COBRA 29 MOSFET CONVERSION: CB Radio How to Install Easy Mod! The Radio Garage simple way.
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- Опубліковано 8 сер 2024
- The Radio Garage way of converting a cobra 29 or uniden 78 style cb radio chassis to a mosfet final transistor. Modulation is set after mod is performed using an oscilloscope.
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finally.... an intelligent and accurate presentation. great job!
Great video. At first thought I was like this guy is a hack but after watching I can clearly see he is not. That was very informative . I really like how you quickly explained how a good waveform looks too. Thanks much.
The Radio Garage,thanks alot for sharing your tip.I did my Uniden 78 Elite and had a low voltage @ the gate.The resistor from + @ C116,got my rig working properly.Really appreciate the video man.👍
Nice job nice work and thanks for taking the time to explain everything 73s and God bless from 112 Southern Illinois
I know this is a 2 yr olr video. However I'm just now seeing it. You have a great channel. You are one of 2 people I would love send my 29 classic and Realistic Navajo to. However I don't have the funding for things I need and want do to these 2 radios at this time.
Me 2
Thanks for a very instructive video and I would like to say that I share the same opinion about the mosfet that is not an upgrade just a replacement option
Thanks helped me decide what to do with my cobra radio.
Great stuff enjoy your work keep it up
7:28 Very nice RF waveform! Nobody shows the waveform and if they do, it's usually clipped to hell, obviously not the way true AM waveform should look. Yours is really nice, great job! 73's!
Thanks, im glad you can appreciate it. 73s
Excellent instructional video
Love your videos.
I am retired and bored.
Sooo i been trying to learn every luttle tip an trick an mod i can .
I will probably buy a scope soon i would like to learn to do clean mods.
I have a handful of radios with bad solder jionts and also picked up a anytone 5555n that i would rather have you look at it the guy i got it from messed it up a little.
Great step by step video.
Thanks, I hope it helps someone.
Nice job 👍
I wish that you were up here in the Toronto, (Canada) area.
You would have soooo much work from me! LOL
Wave Form looks Great!!! Good Clean 30+ Watts Ouput. Do a Cobra 29 Classic with a 2290 Transistor.
Thanks Greg. When the mosfet conversion is done the proper way you can get great results. Hmm a 2290 that would be interesting. Thanks for watching and have a Happy New year.
Cool videos
@The Radio Garage, Hey Buddy long time Subscriber here. I have an old Cobra 29 NW LTD Classic, (bought new in 2007). I had this Radio built, peaked & tuned shortly afterwardsThis lil Cobra PEP’s right at 50 watts. I’ve had it in a couple of Shops over the last 16 years getting minor things done, new Speaker installed and had Nitro Knobs installed, and have it cleaned thoroughly a few times. Every Shop I’ve had it in said it’s the only 29 they’ve ever seen that does 50 watts Cleanly. I haul Frack Sand so I Truck with the same Guys all the time and they all say that it’s a very Clean & Good Sounding Radio. The last Shop that did the Nitro Knob Install said that whomever did the Original Build/Tune did a really good job on it, and that he has never seen a 29 swing 50 cleanly. Is this possible with Mosfets? I know that’s what he did the build with because I’ve looked inside of it.
I am definitely not a Radio Builder. Just an Avid Radio Collector, User, Aficionado.
I have a Big Radio in my Truck now, and was thinking about putting this online for sale. Was curious as to what you think it should be worth, seeing as it is a Clean Talking 50 watt Radio with Talkback, Echo, and Nitro Knobs.
My gate voltage is 6. How do I lower it? Thank you for your help
What should the gate voltage be on a superstar ss9000 with dual irf520 finals. My ssb tx sounds distorted.
Radio new never touched. Was distorted out of box new from copper electronics from 2015. How to tell real irf520 fets from fake?
What is typically written on real irf520? Please advise, would love to clean up ssb tx.
Thanks, enjoy your videos.
I'd like to see how you install a good swing kit. and variable power. Thanks
So…. Love your work. How do I put a variable? Or do u have a link so send me in the right direction.
I have a question please.I have seen several of these modifications on the internet but none of the others show the 4.7k across R56 were the companion part goes.What does this do also I have seen some mods that don't put the 22pf cap where R55 was.What would happen if you didn't do this.I noticed it is done with the cobra 29 mosfet super tune but they still don't show the 4.7k across R56.PLMK and also they show putting a 68pf on the back of C59.If I just do it like you did will everything be okay.THANKS and sorry to bother you again.One mod I seen was just replace the final with mosfet,remove R55,R56,C61 then add then add the 470 ohm and diode companion part.Then add a 68pf on back of C59.Have ever tried that way and which way works best.Thanks
I would love to come to your shop and let you see my 29... On your test bench.... Definitely more than thirty peak....... And my limiters are still intact.......
Awesome 👍🏻
Great video, where did you learn CB radio alignment? I've had my tech certificate for a couple of years and ended up working in the "media" field building high voltage microphone pre-amplifiers. But I've always been into CBs. PM me if you want.
Useful, thanks. What type of capacitor did you replace the resistor (2min 45 sec) with please?
I believe it’s a 22 pico farad capacitor.
@@jamieweis74 Thanks very much for your reply. I appreciate it.
Would a irf530 or 540 work as well
Anyway to mod these with a 2N6045. Which is a RM Italy RM3 mosfet used in RM linear amps.
Unclear on bias circuit. What happened to the diode on the bottom side of the board?
What about newer am/fm ones
Can you setup one that will transmit on all 40 channels at one time ??
No I'm not that smart 🤣
@@TheRadioGarage ok iv seen them and heard about them ..
ok, you are changing something to a Mosfet, But to do what? it isn't clear? thanks
Can I use 1/4 watt resistors for the 470 ohm and 4.7k ?PLMK ASP THANKS
Yes 1/4 watt will be fine.
@@TheRadioGarage Thank you very much for the quick reply and great video.Happy July 4th.
how much you charge to do this to a cobra 25?
You can email me at theradiogarage@gmail.com with any questions. Thanks
How much to have this done ?
Can you post a parts list for the companion part?
The parts I used were a 1n914 diode, 470 ohm resistor and a 4.7k resistor. Put the 1n914 and the 470 ohm resistor in series into the r56 spot once the stock part is removed. Banded end of diode towards the front. Then just solder the 4.7k across the r56 leads on solder side. I tell you the parts and show how everything is installed in the video so be sure to watch the whole video. Thanks and be sure to subscribe if you want to see more CB related videos.
Thanks for the reply I watched it three times.i am just getting into the cb stuff and Learning the lingo on the electric stuff.
Ok no problem. Thanks for watching.
The Radio Garage on the bias circuit does the 1n914 or resistor go towards the front of the radio?
banded end of the diode towards the front of the radio
I watched the video 3 times and re checked every step. I’m getting 6 watts totals. What could I be overlooking
So you mean you have a 6 watt carrier or is that modulating?
The Radio Garage that’s all it will modulation.
Recheck your solder joints. Was the radio working well before? Also where did you get the mosfet from there are fakes going around.
The Radio Garage I unsoldered and re soldered. Yes radio was doing great. I get all mine from 6 star. Just making sure I didn’t overlook anything
Just curious whats your gate voltage?
Do you repair radio for customers if so can i get your address thanks
Change final in a cobra 29 Ltd
If a tech doesn't have the spectrum analyzer, they don't work on my radio
I agree 💯
so you just ship it to you for service? Tweak and peek.
All this info but no simple explanation on the reason to do this in the first place?
he did state at the end that this is a repair not an upgrade. It's cheaper than replacing the factory final... if you can even find the genuine transistor to do it with.