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CB Radios & Linear Amplifiers

bambambambambambam Member Posts: 4,818 ✭✭✭
edited February 2012 in General Discussion
Does anyone play around with these any more?

I'm taking a DC circuits class and was looking to find a diagram and parts list to make a linear amplifier.

There used to be pages and pages of how to on making your own and now I can't find anything unless you want to pay to see the plans.

Comments

  • john wjohn w Member Posts: 4,104
    edited November -1
    I have a schematic for a jb75 wawasse cb mobile dc amp if you want it. e-mail me and i will scan and send it to you
  • bambambambambambam Member Posts: 4,818 ✭✭✭
    edited November -1
    quote:Originally posted by john w
    I have a schematic for a jb75 wawasse cb mobile dc amp if you want it. e-mail me and i will scan and send it to you


    how many watts? 75?
  • john wjohn w Member Posts: 4,104
    edited November -1
    Yes 75 watts and it uses an 8417 tube and these linears will dead key about 80 watts with 4-5 watt drive and modulate up to about 125 watts clear and LOUD!. I used to shoot skip out of my car with one of these and they beat the solid state all to hell and back
  • kidthatsirishkidthatsirish Member Posts: 6,983 ✭✭✭
    edited November -1
    I would be intersted as well if you dont mind. I have a CB Radio, and I am very intersted in getting a Linear Amplifier for it. I would like to build one even more.
  • 76k2076k20 Member Posts: 643 ✭✭✭
    edited November -1
    I still have several CB's and a linear around, plus some old manuals. Not sure if the linear is for a CB or not, it is a tube-type.
  • LesWVaLesWVa Member Posts: 10,490 ✭✭
    edited November -1
    Look over Carl's Electronics if he has kits and plans to build just about anything electronic. Most of his stuff is offered at a decent price.

    Neighbors kid that plays around with electronic got the plans to build a 100 watt linear for a Walkie Tlkie from from Carl's.
  • armilitearmilite Member Posts: 35,490 ✭✭✭
    edited November -1
    Got a bunch of CB radios lying around if they still work I don't have a clue. I used to run a Browning SST which still does work with a Kriss Big Boomer 300 watt linear off a trick stick. Later mounted it to a Ringo. Boy the people in my apartment building used to go nuts when I was on. Even with in line TVI filters I still managed to come through on all there TV sets.[:D][:D]
  • fishkiller41fishkiller41 Member Posts: 50,608
    edited November -1
    quote:Originally posted by armilite
    Got a bunch of CB radios lying around if they still work I don't have a clue. I used to run a Browning SST which still does work with a Kriss Big Boomer 300 watt linear off a trick stick. Later mounted it to a Ringo. Boy the people in my apartment building used to go nuts when I was on. Even with in line TVI filters I still managed to come through on all there TV sets.[:D][:D]
    [:D][:D][:D][:D][:D][:D][:D]
    My Cousin has a 300W vac.tube type in his Jeep CJ5...
    He goes over on top of the river dike and talks to his "Skipper" buddies in OK.WV.and AZ.
    He'll get caught some day because he does it ALL THE TIME.
    He gets a kick out of just keyin the mike,and BLOWING EVERYONE within 200 miles,right off the channel...
  • john wjohn w Member Posts: 4,104
    edited November -1
    Back in the day i used to sell everything cb and ham related. My setup was a Yaesu ft101B with a drake L4B linear running off a 220 volt power supply at 1500 watts am and almost double that sideband. I was up high on a hill and had a set of pdl beams and boy could i shut anybody down if i wanted to.
    This was back when the fcc was very acctive so i got on and did my business and got off as quick as i could except whe skip was running. I remember shutting down the colored channels many times when they were cranking up their power to show what they had and i was more than 25 miles away!
    AHH the good old days.
  • john wjohn w Member Posts: 4,104
    edited November -1
    quote:Originally posted by armilite
    Got a bunch of CB radios lying around if they still work I don't have a clue. I used to run a Browning SST which still does work with a Kriss Big Boomer 300 watt linear off a trick stick. Later mounted it to a Ringo. Boy the people in my apartment building used to go nuts when I was on. Even with in line TVI filters I still managed to come through on all there TV sets.[:D][:D]


    The kriss big boomer was a dirty linear to anything tv or cb related ( bleed thru even with filters) but whe tuned properly they would do some talking. The trick on any tube linear is tune it up max on the plate and load and then dip the plate back and boy would they sound clean and crisp then.
  • armilitearmilite Member Posts: 35,490 ✭✭✭
    edited November -1
    quote:Originally posted by john w
    quote:Originally posted by armilite
    Got a bunch of CB radios lying around if they still work I don't have a clue. I used to run a Browning SST which still does work with a Kriss Big Boomer 300 watt linear off a trick stick. Later mounted it to a Ringo. Boy the people in my apartment building used to go nuts when I was on. Even with in line TVI filters I still managed to come through on all there TV sets.[:D][:D]


    The kriss big boomer was a dirty linear to anything tv or cb related ( bleed thru even with filters) but whe tuned properly they would do some talking. The trick on any tube linear is tune it up max on the plate and load and then dip the plate back and boy would they sound clean and crisp then.



