This is an attempt to make AM operate like SSB. It does nothing for distance or clarity, and in fact, may make the radio overmodulated. Take a good look at the scope during modulation. The wave form is flat topping. Not good. Leave the damn radio alone and use it the way it was intended to be used.
Never never never adjust the harmonic trap slug to get more power. All you did was increase power on the second harmonic and nothing for the fundemental frequncy. This mod was and is a failure if you want a propper working cb radio.
Your meter doesn't care about out of band wattage, it will measure them as well. Your waveform was clearly., clipped and pinched. Congratulations you just made a splatter box. One several channels and distorted audio.
I agree with you 100%. I don't understand why so many folks don't get that screwdrivering your cb radio does nothing but cause bleedover to adjacents channels. Leave your cb radio at 4w for AM & 12w for ssb. Use a good quality preamp mic & a good antenna. Besides when will folks understand that you need to use 4 x the rf power to achieve a 1 's' unit increase in signal. So all these guys that srewdriver their radios & try to squeeze 1 or 2 more watts is doing nothing but overload the final & shorten the life of that device. I don't know about the new Cobra cb's but the older Cobra 29ltd used either a 2SC2075 or 2SC2078 as the final transistor both of which have a maximum power dissipation of 10w. I don't see how a transistor that will technically nuke after that 10w maximum will give 20+ watts. It's a technical impossibility. I read all the time on various cb chat groups where guys claim their " tech" peaked & tuned their Cobra 29GTL & now it's doing 10w dead key & swinging to 30 or 40 watts. This is all smoke & mirrors & I'm gessing these guys are just not bright enough to get that it's impossible for the final transistor in that radio to produce that much rf output. You would need to redesign the entire rf amp section of the radio & use components that produce higher output as well as change a bunch of resistors, voltage regulator do a full transmitter alignment & possibly run a thicker wire to the final to supply more current as in order to get 40 w it might burn the tiny traces that were not made to handle larger current draw.
In theory 4 x to raise one s unit. But local to local just a little more might get you through the trees. I have seen 100 watt transmit to 500w get 2 s units on 7 mhz. CB seems to respond well to just small changes.
THAT EASY? wow- 1- sending blessing to your dad, 2- i hope you do some radios and different stuff to the CBs?.. that would be wicked cool! have a great day thanx for the video!
Hello sir... I have a question just to refresh my memory.. before i made a power variable resister using the squelch on front of the radio ...but i never did it like that... Can i run some wires from the capacitor straight to the bottom??? Instead of the one you used .. thank you for your time nice and simple 73
Helllo sir , I hope all is well , I hope that dad can recover faster and my prayers will be with y’all everyday ! I just found out I’m going to be a grandpa for a second one my first grandson is 3 ! WOW how time does travel
I would look into doing the diodes in series near the transformer to bring the deadkey down in a 21, 25, or 29 cobra radios. My PEP watts out was the same when you talk. The cap/resistor trick made my audio sound distorted for some reason. Maybe it was the cap I used? Ran into your channel today from your response video to Northbridge Fix. Cool to see you like CB radios. Take care and 73.
I noticed your audio was clipping on your O-scope , Is your AMC still intact ?? I was doing those Super Mods to run heaters back in 1980's and the 90's when I had my radio shop in South Louisiana , I was using 33uF 35 volt caps and 56 to 68 ohm resistors , I never cut the limiting diodes out of the radios , I always used my scope for clean modulation .....If you remember the roger beeps sounding like a fart sound then you just met the guy that helped invent it.....Strange story behind that modification ........
Awesome 👌 👏 👍 ...I Never used a Roger Beep . But I sure remember the Fart Roger beep ... I have a friend that's got a couple of radios with the fart sound Rodger beep , Still Broadcasting All Across the 48 states . Peace ✌️ Love 💚 and 18 Wheels and CBs to Ya Sir . Cleveland Tenn waivin a Hand ✋️
@@Al_Nunnery Yeah me and a friend started searching for a lower tone on the beeps and found the "Tone circuit" we strapped a mylar cap across it and had al low tone , so we experimented from there on the different tones and the timing of it.... A nano second to almost 3 seconds ..... ask your buddy where he got his fart at ... If he says Tiger Truck stop in South Louisiana , then I'm the guy that did it ... A lot of radio guys copied our unique beeps and made real good money on them also.... Now I did find out that Roger from Roger beep is making them with a built in fart that you can change with a DIP switch built onto the beep...Almost 80 bux for one not installed in your radio...
Now hook it up to a spectrum analyzer and see the splatter across the other frequencies that you did. More modulation does not equal more power on a direct frequency. It just increases the power to adjacent frequencies.
Great mod keep the hobby going. If you want to talk skip you need swing. Clean and clear is great but you won’t get out on skip much. You don’t need a lot of power to talk skip but loud modulation will work. Yes it’s distorted but don’t eat the mic and it will sound good.
