DAM! The first VIDEO WORTH A DAM that realy shows real trouble shooting and explained so everyone can see and hear the propper way to test and REPAIR a radio properly AWESOME JOB FRIEND other cb repair videos could take lessons from you 73
There is a purpose for "splatter box radios in big trucks. Many times hauling freight with others around you hauling freight...we talk on radios and switch to a different channel from 19. Lots of times when we're done talking, we forget to go back to 19. If a truck going the opposite way warns me of an incident on 19 but my radio is on 23 I can hear them if their radio bleeds badly on other channels. Happened to me, and I saved at least 2 lives. Harmonics is Rock n Roll. I would only drive with a splatter box...but if I run with someone I will switch down to 1/2 watt.
Your video and natural teaching skills are greatly appreciated. Thanks to this video and your explaining what you was doing I was able to fix my Mirage 88. My radio had a faulty TR-26. I replaced it with a new one along with capacitors, one back by where power enters the radio and a 1000 uf near the audio IC. Thanks a bunch.
I really appreciate your videos. You are a natural teacher. I’ve dabbled in radios for a few years but been doing more and more these last 6 months. Your basic how to vids are the best.
I couldn't have said it any better! I'm not into transceiver repair per se', but it's always great to see the basics executed so perfectly, I always learn some cool trick to use, which means they did their job as an educator! ~Jack, VEG
Loved it. Excellent video. Lots of useful information for working on any electronic device. Camera placement and lighting are also great. Seems so difficult and appears so easy. Thanks
Great video Buddy I like the way you used the microscope to really show that bad solder connection. Your advise on the big diode across the DC input sends a really important message to those who think big is better. Cheers my friend Greg VK2ZEZ.
Buddy, Thank you for this video. For me not knowing very much about radio repair these types of videos really help me out. You guys know you stuff for sure. If you haven't already done a video on the X Y box I would really be interested in that and I'm sure I'm not the only one. Once again Buddy, thank you for your Time! Joel
Thanks Joel. I will be doing a series of videos on basic troubleshooting like this in the future. For the X/Y box I will post a video link from Alan w2aew that has already done a video on.
This is wild. So essentially the General A.P. Hill, Galaxy DX33, and Connex CX4300 are all the same radio with different front panel lay-outs, and a few components on the board. As I forgot to date my Connex CX4300HP on the chassis when I bought it, I was able to glean from the Galaxy DX33 website that my radio was built in Shanghai on April 2005 which I purchased in May/June '05. I date my radios so I know when I bought them and how long I've had them, so finally my Connex is dated. I did follow along with you on my Connex and it too has had TR32 removed however my radio does not have sideband so I'm not all freaked about that. All the rest including solder joints looks good.
GREAT TEACHING SIR, i have a voyager RV radio and cd player, and sometimes sound would stop sounding, and play with the buttons, and it come back, next sound is gone for good, and to get schematics is hard cause unknown radio for RV, i will follow your style of troubleshooting to get my radio back to sound somehow, oh, aux thru earphones has sounds but not to speakers, ANY IDEAS? Miguel
nicely done Buddy i know how much extra time makeing that video added to that repair and i for one appreciate the effort. you did make a great job of explaining the process well done
Thanks Gary for the kind words. It was just a last minute decision to do the video. Really glad I did.I plan to do more using the Cobra 29 as a standard learning platform. Cover each section and pork through them.
Hey Buddy, I really enjoyed this video. Thank you so much for sharing your knowledge on how to trouble shoot these radios in a step by step manner that is very easy to follow. You do great work. Lynn, KJ3V
The first thing I would of done after a visual check is test the vco frequency, as that tells you straight away if the main voltage rail, PLL, reference crystal, loop crystal and VCO are ok.
First thing I do after looking around is to check if the radio VCO is in lock. These days I will not look at a radio that a screwdriver so called expert has been inside, it is so time consuming! Trying to hunt down missing parts for some radios is just almost impossible.
If you have any experience with the Yaesu FT-301S, I'd love to watch hours worth of your work on that. Callsign here is NG7I by the way. Just got an FT-301S from eBay and it's DOA. Well, it turns on and the controls function but the VFO isn't tuning or the clarifier. I injected a 9MHz signal to the RF section and it saw that, but I couldn't tune around it. The 6V v-reg supplying the various parts of the radio is good too (5.98v). Trying to locate a service manual for it but I'm not sure one exists. The operating manual is fairly extensive and it's gotten me to where I am now, but I really need test point voltages and expected waveforms at various spots with the scope. Not in any hurry to get this rig on the air, and I really kinda relish the idea of refreshing my electronics knowledge with it. So it's become my project. It's a really cool radio too. Kinda partial to the old analog stuff. It's a solid state version of something you'd expect to find from a WW2 military surplus outlet. At least that's the vibe I get when I look at it. Like a BC-348 or a BC-344. They made a digital display version (FT-301D) but the analog version just seems cooler in my opinion -lol
3 หลายเดือนก่อน
I got a free Cobra Sound Tracker from 1998 production that I have to figure out how to un-modify because it was setup somehow to be a half channel radio for taxi or some other use.. I found a couple chip components soldered onto the back of the board that should not be there but it is looking like a long term winter project and might be impossible without a schematic.. =+=EDIT I guess there are tons of free schematics and troubleshooting guides with test point voltages and scope signals on the internet so it just got a lot easier..