    I couldn't agree with you more and for the life of me I don't have a clue as to what happened to it.
  • buckstarbuckstar Member Posts: 1,163 ✭✭✭✭✭
    edited November -1
  • bambambambambambam Member Posts: 4,818 ✭✭✭
    edited November -1
    I've got a Cobra 29LTD Chrome that I had tuned and peaked. It's got a 1.1 SW on almost every channel. It's mounted with a 6" magnet mount with 48" SS whip. For some reason I have better luck with magnets then hard mounts.

    I'll have to get the T&P undone if I want to use a linear on it.

    Anyone hear of the channel screen going bad because of dirt?

    Some of the lights on #8 don't light up and it looks like a #3.

    Called a local shop that I have not done business with and they said it needed a small hole drilled into LCD screen and spray contact cleaner.

    They said it was risky because it either fixed it or ruined it completely.
  • buckstarbuckstar Member Posts: 1,163 ✭✭✭✭✭
    edited November -1
    quote:Originally posted by bambambam
    I've got a Cobra 29LTD Chrome that I had tuned and peaked. It's got a 1.1 SW on almost every channel. It's mounted with a 6" magnet mount with 48" SS whip. For some reason I have better luck with magnets then hard mounts.

    I'll have to get the T&P undone if I want to use a linear on it.

    Anyone hear of the channel screen going bad because of dirt?

    Some of the lights on #8 don't light up and it looks like a #3.

    Called a local shop that I have not done business with and they said it needed a small hole drilled into LCD screen and spray contact cleaner.

    They said it was risky because it either fixed it or ruined it completely.


    This does not sound like a valid fix for an LED, LCD, or gas discharge display. There may be a communication error involved but The connections inside any of these displays are not user serviceable. The external connections may be solderable, cleanable, or replaceable though. If you have the type of radio that I'm seeing when searching for "cobra 29ltd" it is just a common 2 digit 7-segment LED display in there. It's a commodity item that you can find all over and replace yourself if you wish. If it turns out to be a bad driver chip then you won't likely get it repaired unless the chip is socketed and you can find a match for it. LED display driver chips are also a commodity item but there are many more variables to finding the correct one and some are house-brands that you won't find on the open market.
  • A J ChristA J Christ Member Posts: 7,534
    edited November -1
    quote:Originally posted by armilite
    Got a bunch of CB radios lying around if they still work I don't have a clue. I used to run a Browning SST which still does work with a Kriss Big Boomer 300 watt linear off a trick stick. Later mounted it to a Ringo. Boy the people in my apartment building used to go nuts when I was on. Even with in line TVI filters I still managed to come through on all there TV sets.[:D][:D]


    Pretty sure that they are illegal because of incidents like that.

    Run a linear and interfere with my electronics and we will have other problems.
  • jev1969jev1969 Member Posts: 2,691
    edited November -1
    I used to run a Conex 3300 with a D104 and a Cobra 250 linear for a mobile and a Cobra 2010 with a D104 lollipop and an 800 watt tube linear for a base. Farthest I ever reached out on skip was Birmingham England going east, San Francisco going west. Ahh the good old days.

    I still have all the old equipment and even pick up CB stuff when I see it at a garage sale. Figure it may come in handy during a SHTF scenario.
  • gunnut505gunnut505 Member Posts: 10,290
    edited November -1
    Copper Electronics still has "research" linears, as well as all that 10-meter stuff the truckdrivers use.
  • KnifecollectorKnifecollector Member Posts: 3,267 ✭✭✭
    edited November -1
    I have a Cobra 2000 with a Screaming Eagle Astatic power mike, along with a 6 tube Elkin. I used to shoot a lot of skip,I have some QSL cards from Jamacia. I haven't used it since they installed a local FM radio tower on the hill behind my house.
  • beneteaubeneteau Member Posts: 8,552 ✭✭✭
    edited November -1
    What you need is a Heathkit. However, I don't think Heathkit produces the kits for the "do-it-yourself" anymore. Several on eBay.
    0M9InwN.gif[
  • bambambambambambam Member Posts: 4,818 ✭✭✭
    edited November -1
    quote:Originally posted by gunnut505
    Copper Electronics still has "research" linears, as well as all that 10-meter stuff the truckdrivers use.


    The "10 meter" stuff kept coming up in my searches. What is that?
  • gunnut505gunnut505 Member Posts: 10,290
    edited November -1
    CB is "11 meter" and 10 meter is close enough that several frequencies overlap-funny channels and such.
    Also, 10 meter gives one the opportunity to run more power than the Citizens' Band.
  • TexasVetTexasVet Member Posts: 2,847 ✭✭✭✭✭
    edited November -1
    Years ago, we used to have a crystal and talk on "305".

    Understand it was a radio control frequency....somewhere, somebody's RC airplane may have taken a dive when I keyed that Browning Eagle with the tunable receiver and 500 watt linear........
  • bambambambambambam Member Posts: 4,818 ✭✭✭
    edited November -1
    quote:Originally posted by gunnut505
    CB is "11 meter" and 10 meter is close enough that several frequencies overlap-funny channels and such.
    Also, 10 meter gives one the opportunity to run more power than the Citizens' Band.


