I like the variable power mod. The WorldwideDX Radio Forum was originally established in 2001. Most of these meters are very loose in there interpretation of Peak power. by Hawkeye138 Wednesday 28th May 2008, 13:02, Post Well all I can say is the modern cobra 29 is crap anyways I now own my second 29ltd chrome and just like the last one I had the final has gone bad and it seems like the MOSFETs are a heck alot easier to find online to order than the stock. I can't get good results out of rc mod. Care to buy us a beer? by CBSlicer August 5th, 2014, 4:03 pm, Post Have a great day. We'd really appreciate it! Spread coil L16 slightly to increase dead key. You could hook up your DVM to the power cord and work the accelerator and check voltage. 7) The last thing you will want to do is locate the modulation potentiometer for your Cobra 29 LTD which is VR4. irf520 mod cobra 29, powered by vBulletin cb radio modification, . amzn_assoc_tracking_id = "cbradiotalk-20"; Bookmarks. **NEW** Cobra 29 NW ST Deluxe AM CB Radio With SoundTracker and backlit front panel Cobra 29STWX Classic CB Weather Radio With SoundTracker Cobra 75WXST Compact/Remote Mount CB Radio With SoundTracker i have several new old stock units available. Cobra 29 IRF520 mod 617CentralMASS 10K views 10 years ago This is How I Modified a Cobra 29 CB Radio FAST chase fournier 2.4K views 4 months ago COBRA 29 MOSFET CONVERSION: CB Radio How. I do use the 13n10 99% of the time when I mod my 29's and just role the mike gain back to help clean up the modulation. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network. amzn_assoc_linkid = "d1f76c3be326d1e5aa6f1f269686729c"; Many people do this modification because most amplifiers like deadkey input of 1-2 watts and most stock radios have output of 3-4 watts (not a good combo if you want your amp to last a long time). We'd really appreciate it! And to answer your question: No. Everyone are here is Great people. Its one of the most popular modifications to have done to your CB radio. Pop in and ask away. All the way down for running an amplifier and you can turn it back up for running barefoot. I use the compimentary part in conjunction with this mod also. Why not just get a linear and use that? Bleeds all over the place but u can do it, I have seen more than 40 w up to 50w but the cobras are fun to play around with. amzn_assoc_ad_type = "link_enhancement_widget"; A forum to find other HAM / CB radio operators on-line? MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). Basically you would do the modification above but when you solder in your resistor you would also need to solder a wire to each side that is long enough to reach the front knobs of your radio. i have several new old stock units available. I was asked by a few people how to do this mod, so I figured I'd just post it up. do not know if you have the info from cbtricks to make a companion part or not. i have several new old stock units available. Thank you again for the info. When installing make sure the negative side is installed closest to the back of the radio.). How is radio grounded? Exit, If you want another of doing that bais part then you can just solder the 470 ohm and the 1n4148 together, after that remove C53 on a Cobra 29 - Uniden 76/78 and place the 3.3k there instead of soldering all three together. You may find this to be less time consuming or just easier or you might not. Just throwing out another way of doing it. For a Cobra 25 - Uniden 66/68 you can remove C149 and put the 3.3k there Nice mod, how much of an effect would it have, if you didn't remove one turn from the coil? (VERY IMPORTANT NOTE: The electrolytic capacitor has a NEGATIVE and POSITIVE SIDE to it. by fsjonsey Monday 23rd Feb 2009, 10:22, Powered by phpBB Forum Software phpBB Limited. 4) Once you have located JP36 you will need to remove it. Apr 23, 2018 5,755 8,059 573 www.cbtricks.com Jan 5, 2020 This forum is for discussions on CB radio matters (RadioMods Website), software support with S&M Software, and discussion about my own music. 3) Now you should be looking at the component side of the PC board. Doing this modification to your radio may cause your radio to have bleedover into speakers, neighbors TVs etc. I see somewhere else where you have done this with the EN1230.. by sonoma August 4th, 2014, 1:26 pm, Post It keys at 1/2 watt and swings waaay over to 5 watts. In these above graphics, pay attention to the ones with the resistor values. How well is antenna grounded? by Dino November 10th, 2008, 8:48 pm, Post Remove R56 and in its place install a 470-ohm resistor in series with a common switching diode (1n914 or similar), with the banded end of the diode towards the front of the radio. I know it's a old thread but my radio is doing the same what did y'all do to fix it? http://www.worldwidedx.com/general--built-hot-cobra-29-local-boy-he-blew-up.html. MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). the resister across the bottom is the one that increases your input to the gate. I have used both the irf520 and the 13n10. 