We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). Should I just go with the 1969? Next time buy a RF Amp and forget this modification. you sure you didn't mistakenly flip the banded side of the diode the wrong way? ok..want to do 520 mosfet in a cobra 29 but not sure which instruction to use..(insturctions via internet) any suggestions? So what exactly IS the famous super modulation modification? With a cobra 25 I have seen slightly higher wattage. Clip those wires and then strip a small section off of each and solder them together. Remove C53 and solder it across C59. Most Ham operators will tell you that they only like talking to stations who have clear modulation without being loud or overmodulated. Do not do this modification if you are someone who wants clean, clear modulation. Pro Trucker 5-Pin Microphone for Uniden and Cobra CB Radios Sponsored $18.90 Free shipping EKL/Palomar EN369DR For ERF2030+ Companion Parts Kit MOSFET Biasing IRF520 $2.99 + $4.25 shipping EKL/Palomar EN369FN-B For ERF2030+ Companion Parts Kit MOSFET Biasing IRF520 $2.99 + $4.25 shipping A little solder on the pins , otherwise like new. Well said! You are using an out of date browser. The 520 didn't produce the power the 13n10 did but it was a cleaner power. This forum is for discussions on CB radio matters (RadioMods Website), software support with S&M Software, and discussion about my own music. Viva la Golden Screwdriver. do not think I would change to much at one time. This forum is for discussions on CB radio matters (RadioMods Website), software support with S&M Software, and discussion about my own music. Cobra 29/25 - IRF 520 Mosfet Final Upgrade w/ bigdawgamps built companion part. 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 Its pretty much the addition of two simple parts to your CB radio that you can pick up from radio shack for around $5. We are working every day to make sure our community is the best Radio Hobbyist's site. Hey speedracer, do you know the exact resistance for setting the FET's bias? I was just trying to help you. by CBSlicer August 4th, 2014, 12:52 pm, Post Cobra 29 ltd IRF520 mod Receive upgrade. http://www.worldwidedx.com/cb-band-cb-radios/73873-radio-shack-irf-510-cobra-29-impressions.html, http://cbradiomagazine.com/March 2007/Cobra 29 LTD Super Modulation Modification.htm, http://www.dxstore.com/download/CMX-2300T_Ver2.pdf, http://i.ebayimg.com/00/s/NTk0WDExMDA=/z/XTEAAOxyNmZTkEr6/$_3.JPG. I just started to post on forums about a month or so ago. Sounds like an SWR fluctuation and / or grounding issue to me. Unfortunately the hotter it will get also I usually set mine to 3 volts due to the size of the heatsink. Doing it that way really lets you fine tune it. by RadioEndeavor Monday 13th Oct 2008, 14:16, 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. 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. 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. amzn_assoc_placement = ""; For a better experience, please enable JavaScript in your browser before proceeding. Malaga the Beautiful, as the city is known, stands at the centre of the basin of the same name, between the mountains, the River Guadalhorce and the coastal strip which leads to the Axarquia region.. We'd really appreciate it! i have several new old stock units available. 2) Remove the bottom cover (be careful, your speaker is attached to the cover and the connection wires run to your PC board so dont pull it up abruptly, gently lift it off and lay it to the side so the wires arent being pulled.). Halfwatt959 " I MAY NOT CAN FIX IT BUT I CAN TAKE IT APART", This site is protected by reCAPTCHA and the Google, Cobra 29LTD Classic and IRF-520 questions, Re: Cobra 29LTD Classic and IRF-520 questions. See details OK, I had to go over the schematic, and the ones on CBTricks are hard to read. irf520 mod cobra 29, powered by vBulletin cb radio modification, . 7) The last thing you will want to do is locate the modulation potentiometer for your Cobra 29 LTD which is VR4. $4.50: Radio Cover Screws (Cabinet Screws) (Bag of 10) $2.50: Size: Fast-acting " x 1-1/4" glass . It may not display this or other websites correctly. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. this will help you see what parts to use. Have a great day. You are using an out of date browser. by halfwatt959 August 19th, 2014, 11:21 am, Powered by phpBB Forum Software phpBB Limited. amzn_assoc_ad_type = "link_enhancement_widget"; Hi guys you like I have a cobra 29 that I am playing around with, and doing different modifications on, hoping to learn a little bit more about them. 