Cobra 148 gtl dx 11 meters to 10 meters conversion

Discussion in 'Radio Circuits, Repair & Performance' started by M0MTS, Jun 5, 2007.

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  1. M0MTS

    M0MTS Ham Member QRZ Page

    I have an old cobra 148 gtl dx,which i would like to convert to 10 meters (I am now a full license holder) :
  2. W4GLM

    W4GLM Ham Member QRZ Page

  3. M0MTS

    M0MTS Ham Member QRZ Page

    Hi Mac
    thanks for your help,is the 148gtl the same as my 148 gtl dx,I`m not sure.Only got it out of the loft the other day,not been used for years.It has the PB010 chasis.and an If Frequency of 10.695
  4. W4GLM

    W4GLM Ham Member QRZ Page

    Cant really speak to the 148GTLDX.

    I do know the 148GTL was made for the US market and

    was only a legal 40 channel unit. very easy to move to 10

    meters. After conversion, you may need to align the recv.\

    But will probably work just fine, especially as the band


    G.L. with the mod.....Mac
  5. AB8RU

    AB8RU Ham Member QRZ Page

    Banks of 10 & 37 Mhz. Oscillator XTALS with one not in sequence that was RC channels.

    grab a calc key is 37 Mhz. the RCI was set up with alot of Synth. XTALS for 10M.

    also FREQ Counter , and signal generators are sugguested to tune up and a Schematic or a SAMS Photofact Manual.

    BTW also a dummy load.
  6. N1JBS

    N1JBS Ham Member QRZ Page

    Seeing that this is a little old..... Since when does a PLL radio use banks of 37 mhz xtals?

    The loop xtal you want to change is 11.3258mhz
    I have started a page on my freewebs site on cb to 10 meter conversions:

    The cobra 148 gtl dx does not use the same mixing as the regular 148 gtl.
  7. WA7KKP

    WA7KKP Ham Member QRZ Page

    [​IMG]? Are you thinking this is an older 23 channel crystalplexer?

    This radio is a synthesized -- and easily modified for out-of-band operation, per the other posts.

    That is why they are quite popular in the CB world, being a 15+ year old design.

    Gary WA7KKP
  8. K5GHS

    K5GHS Ham Member QRZ Page

    You could go on ebay, overprice it, get some sucker to buy it, and get another radio too [​IMG]

  9. GW0VCK

    GW0VCK Ham Member QRZ Page

    The PB010 version uses 15.000mhz Xtal (soldered to the 3 tuning coils at the front end of the set, below the 10.695 xtal), in some cases it might use the 15.450mhz Xtal (but very rare), Just calculate (by adding .450) for the next Xtal upwards to get you into the 10mtr band.

    For eg: if your set uses the 15.000mhz add .450 + .450 which will give you obviously 15.900mhz, The set then should start on "low band" will be 27.865 - 28.305 upwards, if your set has already had the diode matrix mod done to it then it will go right up into 10 but you WILL need to relock the VCO and retune RX&TX stages too, Where you can get Xtals from i don't know.

    It would also be a good idea to retune freq with coarse in centre position to .000 rather than .005

    Hope this helps.
  10. W7CMG

    W7CMG Ham Member QRZ Page

    What is a "full license holder"?  
    What country is that callsign from? (just curious - no info on QRZ)
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