Thanks - a great insight into electronics troubleshooting!
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Well 7 years later and pretty much all these radios are made in China with cheap parts and skimped on electronics on the boards.. Just a few dollars worth of parts to make better first and second stage filtering would go a long way.. They have come out with digital filter circuit chips that are cheap enough to put in "value" radios that do a very good job of notching out harmonic spikes and clean up the transmit carrier pretty well.. But it still takes tuned R-C/L-C filters on the finals to catch them all..
Thanks so much for your helpful advice on your helpful tips on how to trouble Shoot circuits and to properly work on them and doing things right there are a lot of so call radio technician dining the wrong thing thanks so much keep the good videos coming ted KD2ARD....
Hi there to The Radio Shop. I am very new to this. Just quickly commenting to ask if there is a way here in TH-cam start at #1. I ask because the videos are curious and i am a little curious if i can learn from them?😀
hi so ...galaxy dx 949 and dx 959 are not good radios....? im old school and that uniden 980 ssb is a nice radio till the whole display burns out .....who makes a good ssb radio for the people without a fortune to spend ? .............great video......im gonna learn alot on your channel .....thanks for taking the time to shear your knowledge......................eric.......
great video Buddy. I am working on an old general lee. This radio transmits but has no audio or PA. I took the voltage at tr36, 9volts dc on collector. I went to Pin 5 of IC5 and the voltage is 4.03. Changed out C90 with no effect. Having a hard to trying to find out why the voltage is low R122 is ok.
yet another golden screwdriver special. i bet it was a good radio at one time b4 it was messed with.. very educational buddy really enjoyed the video :)
I have a Uniden PC78LTW similar to the cobra 29 LTD CLASSIC. I have receive, but no transmit. I installed the IRF520 mosfet mod, variable power, replac ed some electrolytic caps to include c112, c119. Replaced the IRF 520 Three times to see if the final was badeach time and finals were all good. Checked voltage regulator at front of radio which gets hot, but working. Replaced r19 by the PLL. Whatever is going on is temperature sensitive. If I put the radio in the freezer for a while the transmit comes back at times and for a while. After a few adjustments peaking out the radio it just quits again. Need your help, Thanks ! !
The Radio Shop This Uniden PC78LTW has not worked in years so I wanted to bring it back to life. The radio tweaked in very well after the mosfet mod, variable power, talkback, enhanced receive, echo board mod and led receive indicator. Now the radio only has great receive, but when keyed transmit LED goes out and there is no transmit. Have checked various transistors, caps and diodes. There is no voltage to c71 or IC # 3. Whatever was temperature sensitive has opened up and not allowing the radio to key up. Still checking components......
Let me start by saying that I enjoy each and every video you put up and I learn something every time I watch one. Now I have a question I am hoping you can answer for me without taking up to much of your time. The question relates to tube type ham radios only. Let's say you want to check a radio starting at the antenna of a radio what is a rule of thumb about where in the circuit or what part of a tube you would attach your o-scope probe lead to continue to trace the signal going into the radio?
Thanks Kevin for that great comment and question. First when ever tracing through tube radios it is always good to have a DC block attached to the test gear. This will stop any voltage from taking out the front end of generators and SA. Make sure your scope can handle the voltage of the circuit. Most test points would be the grids of the tubes. I think it was Paul at Mr Carlsons lab and Do at Restoroldradios have shown this in their videos. I will make this a future video.
Hi to Radio Shop. Perhaps I should apologize because I hear in the video that you do not like working on the radios before I say ask something. Here goes the question: Can an individual, say myself, learn from looking at the inside of a radio? I am just a little cuious if everyone is just a little bit smarter than me at acquiriing knowledge or am I not smart enough to learn or just a little bit plain lazy and not putting in enough effort to learn and understand radios and radio electronics. I look forward to any comment that I could receive from you.😀👍👍👁
I think its a great video. I like how you showed the noisy signal coming out of the radio. I hope you do another video at some point talking more about this. Maybe if there is any way we can check a radio without a spectrum analyzer?
In the past alignment procedures told you to adjust the 54MHz trap circuit for minimum shown on a television. A simple little old analog black and white portable television works just fine.
Yep Mike is right about using the TV, Also a scanner that receives 50 MHz will work. I will most likely do a lot more videos on troubleshooting for the beginner using the Cobra 29. Thanks for commenting
I'm a long-time CB "fixer-upper", and I can tell you this: Even a used, "cheaper" spectrum analyzer can be VERY pricey! The idea of using an old TV that is set to channel 2, or a scanner set to around 54 mHz will get the job done.