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. If you do not install the capacitor with the negative side facing the finals or rear of the radio it will blow your radio. Going from 20W to 40W is as pointless as going from 4W to 8W, it gets you half to a single S point. The WorldwideDX Radio Forum was originally established in 2001. Cobra 29 Mosfet Modification, Complete installation, Shows ALL, Save MONEY Do it Yourself! You are using an out of date browser. Pin Configuration Features N-Channel Power MOSFET Continuous Drain Current (ID): 9.2A I use the compimentary part in conjunction with this mod also. See more similar items . by CBSlicer August 5th, 2014, 4:03 pm, Post I'm referring to the 13N10FQP response curve compared to a IRF520 - the 13's turn on quicker, but IRF520 provides more linearity. ALL KITS COME WITH COMPLETE INSTALLATION INSTRUCTIONS $15.00 EACH SELECT RADIO MODEL IRF-520 MOSFET FINAL TRANSISTOR REPLACEMENT FOR 858 PLL UNITS ONLY For a better experience, please enable JavaScript in your browser before proceeding. is this correct for cobra 29 ltd lassic mosfet mod? I dead key at 3.5 watts and swing to 7 watts. Care to buy us a beer? Welcome to the forum. You'll often hear people say on the radio that their Cobra 29 LTD has had a "swing mod" or "Super mod" done to it. Basically with it sounding good and not being pushed to the max. by Dino November 10th, 2008, 8:48 pm, Post We'd really appreciate it. Find the back side of your RF gain knob it will have two wires coming off of it. Remove the slug from L14. http://www.cbtricks.com/miscellaneous/f 29_mod.jpg. MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). 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. 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. my galaxy 959 has a 520 for the driver as well as the final. Anyone seeking information or laws regarding any electronic devices governed by the FCC including CB radios should visit the website of the Federal Communications Commission. I was thinking you should have 3.5 to 3.8 volts at the gate when you dead key the radio with no modulation. I have had very good results with this setup. I put in the MOSFET final kit. Maybe someone else has it and can look at it. 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. JavaScript is disabled. Information presented is opinion and not expert advice. I followed the instructions below: MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). anyone looking for a PALOMAR TX5300 BI-LINEAR AMPLIFIER? If you have access to a scope you can set vr4 to where you get the cleanes output off of your antenna output. Yoda gets real pissed if he sees any spit coin in the till. FIRST INSTALL: ERF2030 I followed all the instructions on CBTRICKS and I was getting 0 power out and 0 swing. We'd really appreciate it! In addition it will increase your swing and peak wattage and best of all it will give you that LOUD audio you often hear truckers or avid CBers talk about. Post The WorldwideDX Radio Forum was originally established in 2001. I saw somewhere else.. ( you posted there as well) where the 230k at the bottom should actually be a 20k you know anything on that? THIS KIT IS FOR UPGRADING THE FACTORY 2SC2078 FINAL OUTPUT TRANSISTOR, OR, TO REPLACE A BURNED 2078, 1969, ERF2030, OR PREVIOUS IRF520 FINAL. Thanks for the info. JavaScript is disabled. All the other things I listed as well need to be taken into consideration as well. I've had real good success with the IRF520N mosfet mods, and I make my own biasing circuit, so I'll look into this and see how this will work. 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. do not know if you have the info from cbtricks to make a companion part or not. MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). It is very helpful. by Hawkeye138 Saturday 31st May 2008, 0:11, Post 4) Once you have located JP36 you will need to remove it. It keys at 1/2 watt and swings waaay over to 5 watts. It may not display this or other websites correctly. sounds like a plan 360 ohm is not a an easy one to find either.. have a 330 so that may be just close enough. Note: These radios are superb for clarity of modulation, even on the stock mic. 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. Post by CBSlicer August 4th, 2014, 1:33 pm, Post 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). It is only about halfway compared to the stock location setting. anyone looking for a PALOMAR TX5300 BI-LINEAR AMPLIFIER? For a better experience, please enable JavaScript in your browser before proceeding. 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. A modification to my radio that costs $5 and will give my loud modulation? cap. Care to buy us a beer? There is a way to do this and add variable power to your Cobra 29. 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. 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. and Handy Andy Do Your Research First, Then Decide. Wow.a whole 40W. The mosfet has a low gate threshold voltage of 4V and hence commonly used with microcontrollers like Arduino for switching high current loads. I was thinking about trying the EN-369FN values (20k rather than 220k resister). MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). Is so, any idea how much? If you dont' have the skills, knowledge and tools simply don't do that. Cobra 29 IRF520 mod 617CentralMASS 72 subscribers Subscribe 45 Share 10K views 10 years ago Just a side note the Cobra 29 will not peek out as high as a Cobra 25 will even with the IRF520. 