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23 channel radio to 40 channel radio?

Discussion in 'CB and Export Equipment and Accessories' started by nat19, Jun 25, 2010.

  1. nat19

    nat19
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    I talked to 147 in Ontario Canada today on 37lsb. He said he was using a 23 channel midland radio with a modification to talk on channel 37. Is this possible? By the way he was hitting me with an S 7 and he said the radio was doing 12 watts.


     

  2. loosecannon

    loosecannon
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    sure.

    used to be quite a few kits sold to convert 23 channel radios to 40 channel radios back when the FCC added the new freqs.

    people also used to buy crystal switch boxes to add freqs above and below the CB band.

    the 23 channel radios used a process called crystal synthesis to achieve 23 channels with less than 23 crystals.

    for example, one set of transmit and receive crystals might be used for 4 consecutive channels.

    switch out those two crystals and you have 4 new channels.

    its pretty rare these days to talk to anyone using one of those old radios.
    he must've been an old timer. i always enjoy talking to the guys who have been doing this for 40 years now.
    they seem to have great stories.
    LC
     
  3. nat19

    nat19
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    Thanks I don't know much about 23 channel radios. Yeah its getting rare these days to find someone talking on the older 23 channel radios. This one sure did have a nice sound to it.
     
  4. Big Kahuna

    Big Kahuna
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    I had a Sidebander II hat was modified with a replacement rotatary switch and extra crystals to have all 40. Worked pretty well after the mod and almost looked stock.
     
  5. psycho

    psycho
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    I am pretty sure with a old 23 channel radio you have to use a different crystal for every extra frequency you want. 38 lsb is the most popular channel of the legal freqs to use.
     
  6. n8fgb

    n8fgb
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    Most used 10 cystals. 4 for 1-4, 6 for 4,8,12,16,20,23.
    Rich
     
  7. mechanic

    mechanic
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    :bdh: I was presented with a gift of an old Cobra 135 base! It had a switch on the bottom and I knew straight off it was modded for more channels! :whistle:
    Doing a little investigating, this switch, adds 23 more channels for a total of 46 and with it's open Voice Lock, makes all the in betweens and all RC misses!
    The old Cobra does a great job!

    Not every 23 channel mods this way, some need simple pin jumps on the PLL, some need extra or different crystals and there are channels kits. But these are getting rare so the mods are happening less.

    73 mechanic
     
  8. packrat

    packrat
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    I have a Green Robyn 23 tube base modified with a crystal switch box and 40 plus channels.
     
  9. Cityboy

    Cityboy
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    I have several friends running 23ch radios and I myself run one of the 7 that I own just for fun. I have a Midland 13-888b(made by Uniden for Midland) that is a great radio, I have a pristine and brand new Cobra 29A(made by Uniden for Cobra) and a spare Cobra 29A that has a custom cb faceplate by debsdecals that is all blacked out and I put blue leds in and looks awesome, I have Midland 13-866(made by Uniden) and great little radio, I have an Echo 99er(made by Sharp) that is almost in brand new condition except a couple of very light scratches on the bezel and has one of the clearest audio I have ever heard, and a Johnson Messenger 323 that works great, and a Regency CR-230(made by Uniden) that I lowered the dk to 2w and run a RM Italy 203p with and it dk with the amp on at 23-25w, and peaks at around 80w. I started out with cbs with my dad,a cb lover and ham operator over 40yrs ago and had my own base station 35years ago and I tinker and repair new and old radios and the one thing I can say with certainty is that the filtering and quality of the build and the unreal and clear audio on TX can not be beat on these radios. The only drawback is the low peak power but they have great modulation and can most times be heard over other newer peaked radios and especially the one I put the amp underneath, I can talk for miles and skip and they are so very quiet on the receive. Some of them do have crosschanneling receive problems but not too bad. I love these old radios and I try to get pristine ones, oh I also have a Mongoose 21(looks exactly like a Cobra 21 and made by Uniden of course) that is brand new in the box with all the instructions.
     
  10. Simbalage22

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    Loving old stuff..

    Yea, I didnt notice this thread.. I started one about my cobra 26.. you are right the sound quality on these old radios is amazing.. I had a midland 888 and she died, so I got a cobra 26.. Problem is... You guessed it.. Only 23 channels. Anyone with info on where to buy these replacement knobs to make it a 40 channel rig would be appreciative.. If I could get 40+ on this, I wouldnt have need for a newer radio... Then again being a 29/26 it may be a good idea to leave that one alone for collectors piece, and buy a regular 29..I know stock these radios do well....Have an old 1977 rocye too.. its 40 channels, and with mod clipped, and am turned up she screams with clear mod/sound :) I am getting back into the hobbie again, and am stuck on older stuff.. My base is ...you guessed it a 142 LOL
     
    #10 Simbalage22, Aug 7, 2010
    Last edited: Aug 7, 2010
    Kentucky buck likes this.

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