Great video! What is a standard value diode for revers polarity? Often times I never have the right one when a radio comes in blown. I need to order a bad of them lol
Any idea what would cause the vco to have no voltage adjustment? I have over 6 volts on a mk2 cobra 148gtl-dx but adjusting the vco does nothing to change it. ? Thanks.
Black splatter box special. Good to keep around the shop as a general purpose noise generator. I really don't know what people see in these things that makes them want them so bad. Bad solder joint, figures. See that so often its sad. Thats why I begin repairs with a really good inspection on the solder side of the board. Amazing how many radios can be fixed with nothing more than a visual inspection and soldering iron. The factory solder work on radios these days is so poor its really sad.
Yep the solder is almost just a layer. No puddles at all. Those halo's form quick. reminds me when I worked at Curtis Mathis, A roll of solder and a iron would fix most of the TV sets I worked on.
I got a used Mirage 88 that smells like a pork bbq. It must have been used close to a smoker. It's a splatter box. I use it on 27.185 in my big truck. I love it.
What size o-scope is the smallest you can use to check CB Radios with for seeing you modulated output? Do you have links to your DIY instruments you use to test with like the external radio meter and the X and Y box so people can get started testing their own radios instead of a truck-stop chop shop.
A few things... About 12 minutes in, you mention TR32 has been removed. How do you know that this part has been removed, without having the proper board schematic? It looks like many of the silkscreen parts are depopulated, how do you know this one is actually missing? When measuring your 10.24 Reference oscillator (and your mixer/other RF signals, for that matter), wouldn't you load the circuit using a regular passive probe? How do you know you are measuring the expected result, an not just something that is falling out from the loaded oscillator not behaving as it should in circuit? Another general question I have, when you're using bench equipment to provide signal to your receiver, how do you know what is a safe level to provide is? I've looked through datasheets/equipment specs, and it doesn't seem to be provided (at least on my equipment) Also, it maybe be worth mentioning that a longer exposure setting may make viewing waveforms on your cathode ray equipment a bit easier. Thanks for the great videos!
Lots of good questions here. I did make a comment in the video that this chassis was based off the original export radio board 11B. It is the basic building block. so if you went to cbtricls and went to the galaxy radio schematic database you will find the DX11B. Now about all those manuals in there are off this original. I will leave a link below to the 11B. Next question answer is in cb radios these signals are pretty strong so loading them down is not much of a problem. However in this demonstration the probe I used was isolated wit ha capacitor. Next question on bench equipment., I always start off with the lowest setting first then move up till I hear the required signal. Again a signal generators should not damage a cb radios receiver. And for the last question. Yep, my camera is a pita to go in and change the settings for exposure. If the video was mostly about waveforms then yes I change it. But for a few second shot I just leave it as is. Another reason I want to upgrade my video equipment in the future. So I do not have such a hassle at changing settings and the videos will be more pleasant for you guys. Appreciate the response you provided.
So many of us appreciate your hard work out here. Let me ask you what was that liquid you seemed to have squirted on the circuit board before you melted the solder?. Keep up the great videos. TTFN....
Are you willin' to disclose your flux to the rest of us? Or, is it a trade secret? I, too have often thought of making my own flux. Most recipes are pretty simple and can be made from all natural ingredients like pine cone leaves.
I just got a hold of an old Radio Shack TRC-448 CB radio to experiment with. I've recapped it and upon powering it up I found that the final transistor is bad, I intend to replace the driver and final output transistor pair (2SC2020 DRIVER AND 2SC1307.FINAL) I found the Chinese replacement transistors online but I've so many comments about those sometimes being "fake". On the other hand I also found the NTE235 and NTE236 replacements. Is it OK to use the NTE replacements. Any suggestions? Merry X-mas de Ernie AJ4BP
Good video. I agree, a good training radio. Has all the headaches that you can imagine. Personally, I wouldn't waste time in trying to repair one, they just aren't worth it.
Did you ever find out why your FT-101 had -167 volts instead of -100 volts? Just was wondering if will a voltage that far off would be OK in such an old radio. Anyway I like your videos they among others are better the watching TV.
Yep, line voltage and old parts. Planning on covering this in a future video. I had footage of this already but during Mathew I lost my main computer in the shop which corrupted the drive. Lost over 50 hours of footage. Thanks for watching and glad you like them.
Sir, this video of yours is do detailed and I liked the close ups' and most is the magnified ones for us viewers to see clearly. Anyway sir, do you have an email address that I can drop some of my questions? Sure do appreciate it.