    So is 10 meter sideband? It sounds similar to me.
  • armilitearmilite Member Posts: 35,490 ✭✭✭
    edited November -1
    quote:Originally posted by A J Christ
    quote:Originally posted by armilite
    Got a bunch of CB radios lying around if they still work I don't have a clue. I used to run a Browning SST which still does work with a Kriss Big Boomer 300 watt linear off a trick stick. Later mounted it to a Ringo. Boy the people in my apartment building used to go nuts when I was on. Even with in line TVI filters I still managed to come through on all there TV sets.[:D][:D]


    Pretty sure that they are illegal because of incidents like that.

    Run a linear and interfere with my electronics and we will have other problems.


    They were illegal as all hell but that's why we ran them. I had a buddy that ran an Echo-Plex on his and it sounded awesome.
  • gunnut505gunnut505 Member Posts: 10,290
    edited November -1
    Nope, sideband is the part of the radio wave that exists a few hertz apart from the center of the frequency, on either "side" of the wave. That's why there are upper and lower sidebands on the radidio.
    You can run triple power legally on sideband as well (4 watts CB; 12 watts Peak Envelope Power on sideband).
    When you run a linear on SSB; you have to tune down the input or your transmissions will be all distorted. Much worse than the Donald Duck you hear from a non-SSB radio.
  • aw3olaw3ol Member Posts: 583 ✭✭✭✭
    edited November -1
    In the good ole days my time, I spent looking for the job to set me up for the life I was going to live and sorry to say, it didn't work out that way somehow, I went into retail lumber when I should of been in the ham radio biz finding the computer to be on the horizon. Needless to say when the thing did come out I wasn't into it because it cost to much only to draw fire from the the left on what a stereo costs? I've actually just sat in the bill this damn thing wanting to know who's running this place and where i'm going to find money for a lifetime of could you just buy it. The damn thing I just can't afford high end electronics and so I fiddle with radio's! Understand me that what's my goal in life is to escape this download and bye the bye... patronizing low-life

    [xx(]
  • woodshed87woodshed87 Member Posts: 23,478 ✭✭✭
    edited November -1
    WOW What was that[;)]quote:Originally posted by Flying Clay Disk
    quote:Originally posted by aw3ol
    In the good ole days my time, I spent looking for the job to set me up for the life I was going to live and sorry to say, it didn't work out that way somehow, I went into retail lumber when I should of been in the ham radio biz finding the computer to be on the horizon. Needless to say when the thing did come out I wasn't into it because it cost to much only to draw fire from the the left on what a stereo costs? I've actually just sat in the bill this damn thing wanting to know who's running this place and where i'm going to find money for a lifetime of could you just buy it. The damn thing I just can't afford high end electronics and so I fiddle with radio's! Understand me that what's my goal in life is to escape this download and bye the bye...

    [xx(]


    WOW!! I need some of that stuff! Errrr...well, maybe not!

    [:D]
  • john wjohn w Member Posts: 4,104
    edited November -1
    I had picked up a BIG ultrasonic parts cleaner and it had the power supply and 3 1000z tubes in it. I was converting it into a home linear but got sidetracked and never did finish it. It would have put out over 3,500 watts when done on am and double that on sideband. The 1000z tubes were rates at over 1000 watts each. The lower power supply weighed 150 lbs and had a HUGE transformer with 2 mercury vapor rectafier tubes. That thing would have shut down the bands for many miles around and tv sets and radios for sure!.
  • bambambambambambam Member Posts: 4,818 ✭✭✭
    edited November -1
    quote:Originally posted by buckstar
    http://www.cbcintl.com/images/LINRSCHM.GIF


    Do you know if that's for a CB or ham?

    Guess I should have stated I was looking for a mobile CB one.
  • buckstarbuckstar Member Posts: 1,163 ✭✭✭✭✭
    edited November -1
    quote:Originally posted by bambambam
    quote:Originally posted by buckstar
    http://www.cbcintl.com/images/LINRSCHM.GIF


    Do you know if that's for a CB or ham?

    Guess I should have stated I was looking for a mobile CB one.


    The website that it is from is dedicated to CB enthusiasts. If you are seriously considering building an amp though I suggest you do a more thorough search on the subject than I did. There is a very good chance that you will find one that is more suitable for you than the one I linked. Essentially I was responding to "looking to find a diagram and parts list to make a linear amplifier" by just throwing out the first qualifying schematic that I came across. I'm not stating that this one is the ideal solution or anything. I did it to demonstrate that you can find that stuff with a basic google search... and assumed that you would see a schematic and loose interest.

    Looking into how that site is using that diagram, it seems that they wish to sell you a book on how to build it. Your call. You can find additional schematics on other sites using "mrf454" as a search term. That is the power amp transistor used in the diagram I linked. Pulling out my set of Encyclopedia of Electronic Circuits there seems to be related schematics sprinkled throughout those too.
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