. Couple of times in my practice i faced the situations, when the 1st stage RF amplifier transistors have been damaged, but the tester found them OK, because it perform the transistor test with DC. So, i was a bit confused.:))) But, in your case, the transistor was damaged completely. Good luck!

[@TRXLab]

Yes Ivan I do believe the same a kind of static discharge. Thanks for watching 73

[@PileOfEmptyTapes]

So it was a fairly straightforward fix after all. Poor transistor acts like a Zener C-E. I hope you took the time to replace the dead lightbulb in the LCD backlight as well (or at least I assume that's what's causing the uneven brightness - it was quite common in the late '80s, presumably being cheaper than LEDs). Aber mal ganz ehrlich, bei dem Englisch kriege ich regelmäßig die Vollkrise. _Aua._ Ja, ich weiß, da wird sich wahrscheinlich nicht mehr viel tun, also bin ich jetzt auch mal wieder still.

[@TRXLab]

Yes you are right it was a straightforward fix not to difficult but still exciting with the funny distortion. Naja Du hast schon recht viel besser wird es wohl nicht mehr. Wenn ich einen Deutsch- Muttersprachler Englisch sprechen höre, kann ich das auch sehr oft nicht ertragen. Vielleicht mögen wir unseren eigenen Akzent nicht. Auf YT Englisch zu sprechen is Bürde und Chance gleichermaßen.

[@gamlemann53]

Maybe it has been some static voltages from the antenna who has taken the transistor out? Nice video Peter! The best from LB1NH Arild from Oslo Norway :-)

[@TRXLab]

Yeah Arild that is what I do believe too... Thanks for watching ..73

[@Budro4764]

I am curious if you did a voltage check on that transistor also ??? Some Sam's manuals and service manuals will give you a voltage chart for each one .......

[@rayfalcone6897]

another great video,Peter,thank you for sharing.....

[@TRXLab]

Thanks Ray!

[@TheDefpom]

I have seen so many blown first stage transistors or shorted diodes in radios, so common, especially from radios used by truckers where they may sit side by side in a parking lot or at a loading yard, front end overloaded. I also didn't like how long the legs were left on that transistor from factory.

[@TRXLab]

Yeah you are right Scott. Thanks for stepping in

[@gvvq-pi5ml]

Nice video Peter, i like the transistor tester from Fred g4vvq

[@TRXLab]

Thanks Fred. Yes the tester a a useful little device.

[@MrKelendros]

Hi Peter, great repair!! I'm happy you put cb radio videos again, it's my hobby (one old president grant waiting for me for funny repair try) the pen for injecting signal is as simple as one cap for protecting signal generator from dc or have something else? Thx a lot for sharing your time putting those videos

[@TRXLab]

Thank you Carlos and good luck with your President project. 73

[@serwiscbradioelektronikary2092]

Good Job Peter Good luck from Polamd

[@TRXLab]

Thank you and best wishes over to Poland! 73

[@mrbambix]

Hi Peter is there anything special about the device needle you used to inject the signal from your frequency generator? Thanks again for a great video. Greetings, Leo

[@TRXLab]

no really nothing only ceramic cap in line 47nF/100Volt that's it

[@iosartwork]

Hi Peter, I have a kenwood ts 2000 with a problem of reception. Can I send it to you? Best regards, Rémy

[@robertcalkjr.8325]

Nice job Peter, thanks!

[@TRXLab]

Glad that you liked it Robert, thanks!

[@richardcook4643]

Thanks for another great repair video. Does anyone have a link to the dbm conversion chart ? Thanks

[@TRXLab]

Try this Richard....kzbin.infocommunity

[@richardcook4643]

Got it. Thanks Peter. I appriciate all you do! 73

[@TKomoski]

Having watched you over the years Peter, I tried to determine what the problem was before you opened it. I figured that it was the RF front end, because you did have received but distorted at low db. I was hoping you would test the transistor and you did Good. Do you think that aging of the components in that stage caused the transistor to breakdown over time? Why wouldn't the attenuation stage before the 1st stage RF be a problem of the lose in Sinad? Well anyways I say to much, always a Pleasure to watch with my coffee on a saturday morning. Keep up the good work Peter see you next time on the TRX Bench, *_Ciao_* *73*

[@TRXLab]

Wow yeah you are right "over the years" I did not really realised that...Well ageing, I don't think that it was aging in this case but I have seen germanium transistors which were electrically DC wise completely fine but were producing heavy audio distortion and I have seen hf silicon transistors which were showing a good dc behaviour but totally failed in the circuit. That might have been an ageing issue but also a heat issue or both. In this case I think it was a lighting surge Thanks for watching Tom! 73

[@jonka1]

When I saw the nature of the distortion I immediately suspected a silicon device, (transistor or filter). I have seen many fail as two diodes but not always in positions where they could be affected by esd.

[@bblod4896]

Great diagnostic work. I like your injection probe. Did you build it? Thanks for the lesson.

[@TRXLab]

Thank you. Yes it is diy with an cap in the path to block dc back to the generator...

[@mrbambix]

TRX Bench can you tell us what cap? Thank you, Leo

[@TRXLab]

ceramic cap 47nF/100Volt

[@mrbambix]

@@TRXLab thanks Peter i will build something simular for my signal generator

[@ThomasHart59]

I was hoping to see you replace the light for the display. :-)

[@TRXLab]

Well Thomas I have to do what I have been asked for....

[@ThomasHart59]

@@TRXLab Of course! You never know... Maybe the owner wanted the left side of his radio to be invisible in daylight! If he didn't ask.... :-D

[@zeproo]

Another dying patient saved. Peter must be the upper God for the radio lovers !

[@TRXLab]

oh surly not the upper god I just try to help my radio friends. That's all...Thanks for stepping by 73

[@VicGreenBitcoin]

Vroeger noemde we dat 27mc Spitbakken.

[@glynnhm0lsg308]

good job

[@TRXLab]

Thanks Glynn

[@PhillRobinson]

If you do not hear nothing you must hear something

[@stargazer7644]

The real question is, who the heck was President James?

[@TRXLab]

lol, do you have an answer?

[@stargazer7644]

@@TRXLab They appear to also have a President Johnny, Walker, Andy, Bill and Randy. I know Johnny Walker, he isn't a president :)

[@fnordist]

CB Schrott, ein Varistor hätte den RX-Transistor vor Überspannung geschützt...