Dear Mr ... My name is Marcus Motta and I live in the state of São Paulo Brazil. I have a CB Radio Cobra 148 GTL serial number 83018940 (by Taiwan) - an old model from 1980/90. I spent a long time without operating the radio and now when I turn it on, I realize that it doesn't receive any signal at all on channels ... only QRM (noise) ... Some indication of what could be happening ??? ... some diode or electrolytic capacitor???...lamentably I do not have the wiring diagram. thanks for your attention ... Motta, Marcus
Ones agin nice helpful advice... On how to do thing the correct way .... I have a question I like to forward to you if you could be of some assistance to me , an issue i have with a older model ranger RCI-2950 the issue I am having with the radio is it's coming on but i have no functions on front panel like to troubleshoot this problem just looking if you may have ran in to a similar problem with order radios in the pass troubleshooting the UPC circuits boad with an issue of something go wrong in the the circuit board and found the problem... Do you have a regular email address to contact you directly thanks ted Dean KD2ARD... Keep the great videos coming... hopefully you can help me with this problem... Looking forward to your reply thanks so much...
man thanks for that its very helpfull!!! those are real splatter boxes... a neighboor had one of those with a EL cheapo linear amp..... HORRIBLE splatter over all 40 chanels... even splatering over USB and LSB and analog tv as well... I told him that he was causing harmfull interference and he didnt cared.... gess what, his crappy linear amp let the smoke out Its been two month, and I havent heard him on air since then
Thanks Hugo. Yep lived near to some like that also. Finally got him to let me tune up his radio and the problem went away. Crappy signal into a crappy amp makes it worse.
That large of a diode is it really needed on that cb ,when.selenium rectififer are replaced with a 1n 4007 one amp.diode with a dropping resistor is enough for a tube radio ,and a much larger diode is used with a sold state radio would a higher amp diode be ok to use in a tube radio ,if you didn't have a 1n4007 1amp diode ,I wondering what happen when you use higher ampage diode then need is it ok anyone
![Stop RF "Radio Frequency" Interference! [Ways To Solve Noise Issues]](/img/n.gif)
DAM! The first VIDEO WORTH A DAM that realy shows real trouble shooting and explained so everyone can see and hear the propper way to test and REPAIR a radio properly AWESOME JOB FRIEND other cb repair videos could take lessons from you 73
I appreciate the kind words.
There is a purpose for "splatter box radios in big trucks. Many times hauling freight with others around you hauling freight...we talk on radios and switch to a different channel from 19. Lots of times when we're done talking, we forget to go back to 19. If a truck going the opposite way warns me of an incident on 19 but my radio is on 23 I can hear them if their radio bleeds badly on other channels. Happened to me, and I saved at least 2 lives. Harmonics is Rock n Roll. I would only drive with a splatter box...but if I run with someone I will switch down to 1/2 watt.
I like how you always know what to look for next and next and next until you find it. Man this is awesome info here! Thanks for sharing!
Thanks for the nice comment. I always try and use basic logic when trouble shooting radio.
You’re one of the clever ones. It’s clear you’re tapping in to a wealth of knowledge. Very instructive video!
Your video and natural teaching skills are greatly appreciated. Thanks to this video and your explaining what you was doing I was able to fix my Mirage 88. My radio had a faulty TR-26. I replaced it with a new one along with capacitors, one back by where power enters the radio and a 1000 uf near the audio IC. Thanks a bunch.
Glad it was helpful! Thanks for stopping in,
I really appreciate your videos. You are a natural teacher. I’ve dabbled in radios for a few years but been doing more and more these last 6 months. Your basic how to vids are the best.
Wow, thanks!
THANK YOU SO MUCH FOR TAKING THE TIME TO MAKE THESE VIDEOS......MANY THANKS
Thank you for watching
Good for anyone wanting to learn more about radio + electronic.
Appreciate you sharing your knowledge... salute....
Enjoy watching you and Mike work..... always very interesting! Keep up the good work.
I couldn't have said it any better! I'm not into transceiver repair per se', but it's always great to see the basics executed so perfectly, I always learn some cool trick to use, which means they did their job as an educator! ~Jack, VEG
Thank you Scott.
Thanks also for that nice comment Jack.
Loved it. Excellent video. Lots of useful information for working on any electronic device. Camera placement and lighting are also great. Seems so difficult and appears so easy. Thanks
Thanks for watching. Appreciate the kind words.
Great video Buddy I like the way you used the microscope to really show that bad solder connection. Your advise on the big diode across the DC input sends a really important message to those who think big is better. Cheers my friend Greg VK2ZEZ.
Most appreciated Greg. Yep those big diodes spell disaster lol. Thanks for watching.
Buddy, Thank you for this video. For me not knowing very much about radio repair these types of videos really help me out. You guys know you stuff for sure.
If you haven't already done a video on the X Y box I would really be interested in that and I'm sure I'm not the only one. Once again Buddy, thank you for your Time! Joel
Thanks Joel. I will be doing a series of videos on basic troubleshooting like this in the future. For the X/Y box I will post a video link from Alan w2aew that has already done a video on.
th-cam.com/video/y4Zt_LJX1Tc/w-d-xo.html
Appreciate this video. You just got another subscriber. Thanks for what you do, Sir.
