Let me share my working experiences with those 200GTL-DX's. The 4pcs prototypes which were developed in R&D center in South Korea in Y2004 were undoubtedly the best of their kind. They passed the engineering evaluation and electrical/RF tests required by Cobra Electronics Corporation. The prototype developer and engineer who worked in Maxon Thailand in the 90's was one of those who then formed the company/factory in Y2002 in the Philippines; this company mass-produced the GTL200-DX, GTL-150-DX, 19DX, PR-150, PR-3500 and other family radio service units. 50 pcs. of GTL200-DX were put into Pre-production. Obviously, as expected, problems were revealed as in anticipation with mass-production. The Nightwatch were easily busted / burned-out. The SSB envelope being viewed from the 40 Mhz oscilloscope were severely distorted at 100% modulation. These units then came into mass production, we encountered the very same problems with Nightwatch, distorted modulation envelopes and output power problems. When you mass-produce an electronic device, obviously you will revise the PCB layout to contain the patterns and connections that were not available in the prototypes. This would surely give you stray and parasitic capacitances and inductances which will then give bad outcome with regards to signal transmission & reception. Moreover, the supplier of those PCB's were different from the prototypes' because the mass-produced PCB's were cheaper. These issues really gave us hard times, I even got myself locked in the RF shielded room just doing repairs on so many defective units. We again revised the PCB's but just hardly improved the signal and output power performances. I then quit my job as the process engineer for those radios in Y2005. The links below are the photos of the once I dearly loved work. One photo was repairing dozens of technician-raped units after they were not able to troubleshoot 200GL-DX's and the other one was the actual production line were-in those radios were assembled, tested and packed for overseas shipment. Surely, they were just memories :-) ibb.co/sCjw5Kd ibb.co/b6W6XPm
You’re the guy that actually made these radios yet nobody is asking you questions. Lmao your comment must have been too long. I’m just getting into this hobby. So this might be a dumb question. Did they ever fix the problems with these units? I’m going to look at one tomorrow. The guy says it works perfectly. Should I stay away from it?
I just bought used Cobra 200 DX that doesn't work. No TX. Exact same issue as you have with this one. Same driver bad. Been replaced once already. I have one of the coppers gone on it. Going to try a repair like this. I worked with chip parts while at Delco Electronics as a tech. You sure do have to have the right equipment to work on it. I changed surface mounted fine pitch quad IC's out by hand. If you have the right stuff to work with it's not hard to do. Excellent video. I've never had to repair a circuit board copper that has been torn off and going to repair this one. We never used a damage board. I may do some repair video's myself.
I worked at a board plant in the early 80s. Quite the process to make a raw board. Once the fiberglass got in your clothes, it never came out. Wish I had squirrelled away some copper foil! We would do some gold foil for aerospace as well, had armed security guards in that whole process.
Thanks so much for the procedural tips. I've only done 2 trace repairs, and have struggled with how to trim the copper to fit. The tape on glass technique is genius! Thanks for taking the time to share. :-)
When I first started doing SMD I was so frustrated that I gave up for a while. I got a hot air station and started using solder paste and blam, It was so easy after that and some practice. It does take some practice on something you don't care about.
Nice work! I remember when soldering a 1206 part seemed like witchcraft. Now I solder 0201 parts with out much problem... I don't like soldering 0201 parts because breathing makes them move but I can solder them as long as I have a microscope. I solder 0402 parts with a magnifying visor or sometimes the microscope. It's definitely a right tool for the job kind of thing.
I think These faceplates were just common to discolor like that. I currently have one that is super dark brown Can't even see some of the lettering anymore because of it. I've searched for quite some time to try and find a replacement and I just have not had any luck. I'm thinking of having a sticker company just make me a sticker to put over the top. Love the radio though been a great talker for years now, no issue's. Great video. Thanks.
That's an awesome repair. What'd I do: solder a through hole resistor from the transistor lead to whatever was on the other side of that SMD resistor (with some heatsrink over it). Hoping the mounting screw provides sufficient mechanical support.
Part of the problem with the large driver, you have a large solder pad and the lead from the transistor drawing away the heat. By the time the pad is hot enough to remove the transistor, the pad and smd resistor falls off.
Yup, The first time I used my hot air I had the temp to high and it peeled the trace off of the board, so I had to repair the trace with a small wire. I learned and now it never happens to me.
i know your pain just got a galaxy 2517 guy tried to get more power ,,burnt up the board ..wish i can find a print that shows the voltage on xmit like sams do ,,i am real close but no output
I have one too . And the turn knob channel won’t respond to switch to a different channel . Do you have the schematic for this radio cobra 200 gtl DX ???