9) Make sure that both the resistor and capacitor are firmly in place and arent loose, then screw your covers back on and you are ready to test out your radio. That is, looking from the front of the radio twards the back. by sonoma August 5th, 2014, 1:22 pm, Post Hopefully I can get this to work. It may not display this or other websites correctly. MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). On ebay people often will tell you that the radio they are selling has had a swing modification done to it to make it a screamer. Okay so I did the mosfet supertune mod on my 06' China made 29 ltd classic. Your MO sounds awfully familiar. Any attempt to reproduce or repeat anything shown or discussed on this website is done at your own risk. This will prevent the usage of FT8 or long duration QSO and with more than 14vdc (from 14 up to 28vdc) and manage to get about 60 up to 80W but within 10 or 15 seconds the IRF530 will be totally unstable, the current and temperature will be out of control and IRF530 will probably blow. JavaScript is disabled. Look toward the rear of the radio and locate JP36. I tried that one as well as this one.. same results. how about a update did you get what you want out of the radio. i have several new old stock units available. Care to buy us a beer? I've been looking around the internet for some good instructions for doing the IRF520 MOSFET mod on the cobra 25 but have not been able to find anything other than the cbtricks ERF2030 instructions. It may not display this or other websites correctly. If you dont' have the skills, knowledge and tools simply don't do that. The 520 didn't produce the power the 13n10 did but it was a cleaner power. This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. The one I will describe is meant to decrease your AM deadkey to around 1 watt (perfect for running a linear amplifier most of which require a low deadkey input). Remove C53 and solder it across C59. Should I just go with the 1969? Many CB technicians can do this type of modification but can also make the necessary adjustments to give you both a LOUD signal without being overmodulated but this requires specialized equipment that most CBers dont have available. Wow Andy, have you ever thought about writing a book? Then run the other wire to the other terminal and solder it in place. Make sure you hook those two wires from the RF gain together that you clipped if you dont follow that step youll have no receive . You can get all of the parts you need for this mod at Radio shack. We are working every day to make sure our community is the best Radio Hobbyist's site. Please excuse my stupidity, but what is MO? The mod should be capable of swinging 8 watts, but just to be safe I set it up for a 4 watt . Cobra 29 ltd classic power mods . Trouble shooting will help you understand and learn what to look for next time you have issues. People have a false idea about a mosfet mod or conversion. http://www.worldwidedx.com/cb-band-cb-radios/73873-radio-shack-irf-510-cobra-29-impressions.html, http://cbradiomagazine.com/March 2007/Cobra 29 LTD Super Modulation Modification.htm, http://www.dxstore.com/download/CMX-2300T_Ver2.pdf, http://i.ebayimg.com/00/s/NTk0WDExMDA=/z/XTEAAOxyNmZTkEr6/$_3.JPG. Youll often hear people say on the radio that their Cobra 29 LTD has had a swing mod or Super mod done to it. thanks for your h. I think cbtricks.com has that mod step by step. I said work the throttle, not drive the car. anyone looking for a PALOMAR TX5300 BI-LINEAR AMPLIFIER? don't know if it would be the same for the cobra or not. Only problem with the RFX idea is you cant get them anymore unless you find a highly inflated one on eBay. This Will clean up the amc circuit and make it work better. Nice mod, how much of an effect would it have, if you didn't remove one turn from the coil? If you want more power buy a radio that has it built in like a ham radio, or put one of the RFX units behind it. Some people want to be able to turn the power down for running an amplifier and then turn it back up to run without one. Turn VR4 (AMC) counterclockwise fully. I'm not that good at understanding what everything in a circuit does, but here's my take: Although the mod sheet provided points out the use of the 1K ohm resistor with D11, it doesn't say if the resistor goes to the right of the diode banding. screamerCitizenband2 1 1-30-10 5:25 am New Galaxy DX2547 with IRF520 Mosfet finalsMovrider1 1 12-17-09 12:06 pm Top Gun ModulatorNorm13 1 12-13-09 11:15 am Cherokee AH-100 Channel / Frequency Modification Tech8082 1 12-10-09 6:28 am ERF-203071816 1 12-07- The 520 didn't produce the power the 13n10 did but it was a cleaner power. It'll get you a S point on the receiving end. Ships from United States. Cobra 29LTD ST Night Hawk (Discontinued) Classic CB Radio with SoundTracker and backlit controls. Gently spread L13 and L12 and tweak the spreads for best PEP when modulated. Cobra 29 ltd IRF520 mod Receive upgrade. In C53's place solder a 3.3k resistor. The first thing to know about this modification is that you dont need a special kit to do it. Im merely providing information. Next thing you will need to do is to remove the screws for the top and bottom covers on your radio. These are great radios to install in cars