Buddy, I love your forthright approach to these import radios. We must keep the airways clean and legal.
😂😂😂 how sweet lol😭😭.
This is wild. So essentially the General A.P. Hill, Galaxy DX33, and Connex CX4300 are all the same radio with different front panel lay-outs, and a few components on the board. As I forgot to date my Connex CX4300HP on the chassis when I bought it, I was able to glean from the Galaxy DX33 website that my radio was built in Shanghai on April 2005 which I purchased in May/June '05. I date my radios so I know when I bought them and how long I've had them, so finally my Connex is dated. I did follow along with you on my Connex and it too has had TR32 removed however my radio does not have sideband so I'm not all freaked about that. All the rest including solder joints looks good.
I really enjoyed your detailed troubleshooting video.
Thank you very much
Great video! Thanks for taking the time to share with us.
You are very welcome Darryl and thanks for watching.
WOW, fantastic information. Thank you!
Our pleasure!
GREAT TEACHING SIR, i have a voyager RV radio and cd player, and sometimes sound would stop sounding, and play with the buttons, and it come back, next sound is gone for good, and to get schematics is hard cause unknown radio for RV, i will follow your style of troubleshooting to get my radio back to sound somehow, oh, aux thru earphones has sounds but not to speakers, ANY IDEAS? Miguel
nicely done Buddy i know how much extra time makeing that video added to that repair and i for one appreciate the effort. you did make a great job of explaining the process well done
Thanks Gary for the kind words. It was just a last minute decision to do the video. Really glad I did.I plan to do more using the Cobra 29 as a standard learning platform. Cover each section and pork through them.
@@TheRadioShop Amen
Hey Buddy, I really enjoyed this video. Thank you so much for sharing your knowledge on how to trouble shoot these radios in a step by step manner that is very easy to follow. You do great work. Lynn, KJ3V
great video good shots using microscope, bk1801 was my first counter
Wait till I get all the other video stuff set up. Hope it will be better. The 1801 is still a rock solid counter. Thanks Dennis
Thank you Buddy, waiting for the next one.
Thanks for watching.
Truckstop back door junk. But this was a great video. Good job finding the trouble.
Very good video!! So much information, thank you, please continue to share ...
The first thing I would of done after a visual check is test the vco frequency, as that tells you straight away if the main voltage rail, PLL, reference crystal, loop crystal and VCO are ok.
That's my first test after a visual inspection. Grab a scope probe and check for proper frequency generation.
Good Point!
First thing I do after looking around is to check if the radio VCO is in lock. These days I will not look at a radio that a screwdriver so called expert has been inside, it is so time consuming! Trying to hunt down missing parts for some radios is just almost impossible.
Great Job buddy. Nice to see troubleshooting .
Thanks Grant. Good to see you.
Man, you're great to watch! Thank you for the time you took to share your experience and knowledge.
And thank you for the time you put in to watch
If you have any experience with the Yaesu FT-301S, I'd love to watch hours worth of your work on that. Callsign here is NG7I by the way. Just got an FT-301S from eBay and it's DOA. Well, it turns on and the controls function but the VFO isn't tuning or the clarifier. I injected a 9MHz signal to the RF section and it saw that, but I couldn't tune around it. The 6V v-reg supplying the various parts of the radio is good too (5.98v).
Trying to locate a service manual for it but I'm not sure one exists. The operating manual is fairly extensive and it's gotten me to where I am now, but I really need test point voltages and expected waveforms at various spots with the scope. Not in any hurry to get this rig on the air, and I really kinda relish the idea of refreshing my electronics knowledge with it. So it's become my project. It's a really cool radio too. Kinda partial to the old analog stuff. It's a solid state version of something you'd expect to find from a WW2 military surplus outlet. At least that's the vibe I get when I look at it. Like a BC-348 or a BC-344. They made a digital display version (FT-301D) but the analog version just seems cooler in my opinion -lol
I got a free Cobra Sound Tracker from 1998 production that I have to figure out how to un-modify because it was setup somehow to be a half channel radio for taxi or some other use.. I found a couple chip components soldered onto the back of the board that should not be there but it is looking like a long term winter project and might be impossible without a schematic.. =+=EDIT I guess there are tons of free schematics and troubleshooting guides with test point voltages and scope signals on the internet so it just got a lot easier..
Nice to see showing the basics ,love your vids Nigel sydney vk2pha
Thanks Nigel/ It is fun to help others.
Great troubleshooting tips Buddy, thanks!
Hi Dino, Just simple stuff my friend. Thanks for commenting.
Great job
Good video just trying to learn here
Thanks
Glad to hear it
Another great video keep them coming.
Thanks Edward
Thanks - a great insight into electronics troubleshooting!
Well 7 years later and pretty much all these radios are made in China with cheap parts and skimped on electronics on the boards.. Just a few dollars worth of parts to make better first and second stage filtering would go a long way.. They have come out with digital filter circuit chips that are cheap enough to put in "value" radios that do a very good job of notching out harmonic spikes and clean up the transmit carrier pretty well.. But it still takes tuned R-C/L-C filters on the finals to catch them all..
