New Cobra SE ekl mod

[iiirbob]

Hello I am a first time user and I need help.

I just did the new ekl mod on a cobra 29 se chrome with talk back.
I followed the exact instructions from ekl themselves and got very poor results. I ended up with a 1.5 dk and 15 to 18 watt swing. i had a better dk from stock and am considering changing it back. what could i have done wrong? has anyone else had problems with this. i have been tinkering with radios for thirty years and even though i am no pro i have done hundreds of peek and tunes but changing out the finals for better results has stumped me. please help me out. thanks Robert

[ouxly40]

Measure the bias and get back to us.

[ramblingman]

hello there.i was just reading you message.thought id put in my two cents worth.a while back i did the ekl mod on a cobra 148 gtl.i had the same results as you.it did better.as far as swing wattage.with the stock finals.i also followed the directions to a tee.i also have been working on cbs about 10 years.so i did everything right.i dont know if the transistors were duds are not......good luck with your radio

[kc8mob]

A cobra 148 already has a 2sc1969 final in it. So changing it out was a waist of time.

Other then that, those finals will functionally replace discontinued transistors. Doesn't mean they are superior and will yield better results, just that they will mount, operate and survive mobil RF applications.

My advice to everyone is to buy up all the old finals you can get your hands on.

[StrightClaw]

Iv'e had the same result with the newer Cobra 29s. However if i add the additional parts listed for the old 1969s i get great result useing the 2030.The older 29s dont seem to be a problem just drop it in.

[kc8mob]

Well all you guys need to keep in mind that efficiency of operation translates to output power.

All of that jazz that matches final up with driver has to do with this.

Impedance matching as well, which translates to efficiency.


Basically, efficiency is the key.

[YosemitySam]

I'm what they call a copy cat screwdriver hillbilly. So, don't just take my advise. I found that placing a 31pf to 110pf ceramic cap accross C62 improves the mod well for me. I had the same problem you had. And this increased deadkey from 1w to 5w and swing from 17w to 32watts. But there could be a fatel falt of some sort that I do not know about. I also put Vpower in it and I have had nothing but good reports. Wish I was a tech. But, I'm Just a dumb hillbilly Truckdriver, who would honestly would like to know more!!! 73's To all the Tech's who take time out of there busy schedules to help us in need!!!