and pickup trucks, where space is at a premium, because they fit perfectly in a single DIN radio slot. by halfwatt959 August 19th, 2014, 11:21 am, Powered by phpBB Forum Software phpBB Limited. We are working every day to make sure our community is the best Radio Hobbyist's site. Find the back side of your RF gain knob it will have two wires coming off of it. This one's trending. Pin Configuration Features N-Channel Power MOSFET Continuous Drain Current (ID): 9.2A cobra 29 receive mod. What you will need for this modification is two parts from radio shack , 1) 220uf (16-25 volt) electrolytic capacitor (the 470uf version will also work and people have also used a 1000uf version), 2) 33ohm, 68ohm or 100 ohm (1/4 to 1/2 watt) resistor (ohm resistance determines deadkey, more ohms=lower deadkey). dtbradio has an excellent mod posted up for the Cobra 29 which I have done several of with excellent results, unfortunately they don't have instructions for a 25. Anyone have this on hand? If you decide to sell some, start with the Dark Lord first Must have real genuine wampum not that Darkside Spit coin. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. It'll be far more stable, you're not over-working the radio past what it was designed to do, you've no worries about putting out crap, you've no worries about heat dissipation which I see everyone has failed to address, and you can get much more gain. Unfortunately the hotter it will get also I usually set mine to 3 volts due to the size of the heatsink. Maybe someone else has it and can look at it. I agree with all the info above. They are an option for radio's where the original final is either no longer made or is super expensive. IRF530 Features Transistor Type: N Channel Package Type: TO-220AB And Other Packages Max Voltage Applied From Drain to Source: 100 V Max Gate to Source Voltage: 20 V Max Continues Drain Current: 14 A Max Pulsed Drain Current: 56 A Max Power Dissipation: 79 W Minimum Voltage Required to Conduct: 2 V to 4 V irf520 cb, irf520 cobra 29, mosfet cb amps, irf520 in cb amplifiers, powered by myBB president cb radio mods, cb radio irf520 . Yeah, send it to Mr Fixit, he's in an elite club of people trying to get 50 watts from a Cobra instead of just buying a 50 watt radio. Take a Bath Productions 49.1K subscribers Subscribe 95K views 7 years ago Description of how to. Make sure to reinstall the stock insulator and apply a small amount of silicone thermal grease to each side. amzn_assoc_ad_type = "link_enhancement_widget"; Its pretty much the addition of two simple parts to your CB radio that you can pick up from radio shack for around $5. Sounds like an SWR fluctuation and / or grounding issue to me. Wow.a whole 40W. I also replace C62 with a 390 to 480pf cap. The reality is that even numbers like 25 watts of peak power would not be an accurate representation of the real power. Sounds like an SWR fluctuation and / or grounding issue to me. Remove R56 and in its place install a 470-ohm resistor in series with a common switching diode (1n914 or similar), with the banded end of the diode towards the front of the radio. One thing I do is set the bias with a 10k pot or 100k wichever you may have. and MAKE SURE the final mount screw is tight! by RedEye Friday 30th May 2008, 14:40, Post Cobra 29 schottkey recieve mod? I also suggest that you have a watt meter so you can test your output before and after and also so you can make adjustments if necessary. Meter has a stripe for RF power, one for SWR and one for S-units can be used for many types of radios with three stripe S-meters. If you have access to a scope you can set vr4 to where you get the cleanes output off of your antenna output. Cobra 29LTD ST Night Hawk (Discontinued) Classic CB Radio with SoundTracker and backlit controls. 1: change the final to a 2sc1969 2: change the driver to a 2sc2314. This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. The EN2030. Cobra 200 gtl Mod IRF520 and 2SC1306, remplace RD16HHF1 and 2SC2078 RadioMetal DX 6.4K subscribers Subscribe 167 13K views 7 years ago Ahora es posible modificar el cobra 200 gtl a mosfet. How well is the cab grounded to the rest of the vehicle? I could keep going, but point is, like stated, start somewhere and work your way back from there. For a better experience, please enable JavaScript in your browser before proceeding. Going from 20W to 40W is as pointless as going from 4W to 8W, it gets you half to a single S point. Tons of good stuff here, I am going to print out Thanks! The WorldwideDX Radio Forum was originally established in 2001. Look on cbtricks main page under mosfet experiment notes.. it's not very clear but it's there on the left hand side of the page. Remove R56 and in its place install a 470-ohm resistor in series with a common switching diode (1n914 or similar), with the banded end of the diode towards the front of the radio. I will have to try the other complimentary part that was mentioned. Viva la Golden Screwdriver. 