Thanks so much for your helpful advice on your helpful tips on how to trouble Shoot circuits and to properly work on them and doing things right there are a lot of so call radio technician dining the wrong thing thanks so much keep the good videos coming ted KD2ARD....
Thanks Buddy for the video and keep 'em coming!
great video Buddy! Thanks for sharing 73
Thanks for watching Peter. Simple troubleshooting.
Great video Buddy! Thank you for taking the time to share this with us.
No problem, Just showing like if you were there beside me. :-) Thanks my friend.
Great video!
great video.. and spot on correct about the export radios being garbage..
Thank u very much
Very easy to follow .. thanks
Between the phone and the doorbell I dont know how you get anything done..great video..
Sometimes it is a challenge. Thanks for watching.
This is excellent video.
Excellent video! Thanks for sharing!
Thanks for the kind words my friend
Hi there to The Radio Shop. I am very new to this. Just quickly commenting to ask if there is a way here in TH-cam start at #1. I ask because the videos are curious and i am a little curious if i can learn from them?😀
hi so ...galaxy dx 949 and dx 959 are not good radios....? im old school and that uniden 980 ssb is a nice radio till the whole display burns out .....who makes a good ssb radio for the people without a fortune to spend ? .............great video......im gonna learn alot on your channel .....thanks for taking the time to shear your knowledge......................eric.......
Good video, Buddy. Good camera technique. The video is interesting and easy to follow. 73 Tom KY4TD
Thanks for the kind words Tom. Glad you found it of interest.
Nothing like a good ol coil spreader.
awesome video
great video Buddy. I am working on an old general lee. This radio transmits but has no audio or PA. I took the voltage at tr36, 9volts dc on collector. I went to Pin 5 of IC5 and the voltage is 4.03. Changed out C90 with no effect. Having a hard to trying to find out why the voltage is low R122 is ok.
Mad just need the audio ic replaced have you checked it? 73s
yet another golden screwdriver special. i bet it was a good radio at one time b4 it was messed with..
very educational buddy really enjoyed the video :)
Thanks very much Scott.
I have a Uniden PC78LTW similar to the cobra 29 LTD CLASSIC. I have receive, but no transmit. I installed the IRF520 mosfet mod, variable power, replac ed some electrolytic caps to include c112, c119. Replaced the IRF 520 Three times to see if the final was badeach time and finals were all good. Checked voltage regulator at front of radio which gets hot, but working. Replaced r19 by the PLL. Whatever is going on is temperature sensitive. If I put the radio in the freezer for a while the transmit comes back at times and for a while. After a few adjustments peaking out the radio it just quits again. Need your help, Thanks ! !
One question. Did the radio work ok before you started changing all those parts?
The Radio Shop
This Uniden PC78LTW has not worked in years so I wanted to bring it back to life. The radio tweaked in very well after the mosfet mod, variable power, talkback, enhanced receive, echo board mod and led receive indicator. Now the radio only has great receive, but when keyed transmit LED goes out and there is no transmit. Have checked various transistors, caps and diodes. There is no voltage to c71 or IC # 3. Whatever was temperature sensitive has opened up and not allowing the radio to key up. Still checking components......
Thank you for the info.
great video dude... ill be back!
Let me start by saying that I enjoy each and every video you put up and I learn something every time I watch one. Now I have a question I am hoping you can answer for me without taking up to much of your time. The question relates to tube type ham radios only. Let's say you want to check a radio starting at the antenna of a radio what is a rule of thumb about where in the circuit or what part of a tube you would attach your o-scope probe lead to continue to trace the signal going into the radio?
Thanks Kevin for that great comment and question. First when ever tracing through tube radios it is always good to have a DC block attached to the test gear. This will stop any voltage from taking out the front end of generators and SA. Make sure your scope can handle the voltage of the circuit. Most test points would be the grids of the tubes. I think it was Paul at Mr Carlsons lab and Do at Restoroldradios have shown this in their videos. I will make this a future video.
Thank you very much and I look forward to your instructional video
Very helpful, thank you sir!
Nice video buddy big thumbs up I like the set up on your oscilloscope would love to see what's in that metal box 73
Thanks alan. I need to do a video on that but Alan w2aew has already.th-cam.com/video/y4Zt_LJX1Tc/w-d-xo.html
Hi to Radio Shop. Perhaps I should apologize because I hear in the video that you do not like working on the radios before I say ask something. Here goes the question: Can an individual, say myself, learn from looking at the inside of a radio? I am just a little cuious if everyone is just a little bit smarter than me at acquiriing knowledge or am I not smart enough to learn or just a little bit plain lazy and not putting in enough effort to learn and understand radios and radio electronics. I look forward to any comment that I could receive from you.😀👍👍👁
Thank you, Thank you. Can't wait for the 29.