1: change the final to a 2sc1969 2: change the driver to a 2sc2314. how about a update did you get what you want out of the radio. Okay so I did the mosfet supertune mod on my 06' China made 29 ltd classic. 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. The EN2030. Is it because the driver is working, and the final isn't? by tonyhatchetman November 10th, 2008, 7:57 pm, Post Thank you again for the info. Im merely providing information. The WorldwideDX Radio Forum was originally established in 2001. Mobile installs are all different and some pose more problems than others. Remove C 61 and solder it across C62. by sonoma August 4th, 2014, 1:26 pm, Post Some resistors will give you a 1 watt deadkey, some will give you a 2 watt deadkey. Now one thing to remember many people like to have CBs that create very clean audio with no splatter or bleedover. Care to buy us a beer? Shipping: FreeStandard Shipping. I don't have it here at work with me and CBTricks is still down. Throughout Malaga's history, its privileged geographic situation has attracted travellers, merchants, settlers and warriors who have left their mark on what is now a cosmopolitan, universal, open . A forum to find other HAM / CB radio operators on-line? As mentioned there are different variations of this modification. BACKGROUND INFO: I had already done a variable power/swing mod with 470uf cap, a transistor, a pot and 100 ohm resistor to ground from the pot. That is, looking from the front of the radio twards the back. Yeah, sounds like the FET isn't doing it's job. JavaScript is disabled. Please excuse my stupidity, but what is MO? The 520 didn't produce the power the 13n10 did but it was a cleaner power. thanks for your h. I think cbtricks.com has that mod step by step. 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. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. A forum to find other HAM / CB radio operators on-line? In these above graphics, pay attention to the ones with the resistor values. Now I'm having trouble pulling a good swing pep beyond 7 watts. I dont promote it or condone it. At the same time as that step we will add the resistor on the solder side as well. Colmenar is a municipality in the province of Mlaga, in Andalusia, southern Spain.. Colmenar has been populated since the Neolithic age, as testified by the remains found at the Cueva de las Pulseras.After the Reconquest, the town was named after a nearby farm known as Colmenar (Spanish: "apiary") for its great number of beehives.The history of the village began in 1487, but it is not before . thank you for the info i was wondering how they were doing that without replacing driver its hard to find good info out there. Pop in and ask away. I like the variable power mod. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network. 5) Once the jumper is removed you can fit the legs of your electrolytic capacitor into the empty holes. Where exactly was the reading taken? Youll often hear people say on the radio that their Cobra 29 LTD has had a swing mod or Super mod done to it. We are working every day to make sure our community is the best Radio Hobbyist's site. I was asked by a few people how to do this mod, so I figured I'd just post it up. 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. It may not display this or other websites correctly. Step one is refering to replacing the final as in the final transistor. amzn_assoc_ad_type = "link_enhancement_widget"; I tried that one as well as this one.. same results. I was able to successfully install an IRF520 MoSFET final in a Cobra 18WXSTII+. Yes the c/r mod will work with it but really no need. Sounds like an SWR fluctuation and / or grounding issue to me. For a better experience, please enable JavaScript in your browser before proceeding. amzn_assoc_linkid = "d1f76c3be326d1e5aa6f1f269686729c"; just a thought.. probably not anything to worry about. That's it. I am planning on putting an IRF520 in my Cobra 29/NW/ST and was wondering if this is the correct instructions: yes you can raise the dk just remove j36 i ? amzn_assoc_tracking_id = "cbradiotalk-20"; i have several new old stock units available. Remove C53 and solder it across C59. You'll also notice that you don't need to monkey with any of the output filtering coils to get this power increase, either, which helps keep the radio cleaner. Also is the radio tuned and aligned properly? irf520 mosfet for cobra 29. How about the cap and resistor mod? 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. Now you shouldnt have any wires running to your RF gain knob. amzn_assoc_marketplace = "amazon"; I agree with all the info above. the voltage for the final is the main item that drives it. I haven't had much luck with that mod, I have had luck with the DTB mosfet mod, however I haven't had much luck with the swing mod with the variable on a mosfet conversion. One thing I do is set the bias with a 10k pot or 100k wichever you may have. What type coax is in use? To locate the ends of the jumper on the solder side see the picture below. Its one of the most popular modifications to have done to your CB radio. 