Sorry but I had this one bookmarked too far down in a folder and just got to it! Is that blue electrolytic sitting at an angle just below the repair area a bodge? Just curious...
If I was going to get a Citizens Band Transceiver I would go for a TEN-TEC much better than UNIDEN and is made by TEN-TEC in Dolly Parton Parkway in Nashville Tennessee.
DigiKey or any other electronics supplier should be able to provide it. Just measure the old control for dimensions. For a clarifier be sure it is a "linear" control and NOT "logarithmic ".
Advice Please!! My husband has a cobra 200 gtl dx and it will not light up or turn on at all. He had it plugged in, keyed up once and blew some kind of fuse because afterwards, the display and everything quit. Any ideas or tips on what to do to fix this problem, Mike?
I don't understand why your videos tell what you did. They are mostly you telling a story. Show people how it's done and where to test, how to scrape trace coatings, how to solder in the repair. We know you repair radio equipment. This is the 3rd video I watched and you just tell a story.
my nerves would not let me. i have always envious of people that do this kind of work
Let me share my working experiences with those 200GTL-DX's. The 4pcs prototypes which were developed in R&D center in South Korea in Y2004 were undoubtedly the best of their kind. They passed the engineering evaluation and electrical/RF tests required by Cobra Electronics Corporation. The prototype developer and engineer who worked in Maxon Thailand in the 90's was one of those who then formed the company/factory in Y2002 in the Philippines; this company mass-produced the GTL200-DX, GTL-150-DX, 19DX, PR-150, PR-3500 and other family radio service units.
50 pcs. of GTL200-DX were put into Pre-production. Obviously, as expected, problems were revealed as in anticipation with mass-production. The Nightwatch were easily busted / burned-out. The SSB envelope being viewed from the 40 Mhz oscilloscope were severely distorted at 100% modulation.
These units then came into mass production, we encountered the very same problems with Nightwatch, distorted modulation envelopes and output power problems. When you mass-produce an electronic device, obviously you will revise the PCB layout to contain the patterns and connections that were not available in the prototypes. This would surely give you stray and parasitic capacitances and inductances which will then give bad outcome with regards to signal transmission & reception. Moreover, the supplier of those PCB's were different from the prototypes' because the mass-produced PCB's were cheaper. These issues really gave us hard times, I even got myself locked in the RF shielded room just doing repairs on so many defective units. We again revised the PCB's but just hardly improved the signal and output power performances.
I then quit my job as the process engineer for those radios in Y2005. The links below are the photos of the once I dearly loved work. One photo was repairing dozens of technician-raped units after they were not able to troubleshoot 200GL-DX's and the other one was the actual production line were-in those radios were assembled, tested and packed for overseas shipment. Surely, they were just memories :-)
ibb.co/sCjw5Kd
ibb.co/b6W6XPm
You’re the guy that actually made these radios yet nobody is asking you questions. Lmao your comment must have been too long. I’m just getting into this hobby. So this might be a dumb question. Did they ever fix the problems with these units? I’m going to look at one tomorrow. The guy says it works perfectly. Should I stay away from it?
They didn't last long on the market for a reason. The production model had just too many design flaws
I just bought used Cobra 200 DX that doesn't work. No TX. Exact same issue as you have with this one. Same driver bad. Been replaced once already. I have one of the coppers gone on it. Going to try a repair like this. I worked with chip parts while at Delco Electronics as a tech. You sure do have to have the right equipment to work on it. I changed surface mounted fine pitch quad IC's out by hand. If you have the right stuff to work with it's not hard to do. Excellent video. I've never had to repair a circuit board copper that has been torn off and going to repair this one. We never used a damage board. I may do some repair video's myself.
I worked at a board plant in the early 80s. Quite the process to make a raw board. Once the fiberglass got in your clothes, it never came out. Wish I had squirrelled away some copper foil! We would do some gold foil for aerospace as well, had armed security guards in that whole process.
Thanks so much for the procedural tips. I've only done 2 trace repairs, and have struggled with how to trim the copper to fit. The tape on glass technique is genius! Thanks for taking the time to share. :-)
When I first started doing SMD I was so frustrated that I gave up for a while. I got a hot air station and started using solder paste and blam, It was so easy after that and some practice. It does take some practice on something you don't care about.
Nice work! I remember when soldering a 1206 part seemed like witchcraft. Now I solder 0201 parts with out much problem... I don't like soldering 0201 parts because breathing makes them move but I can solder them as long as I have a microscope. I solder 0402 parts with a magnifying visor or sometimes the microscope. It's definitely a right tool for the job kind of thing.