I will do a series on this using the 29 in the future. Thanks for watching.
I think its a great video. I like how you showed the noisy signal coming out of the radio. I hope you do another video at some point talking more about this. Maybe if there is any way we can check a radio without a spectrum analyzer?
In the past alignment procedures told you to adjust the 54MHz trap circuit for minimum shown on a television. A simple little old analog black and white portable television works just fine.
Yep Mike is right about using the TV, Also a scanner that receives 50 MHz will work. I will most likely do a lot more videos on troubleshooting for the beginner using the Cobra 29. Thanks for commenting
I'm a long-time CB "fixer-upper", and I can tell you this: Even a used, "cheaper" spectrum analyzer can be VERY pricey! The idea of using an old TV that is set to channel 2, or a scanner set to around 54 mHz will get the job done.
Great video! What is a standard value diode for revers polarity? Often times I never have the right one when a radio comes in blown. I need to order a bad of them lol
It is best to replace with the same as what was used in the radio. If unsure or cannot find a schematic a 1N4003 will work.
@@TheRadioShop thank you
Very good video.
Thank you
Wondering if you have done a video of a complete alignment start to finish?
As of yet know. No one seems to want that.
Any idea what would cause the vco to have no voltage adjustment? I have over 6 volts on a mk2 cobra 148gtl-dx but adjusting the vco does nothing to change it. ? Thanks.
thank you for sharing
My pleasure
Interesting and informative video Buddy - thanks for posting. 73, Bill.
Thanks for watching Bill
Black splatter box special. Good to keep around the shop as a general purpose noise generator. I really don't know what people see in these things that makes them want them so bad.
Bad solder joint, figures. See that so often its sad. Thats why I begin repairs with a really good inspection on the solder side of the board. Amazing how many radios can be fixed with nothing more than a visual inspection and soldering iron. The factory solder work on radios these days is so poor its really sad.
Yep the solder is almost just a layer. No puddles at all. Those halo's form quick. reminds me when I worked at Curtis Mathis, A roll of solder and a iron would fix most of the TV sets I worked on.
@@TheRadioShop It still does
The difference between classical and punk rock ...to the truck driver, and your local agitator that likes loud distortion.
I got a used Mirage 88 that smells like a pork bbq. It must have been used close to a smoker. It's a splatter box. I use it on 27.185 in my big truck. I love it.
ab5ni still laffin and well said...i use one word ”urban”, ha
Nice Job Buddy. Again, our old friend the voltmeter to the rescue.
Thanks Vern. Yep, simple problem and the voltmeter sniffed another one out. Thanks for stopping in.
Thanks for this video it has really helped me a lot.
Thanks, Glad it helps.
I cannot find the schematic for this board? where did you find it at?
I cannot remember which radio this was. but go to this link and pick anything older galaxy. All the same.
www.cbtricks.com/radios/index.htm
What are the 2 source coils? Fuse resistor or inductor?
What size o-scope is the smallest you can use to check CB Radios with for seeing you modulated output? Do you have links to your DIY instruments you use to test with like the external radio meter and the X and Y box so people can get started testing their own radios instead of a truck-stop chop shop.
Hi William. I just posted video #107 and your answer is there my friend. I think the video will help better.
A few things...
About 12 minutes in, you mention TR32 has been removed. How do you know that this part has been removed, without having the proper board schematic? It looks like many of the silkscreen parts are depopulated, how do you know this one is actually missing?
When measuring your 10.24 Reference oscillator (and your mixer/other RF signals, for that matter), wouldn't you load the circuit using a regular passive probe? How do you know you are measuring the expected result, an not just something that is falling out from the loaded oscillator not behaving as it should in circuit?
Another general question I have, when you're using bench equipment to provide signal to your receiver, how do you know what is a safe level to provide is? I've looked through datasheets/equipment specs, and it doesn't seem to be provided (at least on my equipment)
Also, it maybe be worth mentioning that a longer exposure setting may make viewing waveforms on your cathode ray equipment a bit easier.
Thanks for the great videos!
Lots of good questions here. I did make a comment in the video that this chassis was based off the original export radio board 11B. It is the basic building block. so if you went to cbtricls and went to the galaxy radio schematic database you will find the DX11B. Now about all those manuals in there are off this original. I will leave a link below to the 11B. Next question answer is in cb radios these signals are pretty strong so loading them down is not much of a problem. However in this demonstration the probe I used was isolated wit ha capacitor. Next question on bench equipment., I always start off with the lowest setting first then move up till I hear the required signal. Again a signal generators should not damage a cb radios receiver. And for the last question. Yep, my camera is a pita to go in and change the settings for exposure. If the video was mostly about waveforms then yes I change it. But for a few second shot I just leave it as is. Another reason I want to upgrade my video equipment in the future. So I do not have such a hassle at changing settings and the videos will be more pleasant for you guys. Appreciate the response you provided.
Link to DX11www.cbtricks.com/radios/galaxy/dx11b/index.htm
Good Fix Buddy!!👍👍👍
Thanks Aaron.