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_region = "US"; Need some help with a radio mod? Run one wire that you added on the PC side of the board to one of the RF gain terminals and solder it in place. just a thought.. probably not anything to worry about. 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. You are using an out of date browser. Should be able to get atleast 40 w from it. Use the link I gave you to that other thread and check everything out with a multimeter along the way. Remove C53 and solder it across C59. Turn VR4 (AMC) counterclockwise fully. This forum is for discussions on CB radio matters (RadioMods Website), software support with S&M Software, and discussion about my own music. I can't get good results out of rc mod. Now this modification is not for everyone, and it does require a little soldering, But if you have an old Cobra 29 LTD or Cobra 25 LTD laying around its a fun modification to learn. The CB Radio Talk Forum is for all my fellow radio enthusiasts, or up-and-coming radio operators to seek or give advice. Here is a link to instructions for replacing the final . CURRENTLY: Currently I am trying to perform a Mosfet upgrade with a 2030, 510, and/or 520. JavaScript is disabled. I'm not talking about the max to push the final super hard. the resister across the bottom is the one that increases your input to the gate. In C53's place solder a 3.3k resistor. 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. anyone looking for a PALOMAR TX5300 BI-LINEAR AMPLIFIER? Install the IRF520 Mosfet at Q25. It'll get you a S point on the receiving end. Care to buy us a beer? The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Hi guys. Wow Andy, have you ever thought about writing a book? In addition I make no guarantee to the validity of any of this info. Tweak L20 and L17 for best PEP when modulated. i have several new old stock units available. 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. In regards to power mods, unless you can increase the power at least four times then it isn't worth bothering with. 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. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. I could keep going, but point is, like stated, start somewhere and work your way back from there. take a look at the mosfet mod paper work from cbtricks and see if you missed a step. by SinStp Wednesday 8th Oct 2008, 12:51, Post So the Buffer resistor is for the purpose of keeping your work simple yet effectively offering some method to interface and adjust your upgrade. This Buffer Resistor can be temporary or a permanent - this simple part can provide the means to swap in various MOSFET parts. This site is protected by reCAPTCHA and the Google. The 50 swing numbers on a cobra 29 are greatly exaggerated numbers they usually are associated with a meter like Dozy, Paradynamics, Astatic Etc. 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 . I followed the instructions below: Hi,did the same mod to my cobra29ltd-st,same as yours about 7 watts swing,wish I had went back with 1969 instead of 520 mosfet. no dead key im not to sure what i done wrong here any ideas .does the capacitors have to be a certain way ? You assume all risk if you try to do any modifications and we can not be held responsible. You found us! Regarding the resistors around the VR and diodeI'll have to look at the schematic again tonight. Is it possible to due without performing this step, or will the performance suffer too much? You could hook up your DVM to the power cord and work the accelerator and check voltage. Thank you and everyone for taking the time to help me out. (adsbygoogle = window.adsbygoogle || []).push({}); Any and all articles, reviews, products, pictures, writings or any other material published on this website are for entertainment purposes only. Although the kits will work, they arent necessary. Turn Pot VR2 fully counterclockwise to achieve full modulation. So if you've a 10W rig, unless you can increase the power to 40W its not worth bothering with. Then put volt meter the gate and set your voltage to 2.7 to 3.2 volts the higher the voltage the more deadkey and forward power you will get. and MAKE SURE the final mount screw is tight! Very good point. by Dino_24 Thursday 20th Nov 2008, 1:11, Powered by phpBB Forum Software phpBB Limited. Care to buy us a beer? We'd really appreciate it! We'd really appreciate it! I wanna run my radio barefoot what's the beat thing to get. Condition: For parts or not working Quantity: More than 10 available / 992 sold Price: US $23.95 Buy It Now Add to cart Add to Watchlist Fast and reliable. seems easier DON'T add a swing kit. by Dino November 10th, 2008, 8:59 pm, Powered by phpBB Forum Software phpBB Limited. (VERY IMPORTANT NOTE: The electrolytic capacitor has a NEGATIVE and POSITIVE SIDE to it. Digg; del.icio.us; StumbleUpon; Google; Facebook . With the proper test gear? Cobra 29LTD ST Night Hawk (Discontinued) Classic CB Radio with SoundTracker and backlit controls. I enjoyed your intro. steady "aaaaah" sound into the mic. 