I actually tried that on four radios. Didn’t see much of a significant change. Maybe a Watt or 2 in talk power and that was it. Actually not worth playing around with it past a normal power wire upgrade, caps, finals and a Peek & tune. Just Sayin 😶
From what dad was explaining to me, the mod is to lower the carrier so the modulation is louder and packs more of a punch when talking. It's not necessarily to push more power.
so how hot does that pot get? i find 1-2 watt resistors heat up with the driver current getting pulled through it, i can only imagine that is on the verge of melting if you get long-winded
Believe it or not, I've seen these pots last many years. I was just talking to a customer the other day, my dad had did this modification to his Radio 13 years ago and it's still running great. Cobras are pretty resilient as well as just all around great radios.
@@chasefournier have you ever keyed down and put your finger on that pot? i've fixed a bunch of rigs over the years that had a 69ohm or 100 ohm under the jp36 spot, but even a 2w resistor would heat up. what I do here is make a NPC module with a TIP120 darlington, which handles the current, and the pot controls that between the collector and base. with this method heat is more a non-issue, and the darlington gets warm, but i tend to bolt it to the case. it's a few more parts than just a resistor and cap, but its more durable, and looks better on the scope as long as the limiter pot is set right
i live out in country side, been useing cbs senes the 70s , now iam retird now, i miss talking on the radio, my last one was stolen out of car four years ago,
If you see an Easter egg.. 😏 lmk
The modulated carrier looked pinched off to me.
The audio was flat.topping after the mode
This is an attempt to make AM operate like SSB. It does nothing for distance or clarity, and in fact, may make the radio overmodulated. Take a good look at the scope during modulation. The wave form is flat topping. Not good. Leave the damn radio alone and use it the way it was intended to be used.
Never never never adjust the harmonic trap slug to get more power. All you did was increase power on the second harmonic and nothing for the fundemental frequncy. This mod was and is a failure if you want a propper working cb radio.
Will this work ona cobra 29 ltd nightwatch?
Thank you for being humble and understanding without being condescending.
Great video Brother.👍
Can you do a video on how to connect an oscilloscope to a cb step by step no one has done it
Your meter doesn't care about out of band wattage, it will measure them as well. Your waveform was clearly., clipped and pinched. Congratulations you just made a splatter box. One several channels and distorted audio.
I agree with you 100%. I don't understand why so many folks don't get that screwdrivering your cb radio does nothing but cause bleedover to adjacents channels. Leave your cb radio at 4w for AM & 12w for ssb. Use a good quality preamp mic & a good antenna. Besides when will folks understand that you need to use 4 x the rf power to achieve a 1 's' unit increase in signal. So all these guys that srewdriver their radios & try to squeeze 1 or 2 more watts is doing nothing but overload the final & shorten the life of that device. I don't know about the new Cobra cb's but the older Cobra 29ltd used either a 2SC2075 or 2SC2078 as the final transistor both of which have a maximum power dissipation of 10w. I don't see how a transistor that will technically nuke after that 10w maximum will give 20+ watts. It's a technical impossibility. I read all the time on various cb chat groups where guys claim their " tech" peaked & tuned their Cobra 29GTL & now it's doing 10w dead key & swinging to 30 or 40 watts. This is all smoke & mirrors & I'm gessing these guys are just not bright enough to get that it's impossible for the final transistor in that radio to produce that much rf output. You would need to redesign the entire rf amp section of the radio & use components that produce higher output as well as change a bunch of resistors, voltage regulator do a full transmitter alignment & possibly run a thicker wire to the final to supply more current as in order to get 40 w it might burn the tiny traces that were not made to handle larger current draw.
In theory 4 x to raise one s unit. But local to local just a little more might get you through the trees. I have seen 100 watt transmit to 500w get 2 s units on 7 mhz. CB seems to respond well to just small changes.
THAT EASY? wow- 1- sending blessing to your dad, 2- i hope you do some radios and different stuff to the CBs?.. that would be wicked cool! have a great day thanx for the video!
Thank you! We will have to see in the future 😁
Another great video Chase , keep up the great work 😁
SNAKE OIL BS. now its a splatterbox
Eh to each their own.
Hello sir... I have a question just to refresh my memory.. before i made a power variable resister using the squelch on front of the radio ...but i never did it like that... Can i run some wires from the capacitor straight to the bottom??? Instead of the one you used .. thank you for your time nice and simple 73
It looks like it's flat topping and clipping
Helllo sir , I hope all is well , I hope that dad can recover faster and my prayers will be with y’all everyday ! I just found out I’m going to be a grandpa for a second one my first grandson is 3 ! WOW how time does travel
Thanks Jose! & Congratulations buddy!! 🎉🥳
One could use an cheap rtl-sdr usb dongle to watch the channel splatter in real-time, on a waterfall display.
I would look into doing the diodes in series near the transformer to bring the deadkey down in a 21, 25, or 29 cobra radios. My PEP watts out was the same when you talk. The cap/resistor trick made my audio sound distorted for some reason. Maybe it was the cap I used? Ran into your channel today from your response video to Northbridge Fix. Cool to see you like CB radios. Take care and 73.
