8) Some people recommend adjusting L14 for maximum power, but in most cases after doing the modification your swing should be better than before and your radio much louder so trying to squeeze a couple of extra watts is not my recommendation. Wow.a whole 40W. Now you shouldnt have any wires running to your RF gain knob. by sonoma August 4th, 2014, 1:26 pm, Post I know it's a old thread but my radio is doing the same what did y'all do to fix it? The IRF520 is a Power Mosfet with 9.2A collector current and 100V breakdown voltage. Shipping: FreeStandard Shipping. . What type coax is in use? **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 Find the back side of your RF gain knob it will have two wires coming off of it. I'm referring to the 13N10FQP response curve compared to a IRF520 - the 13's turn on quicker, but IRF520 provides more linearity. 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. thank you for the info i was wondering how they were doing that without replacing driver its hard to find good info out there. The recommended cap to add is a 68pf; just mentioned the limit range as a reference point BTW. Hi guys. Remove C53 and solder it across C59. cap. Thanks SinStp for the explanation of the first step. by RedEye Friday 30th May 2008, 14:40, Post In C53's place solder a 3.3k resistor. Anyone have this on hand? and Handy Andy Do Your Research First, Then Decide. , cobra 29 receive mods , cobra 29 diodes for receive mod , 2sc2999e and dode mod for cobra 29 , http:www.cbjunkies.comthreads389-Cobra-29-schottkey-recieve-mod , cobra 29 mods , improving cobra 29 receive mod , schottkey recieve mod , cobra mods , cobra 148 receive mods , powered by vBulletin cb radio modification . :sneaky2: anyone looking for a PALOMAR TX5300 BI-LINEAR AMPLIFIER? Install the IRF520 Mosfet at Q25. Cobra 29 schottkey recieve mod? 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 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). 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 Bookmarks. This Buffer Resistor can be temporary or a permanent - this simple part can provide the means to swap in various MOSFET parts. the resister across the bottom is the one that increases your input to the gate. 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. 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. Welcome to the forum. Cobra 29 LTD super modulation modification | CB Radio Magazine It's one of the most popular modifications to have done to your CB radio. 1) Flip your radio upside down so the speaker is facing up. $4.50: Radio Cover Screws (Cabinet Screws) (Bag of 10) $2.50: Size: Fast-acting " x 1-1/4" glass . Here is a link to instructions for replacing the final . 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. 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 . How about the cap and resistor mod? 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 For a better experience, please enable JavaScript in your browser before proceeding. Yoda gets real pissed if he sees any spit coin in the till. thanks for your h. I think cbtricks.com has that mod step by step. 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. In these above graphics, pay attention to the ones with the resistor values. its a new 2012 cobra not sure if that makes a difference. Post JavaScript is disabled. **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 Turn VR4 (AMC) counterclockwise fully. amzn_assoc_linkid = "d1f76c3be326d1e5aa6f1f269686729c"; Remove C53 and solder it across C59. I use the compimentary part in conjunction with this mod also. Don't play with spreading the coils very much at all! It is very helpful. 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. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Replace C71 with a 33-47uf cap. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. You will see that the board has a lot of small labels on it in white lettering. I was able to successfully install an IRF520 MoSFET final in a Cobra 18WXSTII+. by CBSlicer August 4th, 2014, 1:33 pm, Post This is the far left leg looking at the front of the mosfet. In C53's place solder a 3.3k resistor. 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. The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. anyone looking for a PALOMAR TX5300 BI-LINEAR AMPLIFIER? Im not a CB technician so this information is being provided by an amateur unskilled individual. Is it because the driver is working, and the final isn't? by SinStp Wednesday 8th Oct 2008, 12:51, 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. In addition I make no guarantee to the validity of any of this info. 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. What gauge power wire? I attach one of the legs to the positive side of C116 and the other to the gate of your IRF520. Some resistors will give you a 1 watt deadkey, some will give you a 2 watt deadkey. Hi, next time go with EKL components for 2scxxxx replacements. 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- Only problem with the RFX idea is you cant get them anymore unless you find a highly inflated one on eBay. 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. Where exactly was the reading taken? Make sure to use the same terminals that the original RF gain wires used. Oh and also replace c71 with a 33uf 16v. 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). seems easier DON'T add a swing kit. Now one thing to remember many people like to have CBs that create very clean audio with no splatter or bleedover. I tried that one as well as this one.. same results. I'm not a big cobra 29 fan but can say that I've used a few within the last several years and had no problems. Use the link I gave you to that other thread and check everything out with a multimeter along the way. We are working every day to make sure our community is the best Radio Hobbyist's site. I put in the MOSFET final kit. Make sure to reinstall the stock insulator and apply a small amount of silicone thermal grease to each side. but when I check the voltage and it is low I change the resister to get it closer to 3.5 to 3.8 volts. Apr 23, 2018 5,755 8,059 573 www.cbtricks.com Jan 5, 2020 How is radio grounded? 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. 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. Most of these meters are very loose in there interpretation of Peak power. A pack of a couple costs $0.99 so you might as well buy a couple different values and that way you can experiment if you first choice doesnt work out. my galaxy 959 has a 520 for the driver as well as the final. 3: change the electrolytic capacitor by the audio IC (C42, 1000uf) to a 3300uf, 16v. 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. Have a great day. the voltage for the final is the main item that drives it. 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'm not talking about the max to push the final super hard. do not think I would change to much at one time. by Dino November 10th, 2008, 8:48 pm, Post 29/25 - IRF 520 Mosfet final Upgrade w/ bigdawgamps built companion part now one to... 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