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Info for the GrantXL test points?

Discussion in 'General CB Services Discussion' started by Robb, Feb 23, 2011.

  1. Robb

    Robb Yup

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    Great radio . . .
    But . . . Tuning info is scarce,

    Any links to finding where the test points are for aligning this radio? I managed to find the first three test points. Even that wasn't so easy.

    Thanks in advance . . .


     
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  2. Moleculo

    Moleculo Administrator Staff Member

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    It's the same as the old Cobra 148GTL.
     
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  3. Robb

    Robb Yup

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    Thanks Mo . . .
    What I need is a link to the schematic for a GrantXL or Cobra 148GTL with the 5 pin mic. Or some link that describes the test points.

    Can't seem to find it . . . Even on CBTricks . . .
    Hmmmm.
     
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  4. Robb

    Robb Yup

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  5. Robb

    Robb Yup

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    What I need to find, is test point 1 - so that I can adjust the 3.6v on L19. Test point 5 too. But all of the test point locations will be greatly appreciated . . .

    (y)(y)(y)(y)(y)
     
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  6. tinman22

    tinman22 Member

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    tp7 and tp8 are just to the right of vr7 in my radio they are a yellow and purple wire globbed with clear silicone. they then go to a jumper plug towards the back left.

    according to this:
    4. Set the driver bias to 50 mA. (Power up the radio, put it
    in LSB or USB, set the mic gain at minimum, remove the wire
    from test point 8, insert a milliamp meter in series between
    the test point (which is positive) and the wire, key the mic,
    and adjust VR9 until the meter reads 50 mA.)

    5. Set the final bias to 100 mA. (Same instructions as in step
    4 except the test point is test point 7, and the adjustment is
    VR8).

    I found that here:
    Copper Talk: Uniden Grant NPC/RC mods and 12 volt to final mods


    tried working on this over the weekend ( thanks LC for the help)and seems my TPs are backwards. i'm going to look into this next weekend if I get a chance
     
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  7. loosecannon

    loosecannon break on through

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    i am going by the SAMS for the 8719 madison, so it should be pretty close, but some things may be different.

    TP1- is the output of L20, which connects to R106 and R107

    i cant find any TP5 in the alignment or in the schematic.
    what is the adjustment for?

    if you need others, post them and i will see which ones line up.
    LC
     
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  8. loosecannon

    loosecannon break on through

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    Robb, not sure the info i gave you was accurate.

    if found a schem for the Grant LT, which might be more helpful.
    it shows TP1 coming off of the VCO chip which would make more sense than the point i gave you previously.

    its hard to read, but i bet this schematic is what you need:

    http://www.cbtricks.com/radios/uniden/grant_lt/graphics/Grant_ltsch.gif

    LC
     
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  9. Robb

    Robb Yup

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    "TP1- is the output of L20, which connects to R106 and R107" is actually TP2 in the Grant XL. The 148GTL schematic shows the same thing as you described. Not the same. There is a difference from what I see on the Grant XL and the 148GTL. I have confirmed this by checking so far. I've done all of the synthesizer section part - except for the adjustment for L19.

    http://www.radiomods.co.nz/grantxlalignment.html

    "TP5" - is "R86":

    "Input of frequency counter to TP5 (at back near Q19).
    Ch. 19, USB - CT2
    Adjust for 7.8015MHz +5Hz, -0Hz.

    Ch. 19, LSB - L30
    Adjust for 7.7985MHz +0Hz, -5Hz.

    Ch. 19, AM, Transmit - L31
    Disconnect TP7 and TP8.
    Adjust for 7.8000MHz +5Hz.
    Reconnect TP7 and TP8."

    I hope to find some more info - Thanks LC!

    This is what I need the location for:

    "Input of DC meter to TP1.
    Ch. 40, AM

    Clarifier Midrange

    L19 Adjust for 3.6 volts."

    I think the info is in SAM's Vol. 221 . . .
     
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    Last edited: Feb 24, 2011
  10. Robb

    Robb Yup

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    Got it.

    TP1 is the top leg of "R20" in front of IC2

    TP2 is the top leg of R101 to the left of L22

    TP3 is the left leg of R107 in between L19 and L47

    TP5 is the top leg of R86 at the back near TR19
     
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  11. tecnicoloco

    tecnicoloco Active Member

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    Hello Robb:

    What is the board # PC-999,PC409,PC412 ?
     
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  12. Robb

    Robb Yup

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    PC-412 AH
     
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