I noticed your audio was clipping on your O-scope , Is your AMC still intact ?? I was doing those Super Mods to run heaters back in 1980's and the 90's when I had my radio shop in South Louisiana , I was using 33uF 35 volt caps and 56 to 68 ohm resistors , I never cut the limiting diodes out of the radios , I always used my scope for clean modulation .....If you remember the roger beeps sounding like a fart sound then you just met the guy that helped invent it.....Strange story behind that modification ........
Yeah, we never clipped the mod limiter. And that is a hilarious story
Awesome 👌 👏 👍 ...I Never used a Roger Beep . But I sure remember the Fart Roger beep ... I have a friend that's got a couple of radios with the fart sound Rodger beep , Still Broadcasting All Across the 48 states . Peace ✌️ Love 💚 and 18 Wheels and CBs to Ya Sir . Cleveland Tenn waivin a Hand ✋️
@@Al_Nunnery Yeah me and a friend started searching for a lower tone on the beeps and found the "Tone circuit" we strapped a mylar cap across it and had al low tone , so we experimented from there on the different tones and the timing of it.... A nano second to almost 3 seconds ..... ask your buddy where he got his fart at ... If he says Tiger Truck stop in South Louisiana , then I'm the guy that did it ... A lot of radio guys copied our unique beeps and made real good money on them also.... Now I did find out that Roger from Roger beep is making them with a built in fart that you can change with a DIP switch built onto the beep...Almost 80 bux for one not installed in your radio...
I don't use an amp.... Can I use this Mod on my cobra 29 Ltd 29 classic anyway?...
Yes you can.
aah yes a super mod..dont you still need to align the transmitter as well ?
yes
HAHAHAHAHAHAHAH HAHAHAHAHHAHAHHA.
Now hook it up to a spectrum analyzer and see the splatter across the other frequencies that you did. More modulation does not equal more power on a direct frequency. It just increases the power to adjacent frequencies.
I’d like to see this
Buy an cheap rtl-sdr usb dongle to watch channel splatter on the waterfall in real-time. @@neshamayne2212
is it me or was that radio KIPLING to beat the band that last klip when the amplutude modulation wave form was shown on the phone
Yep it was major distortion.
Right???
I dont think I would be letting this guy work on my radio, but I would ask his directions on how to get to the nearest doughnut shop.
🤣💀
His wallet is as big as he is 😇
obviously, he knows more than you, so go back to licking windows and buckle your helmet another notch, your short bus is waiting for ya.
How much current is going through that small resistor?
That would actually be a fun project to try. In the future maybe I will investigate.
Do you live in NYC, if yes you got 1 client here
We are in Michigan! If you'd like to mail it in, we can do it for you! Goto our website and setup a Mail-in request! cfmicrorepairs.info
Great mod keep the hobby going. If you want to talk skip you need swing. Clean and clear is great but you won’t get out on skip much. You don’t need a lot of power to talk skip but loud modulation will work. Yes it’s distorted but don’t eat the mic and it will sound good.
17-21 watts.. damn now you can talk to the world BWAHAHAHA
Now i have looked like we Said :) oscilloskop Philips is great tool :)
Do you work on a brownie Golden eagle Mark III?
I actually tried that on four radios. Didn’t see much of a significant change. Maybe a Watt or 2 in talk power and that was it. Actually not worth playing around with it past a normal power wire upgrade, caps, finals and a Peek & tune. Just Sayin 😶
From what dad was explaining to me, the mod is to lower the carrier so the modulation is louder and packs more of a punch when talking. It's not necessarily to push more power.
Hi, Great video! What is the wattage of the variable resistor? Thank you
Thank you! It's ½ watt
More info on cb 's great video
How do you connect an oscilloscope to a cb to get a signal?
Ask anybody but that idiot.
Good info!!!👍
Good evening.
Good work .
so how hot does that pot get? i find 1-2 watt resistors heat up with the driver current getting pulled through it, i can only imagine that is on the verge of melting if you get long-winded
Believe it or not, I've seen these pots last many years. I was just talking to a customer the other day, my dad had did this modification to his Radio 13 years ago and it's still running great. Cobras are pretty resilient as well as just all around great radios.
@@chasefournier have you ever keyed down and put your finger on that pot? i've fixed a bunch of rigs over the years that had a 69ohm or 100 ohm under the jp36 spot, but even a 2w resistor would heat up. what I do here is make a NPC module with a TIP120 darlington, which handles the current, and the pot controls that between the collector and base. with this method heat is more a non-issue, and the darlington gets warm, but i tend to bolt it to the case. it's a few more parts than just a resistor and cap, but its more durable, and looks better on the scope as long as the limiter pot is set right
cool
How many was k was that variable?
0-200 ohm
The transistorized controlled carrier is much better than this mod.
In the great word of Mike's Repair.. Boxcars..
i live out in country side, been useing cbs senes the 70s , now iam retird now, i miss talking on the radio, my last one was stolen out of car four years ago,
How many days will the radio run for before it goes boom
500 years
@chasefournier >>> 👍👍