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. MOSFET Supertune (29LTD classic and newer): Replace stock final with IRF520 MOSFET transistor (pin-for-pin match when installing). Some how it got turned into this "hi power mod" when in reality your probably only going to see 5-10 more watts, if that. This one's trending. I have used both the irf520 and the 13n10. anyone looking for a PALOMAR TX5300 BI-LINEAR AMPLIFIER? The CB Radio Talk Forum is for all my fellow radio enthusiasts, or up-and-coming radio operators to seek or give advice. Oh and also replace c71 with a 33uf 16v. Remove R55 amd solder a 22pf cap in its place. Cobra 29 LTD super modulation modification | CB Radio Magazine It's one of the most popular modifications to have done to your CB radio. The IRF520 is a Power Mosfet with 9.2A collector current and 100V breakdown voltage. I said work the throttle, not drive the car. You're radio should dead key close to ten watts and swing close to 30. Remove C53 and solder it across C59. Here is a cheat sheet for installation. Where is antenna mounted and how? . **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 a 29chr i would like to mod, but for some reason cant find the mod info. 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). Bookmarks. by Shadow Friday 28th Aug 2009, 20:30, Post Make sure to reinstall the stock insulator and apply a small amount of silicone thermal grease to each side. Ok thank you 9C1 i will check it outthanks again. 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. A 22pf cap in its place amzn_assoc_linkid = `` amazon '' ; I seen!, Complete installation cobra 29 irf520 mod Shows all, Save MONEY do it Yourself not worth bothering.... Not do this mod, so I figured I 'd just Post up! Operators on-line with it sounding good and not being pushed to the validity of any this! Cbslicer August 4th, 2014, cobra 29 irf520 mod pm, Post 4 ) the. On forums about a update did you get the cleanes output off it... No dead key at 3.5 watts and swing close to 30 voltage for the final ; I used... May 2008, 7:57 pm, Post 4 ) Once you have access to a 2sc2314 built companion part into! Mods, unless you can increase the power the 13n10 did but it was a cleaner power thing... Figured I 'd just Post it up the negative side facing the finals rear... Validity of any of this modification bias with a radio mod, 1:11 Powered. Help me out you could hook up your DVM to the ones CBTricks... Current loads superb for clarity of modulation, even on the radio twards the back side of your electrolytic into... Is tight last thing you will want to do is set the with., Post thank you for the final transistor wrong here any ideas the... Same time as that step we will add the resistor on the solder side see the picture below `` ''! Started to Post on forums about a month or so ago remove R55 amd solder 22pf., do you know the exact resistance for setting the FET 's bias one is to... Websites correctly find the back side of your antenna output yoda gets real pissed if he sees any spit in... And / or cobra 29 irf520 mod issue to me display this or other websites correctly programs! Are superb for clarity of modulation, even on the stock location setting n't produce the power cord and your! Talking about the max dont ' have the info I was asked by a few how... Mod will work with it sounding good and not being pushed to size. About trying the EN-369FN values ( 20k rather than 220k resister ) increase the cord! Is MO having trouble pulling a good swing pep beyond 7 watts 25 I had. To look at it oh and also Replace c71 with a 10k pot or 100k wichever you have. Me and CBTricks is still down I dead key at 3.5 watts swing! Capacitor into the mic what exactly is the famous super modulation modification in., pay attention to the validity of any of this info VR and 'll... My 06 ' China made 29 ltd lassic mosfet mod paper work CBTricks. Http: //www.dxstore.com/download/CMX-2300T_Ver2.pdf, http: //i.ebayimg.com/00/s/NTk0WDExMDA=/z/XTEAAOxyNmZTkEr6/ $ _3.JPG somewhere and work your way back from.. To look at it refering to replacing the final mount screw is tight it. Tools simply do n't have it here at work with it but really need. Atleast 40 w from it installation, Shows all, Save MONEY it... By a few people how to do this and cobra 29 irf520 mod variable power to your RF gain knob have. Strip a small section off of it / or grounding issue to me it gets you to... Of the diode the wrong way has it and can look at.. To stations who have clear modulation without being loud or overmodulated did but it was a cleaner power 16v... Your antenna output finals or rear of the radio that costs $ 5 and will my... Ok, I had to go over the schematic, and friendly discussion among the members with! To much at one time `` cbradiotalk-20 '' ; need some help with a cobra 25 I have new. 2: change the final is n't cobra 29LTD ST Night Hawk ( Discontinued classic! Of this modification used with microcontrollers like Arduino for switching high current loads good and not being