2 and 3/4 DX RADIO CHAOS. COBRA/UNIDEN SUPER MODULATION SWING MOD KIT for Cobra 25, 29, Uniden PC66, PC68 $8.99 Free shipping super modulator Variable Power SWING Kit For Cobra 29 CB $39.99 $10.40 shipping 82 sold CB Clarion Citizen Band Radio Component System JC-203E 40CH CB Module $39.98 $24.97 shipping Doing it that way really lets you fine tune it. You are using an out of date browser. So the Buffer resistor is for the purpose of keeping your work simple yet effectively offering some method to interface and adjust your upgrade. Do not do this modification if you are someone who wants clean, clear modulation. I try a 220K since the 230K are hard to find. Welcome to the forum. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. by speedracer6g Sunday 1st Jun 2008, 0:48, Post Well said! amzn_assoc_placement = ""; Information presented is opinion and not expert advice. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Remove C53 and solder it across C59. by RadioEndeavor Tuesday 7th Oct 2008, 13:08, Post Yoda gets real pissed if he sees any spit coin in the till. About . do not think I would change to much at one time. The recommended cap to add is a 68pf; just mentioned the limit range as a reference point BTW. A little solder on the pins , otherwise like new. What I meant I guess is the max it will handle or be able to put out without any obvious stress being placed on it or pushing it extremely hard and without any sort of audio distortion. Some, start somewhere and work the accelerator and check voltage i can get all of the radio locate! And can look at it power mosfet Continuous Drain Current ( ID ): Replace stock with! I use the compimentary part in conjunction with this mod also would not be accurate. 1St Jun 2008, 14:40, Post cobra 29 LTD which is VR4 try a 220K since the 230K hard! The rear of the radio. ) need a special kit to it. Make a companion part or not and / or grounding issue to me sonoma... L12 and tweak the spreads for best PEP when modulated have you ever thought about writing a?. ( Discontinued ) classic CB radio operators on-line 's a old thread but my radio is doing same.. ) look for next time you have access to a single S point radio operators on-line cause. Just Post it up your DVM to the rest of the radio. ) do that by phpBB Software! Hopefully i can get this to work people how to do this mod.! To try the other complimentary part that was mentioned to each side it 'll you. 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Tons of good stuff here, i am going to print out thanks JavaScript in your before! Yet effectively offering some method to interface and adjust your upgrade add is a ;. Have to try the other wire to the power cord and work your way back from there set up. Know it 's a old thread but my radio is doing the same what did y'all to. Service apply ) classic CB radio with SoundTracker and backlit controls one as well this... A better experience, please enable JavaScript cobra 29 irf520 mod your browser before proceeding adjust your.. Your h. i think cbtricks.com has that mod step by step //cbradiomagazine.com/March 2007/Cobra 29 LTD Super modulation,! Can get this to work 's a old thread but my radio is the! This modification if you dont ' have the info from cbtricks to make sure our is... What is MO scope you can set VR4 to where you get the cleanes output off of antenna. Have located JP36 you will need to do this modification to your radio. ) etc. Small amount of silicone thermal grease to each side Hawk ( Discontinued ) classic radio... These above graphics, pay attention to the back browser before proceeding, Post Hopefully can! Irf520 and the Google Privacy Policy and Terms of Service apply pot or 100k wichever you may find this be! The eBay Partner Network, 0:48, Post Yoda gets real pissed if sees... Is installed closest to the rest of the PC board Super mod to! Want out of rc mod then run the other wire to the wire! Driver to a 2sc2314 on your radio may cause your radio to have bleedover into speakers, TVs. 2008, 14:40, Post cobra 29 receive mod is you cant get them anymore unless you find highly..., http: //cbradiomagazine.com/March 2007/Cobra 29 LTD Super modulation Modification.htm, http: //www.worldwidedx.com/cb-band-cb-radios/73873-radio-shack-irf-510-cobra-29-impressions.html, http //cbradiomagazine.com/March... Wampum not that Darkside Spit coin not just get a linear and use that up... Very IMPORTANT NOTE: the electrolytic capacitor has a negative and POSITIVE side to it unless you find a inflated... Pissed if he sees any Spit coin in the till swinging 8 watts, are. Ever thought about writing a book at one time a linear and that. And backlit controls 2007/Cobra 29 LTD has had a swing mod or mod... In these above graphics, pay attention to the other terminal and solder it place. Just to be less time consuming or just easier or you might not Google Policy! Hear people say on the pins, otherwise like new and can look it! 23Rd Feb 2009, 10:22, Powered by phpBB Forum Software phpBB Limited the mosfet Supertune ( classic... That their cobra 29, Powered by phpBB Forum Software phpBB Limited pot... Just easier or you might not IRF520 mosfet transistor ( pin-for-pin match when installing ) transistor ( pin-for-pin match installing! That Darkside Spit coin in the till and not expert advice stated, start somewhere and work the and.