1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
    Dismiss Notice

Uniden GrantXL-Philippine version

Discussion in 'General CB Services Discussion' started by Dmans, Jun 15, 2019.

  1. Dmans

    Dmans Well-Known Member

    Joined:
    Jan 22, 2017
    Messages:
    580
    Likes Received:
    474
    All,
    I have another project. This one is a Grant XL with an MB8719 PLL. The owner said it was working fine, made a strange noise through the speaker while receiving then receive was gone.
    I found this unit had been highly modified. I.e. 10 turn clarifier, extra channels on 2 of the front panel switches and a variable power potentiometer in place of the S/RF-SWR-Cal knob.
    I found the 10 turn potentiometer was bad. No resistance on either outside terminal to the wiper in any position. It was wired directly to 8vdc and grounded to the top of the 11.325 crystal. I replaced the 10k ohm 10 turn potentiometer with a new 20k single turn pot and added in the missing R174 and R175 resistors. It still has 8vdc on the wiper in TX and RX. The problem is after aligning the oscillator(s) the clarifier will slide up but will not slide down at all. Example: Aligning the AM oscillator at 27.185, the clarifier will slide up to approximately 27.245 but will not come back down to 27.185 much less slide below channel 19.
    In looking at the schematic (as found on CB tricks) I noticed what I think may be an error. If not, this may cause the problem I am experiencing.
    Below is the area of concern.
    D2C2C734-64CB-442A-AD36-8311458DC5E9.jpeg

    In comparison to the 148GTL schematic below;
    D288B706-70A7-4CDE-A698-04C0F01F29EB.jpeg

    I was leaning towards a bad varactor diode prior to see this strange routing of R174 and R175 on the Grant schematic.



    Any thoughts on this?

    73’s
    David
     
    Shadetree Mechanic likes this.

  2. IMD262

    IMD262 Well-Known Member

    Joined:
    Apr 26, 2005
    Messages:
    1,096
    Likes Received:
    268
    Why do people list the Uniden Grant XL radios as Philippines or Philly built???

    If I remember correctly they were all manufactured in the Philippines ... just saying.
     
    S&W357 and walterjn like this.
  3. Dmans

    Dmans Well-Known Member

    Joined:
    Jan 22, 2017
    Messages:
    580
    Likes Received:
    474
    Never mind. I figured it out.

    73's
    David
     
  4. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

    Joined:
    Oct 23, 2017
    Messages:
    2,049
    Likes Received:
    2,081
    What did you come up with?
     
    Robb likes this.
  5. Dmans

    Dmans Well-Known Member

    Joined:
    Jan 22, 2017
    Messages:
    580
    Likes Received:
    474
    Unbutchered the butchery that was related to installing the 10 turn clarifier. I'm not sure why people remove components to make the slide work greater than 3 or 4 channels but I suspect it is impressive to the customer that they charge to do it. Makes them feel like they are getting their money's worth I guess. It sure makes for a terribly unstable clarifier though and tends to eat components.
    I installed a resistor in the "R149" position. A 10k ohm part that was removed. It still ended up with more than 1 channel each way but this is one of those "freebies to help somebody out" deals". Last time I tried to make one as close to factory as possible for this owner, he was not real happy though the radio worked 100% and will probably last a long time now. Maybe because I took away something he paid for??(High dollar butchery!) I think he took it back to the butcher and had another round of butchery installed. Oh well, you can't protect people from themselves!
    This Grant has other problems I don't care for but my deal with this one is done. It will spontaneously combust soon from all of the butchery.

    73's
    David
     

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!