So many of us appreciate your hard work out here. Let me ask you what was that liquid you seemed to have squirted on the circuit board before you melted the solder?. Keep up the great videos. TTFN....
Thanks for the kind words. The liquid you saw was my homemade flux. It helps the solder to flow better.Thanks for stopping in.
Are you willin' to disclose your flux to the rest of us? Or, is it a trade secret? I, too have often thought of making my own flux. Most recipes are pretty simple and can be made from all natural ingredients like pine cone leaves.
Just pure rosin and IPA
Thank you.
I just got a hold of an old Radio Shack TRC-448 CB radio to experiment with. I've recapped it and upon powering it up I found that the final transistor is bad, I intend to replace the driver and final output transistor pair (2SC2020 DRIVER AND 2SC1307.FINAL) I found the Chinese replacement transistors online but I've so many comments about those sometimes being "fake". On the other hand I also found the NTE235 and NTE236 replacements. Is it OK to use the NTE replacements. Any suggestions?
Merry X-mas de Ernie AJ4BP
Yes the NTE replacements should work fine in these. And watch out for the fakes out there. Have a Merry Christmas
been very helpful, thanks
Thanks
Good job
Great Video, Thank You
Thanks Richard
Got a question - do you by chance know a transistor that will replace a ranger TDTC0114YS Transistor for AM Detector?
Interesting. I cannot find a substitute for that. I will check around.
Thank you very much.
where do you find these for brother? thanks
Good video. I agree, a good training radio. Has all the headaches that you can imagine. Personally, I wouldn't waste time in trying to repair one, they just aren't worth it.
The Radio Shop, You have more patience with this piece of _____ than I would. The "out bin" never looked so promising!
How to repair the am and fm station to the mini component please explain and help me. Thankz god bless
Did you ever find out why your FT-101 had -167 volts instead of -100 volts? Just was wondering if will a voltage that far off would be OK in such an old radio. Anyway I like your videos they among others are better the watching TV.
Yep, line voltage and old parts. Planning on covering this in a future video. I had footage of this already but during Mathew I lost my main computer in the shop which corrupted the drive. Lost over 50 hours of footage. Thanks for watching and glad you like them.
♥️👍
Sir, this video of yours is do detailed and I liked the close ups' and most is the magnified ones for us viewers to see clearly. Anyway sir, do you have an email address that I can drop some of my questions? Sure do appreciate it.
The link to the schematic and service information does not work.
Dear Mr ... My name is Marcus Motta and I live in the state of São Paulo Brazil. I have a CB Radio Cobra 148 GTL serial number 83018940 (by Taiwan) - an old model
from 1980/90. I spent a long time without operating the radio and now when I turn it on, I realize that it doesn't receive any signal at all on channels ...
only QRM (noise) ... Some indication of what could be happening ??? ... some diode or electrolytic capacitor???...lamentably I do not have the wiring diagram. thanks for your attention ...
Motta, Marcus
Amen brother 😅😅😅
very helpful video!
Thanks Chuck, always good to hear.
8:19 that was most likely done in the factory to fine tune it.
nice video
Ones agin nice helpful advice...
On how to do thing the correct way ....
I have a question I like to forward to you if you could be of some assistance to me , an issue
i have with a older model ranger RCI-2950 the issue I am having with the radio is it's coming on but i have no functions on front panel like to troubleshoot this problem just looking if you may have ran in to a similar problem with order radios in the pass troubleshooting the UPC circuits boad with an issue of something go wrong in the the circuit board and found the problem...
Do you have a regular email address to contact you directly thanks ted Dean KD2ARD...
Keep the great videos coming... hopefully you can help me with this problem...
Looking forward to your reply thanks so much...
man thanks for that its very helpfull!!!
those are real splatter boxes... a neighboor had one of those with a EL cheapo linear amp..... HORRIBLE splatter over all 40 chanels... even splatering over USB and LSB and analog tv as well... I told him that he was causing harmfull interference and he didnt cared....
gess what, his crappy linear amp let the smoke out Its been two month, and I havent heard him on air since then
Thanks Hugo. Yep lived near to some like that also. Finally got him to let me tune up his radio and the problem went away. Crappy signal into a crappy amp makes it worse.
That large of a diode is it really needed on that cb ,when.selenium rectififer are replaced with a 1n 4007 one amp.diode with a dropping resistor is enough for a tube radio ,and a much larger diode is used with a sold state radio would a higher amp diode be ok to use in a tube radio ,if you didn't have a 1n4007 1amp diode ,I wondering what happen when you use higher ampage diode then need is it ok anyone
Those radios are very well known for crappy soldering, especially around the VCO.
Dreadful junk but the PCBs are used in so many highly regarded rigs.
True Clint. The actual radio is not that bad in design. But the PLL is the weak link in them.
Can you please make a video on how to make a PTT switch?
You mean to manually key the radio while injecting a signal?