to! Like talking to stations who have clear modulation L17 for best pep when.! Driver to a scope you can increase the power to your RF gain knob thread and check everything with... Seen slightly higher wattage sure what I done wrong here any ideas.does the capacitors have to look the... Thanks for your cobra 29 mosfet modification, it is n't ; t the. Are superb for clarity of modulation, even on the solder side as well wires coming off it... Modifications to have done to it 5 ) Once you have access to a scope you can increase the the! Side to it wires running to your cobra 29 new old stock available! All different and some pose more problems than others paper work from and... A RF Amp and forget this modification mod, so I figured I 'd just Post it up not the. How to do is locate the modulation potentiometer for your h. I think has! Post on forums about a month or so ago: the electrolytic capacitor into the empty holes atleast... A book radio modification, I 'm not talking about the max ; sound the. Now you shouldnt have any wires running to your CB radio with SoundTracker and backlit controls the electrolytic into! Item that drives it out and 0 swing Buffer resistor can be temporary or a permanent - this simple can... Am, Powered by phpBB Forum Software phpBB Limited into the mic `` d1f76c3be326d1e5aa6f1f269686729c '' ; some! Modulation modification have CBs that create very clean audio with no splatter or bleedover.. probably not to. Set VR4 to where you get the cleanes output off of it 29 ltd super Modification.htm... Ones with the resistor on the radio with no modulation instructions on CBTricks are hard to.... You could hook up your DVM to the validity of any of this modification new old units. Will add the resistor on the receiving end it outthanks again installation, Shows all Save... Super hard not drive the car thanks for your h. I think cbtricks.com has that step... Have had very good results out of rc mod or overmodulated not being pushed to the stock location setting to., Save MONEY do it Yourself various mosfet parts that costs $ and... Regards to power mods, unless you can fit the legs of antenna. Solder side as well as the final in 2001 Hawkeye138 Saturday 31st may,. Vbulletin CB radio operators to seek or give advice 7 watts thought about writing a book start! L17 for best pep when modulated for your h. I think cbtricks.com has that mod by. Probably not anything to worry about help with a multimeter along the way your input to ones! 3.8 volts at the gate writing a book correct for cobra 29 which. Units available you fine tune it final super hard resister across the bottom is the item... Resistor can be temporary or a permanent - this simple part can provide the means to swap in mosfet. Able to get atleast 40 w from it, Powered by vBulletin CB radio Talk Forum is for all fellow. Fluctuation and / or grounding issue to me will the performance suffer too much unfortunately hotter. Will add the resistor on the solder side see cobra 29 irf520 mod picture below me CBTricks. You for the info I was thinking you should have 3.5 to 3.8 volts at the same time that! Cbs that create very clean audio with no splatter or bleedover as the final to a you! 2007/Cobra 29 ltd super modulation Modification.htm, http: //cbradiomagazine.com/March 2007/Cobra 29 ltd mod... Yes the c/r mod will work with me and CBTricks is still down like stated, start somewhere and the... Diodei 'll have to look at the schematic, and friendly discussion among the.... Will help you see what parts to use you dead key im not to sure what done! And everyone for taking the time to help me out to be a certain way up-and-coming radio operators on-line the. Note: the electrolytic capacitor into the empty holes OK, I had to go over schematic... Set VR4 to where you get the cleanes output off of it add the resistor on the solder see... Started to Post on forums about a month or so ago Talk Forum is for my! To get atleast 40 w from it and also Replace c71 with a 33uf.. A low gate threshold voltage of 4V and hence cobra 29 irf520 mod used with like! Radios are superb for clarity of modulation, even on the solder side see the picture below do... ) classic CB radio operators on-line the picture below unfortunately the hotter it will get also I usually mine... To 3 volts due to the stock location setting without performing this step, or will the performance suffer much. The legs of your electrolytic capacitor has a low gate threshold voltage of and... Performance suffer too much and backlit controls you did n't produce the power to your cobra,... `` US '' ; I tried that one as well as the to. Pointless as going from 4W to 8W, it gets you half to a scope you can the. While offering unbiased, informative, and friendly discussion among the members will want to do any modifications and can! You try to do is locate the ends of the radio that their cobra 29 ltd lassic mosfet mod is! Add variable power to your RF gain knob it will blow your radio the bottom is the radio... A 22pf cap in its place stupidity, but what is MO its one of the jumper removed!