I think These faceplates were just common to discolor like that. I currently have one that is super dark brown Can't even see some of the lettering anymore because of it. I've searched for quite some time to try and find a replacement and I just have not had any luck. I'm thinking of having a sticker company just make me a sticker to put over the top. Love the radio though been a great talker for years now, no issue's. Great video. Thanks.
That's an awesome repair. What'd I do: solder a through hole resistor from the transistor lead to whatever was on the other side of that SMD resistor (with some heatsrink over it). Hoping the mounting screw provides sufficient mechanical support.
We need you Mike. Well I'll speak I'll for myself. I need you and your skills. Something on it's way out to on Thursday. Thanx. Another great clip.
Great repair video and advice!
I’m guessing you don’t do these videos anymore?
Great video Mike, some very tedious work, glad you have calm hands!
Thanks Mike for another great Vid. .You help remove the Fear.73
Hi Mike,
Another fine video. Appreciate you showing your techniques on circuit trace repair. 73 WB3BJU
Nice Job 👍🏻
Wow I don't think I could cut something that small and do what you did
Great video. Thanks for sharing.
Part of the problem with the large driver, you have a large solder pad and the lead from the transistor drawing away the heat. By the time the pad is hot enough to remove the transistor, the pad and smd resistor falls off.
Excellent video, Well done!
Yup, The first time I used my hot air I had the temp to high and it peeled the trace off of the board, so I had to repair the trace with a small wire. I learned and now it never happens to me.
Interesting, A forest of electrolytec capicators on the right side of the radio.
Hey Mike .... What's the trick getting that faceplate off I removed all knobs and the four little screws on the sides? WoW won't come off. 🤔🤔🤔
i know your pain just got a galaxy 2517 guy tried to get more power ,,burnt up the board ..wish i can find a print that shows the voltage on xmit like sams do ,,i am real close but no output
I have two of these
I have one too . And the turn knob channel won’t respond to switch to a different channel . Do you have the schematic for this radio cobra 200 gtl DX ???
Sorry but I had this one bookmarked too far down in a folder and just got to it! Is that blue electrolytic sitting at an angle just below the repair area a bodge? Just curious...
Another will done video, Mike. What epoxy do you use?
If I was going to get a Citizens Band Transceiver I would go for a TEN-TEC much better than UNIDEN and is made by TEN-TEC in Dolly Parton Parkway in Nashville Tennessee.
Is there a way to use magnets to hold down your trace???
Aweaome 👍
The point it is to fix correctly your cb radio NOT TO BOUCHED!!! Uderstand how to you tell!!!
I have a cobra 200gtl! Very good radio! I can’t find a replacement volume knob mine is shorting out. Do you have one or know where I can get one?
If it's scratchy n noisy. Clean w alcohol. Then 1 drop of light non conductive light oil and enjoy
Awesome lol
Mike happy New year to you good tecnian Mike can you help me with a cobra i42 gtl
I like to have you look at a radio
is it a 100 Watts + radio?
It's like using the wrong size screwdriver in a screw that's how I look at it.
Hey Mike, I have a Uniden Washington with a broken clarifier. Can you steer me in the right direction to purchase a new one. I believe it's 20k ohm.
DigiKey or any other electronics supplier should be able to provide it. Just measure the old control for dimensions. For a clarifier be sure it is a "linear" control and NOT "logarithmic ".
Advice Please!!
My husband has a cobra 200 gtl dx and it will not light up or turn on at all. He had it plugged in, keyed up once and blew some kind of fuse because afterwards, the display and everything quit. Any ideas or tips on what to do to fix this problem, Mike?
I don't understand why your videos tell what you did. They are mostly you telling a story.
Show people how it's done and where to test, how to scrape trace coatings, how to solder in the repair. We know you repair radio equipment. This is the 3rd video I watched and you just tell a story.
I have a 200 gtl DX that I need to have repaired. What is the contact info for your shop?
How do you remove green mask?
Kaitlyn Simpson
Scrape it off. I have a assortment of dental picks and scrapers made by GC Electronics. A small screwdriver works in a pinch.
MikesRadioRepair thanks
Does Mikes Radio Repair have a email address, I can contact him with?thanks
tonyvlx yes, we need to ask odd questions (about electronics)
@@tonyvlx It's Mikesradiorepair@gmail.com
Hey Mike, I've had my 200gtl for almost 15 years if not longer. How can I get a hold of you? Email?
Copper foil: basiccopper.com/6x6sa1bin115.html