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
Dismiss Notice
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.

Uniden Washington

Discussion in 'General CB Services Discussion' started by silverstreak, Feb 5, 2019.

  1. silverstreak

    silverstreak Active Member

    Joined:
    Jul 23, 2006
    Messages:
    74
    Likes Received:
    31
    Radio is all stock but has the normal clarifier mod done.no extra channels.The radio is one channel off.Your on 19 your really on 18 and so on.Tried to do a alignment and cant even get it close to normal channel.Anybody run into this before?And the only other thing wrong is the channel display some segments are out any help would be great the radio looks new.


     

  2. LeapFrog

    LeapFrog Wielding Hanlon's Razor

    Joined:
    Feb 15, 2016
    Messages:
    1,705
    Likes Received:
    859
    Have you just got this radio recently?
    If so, I'd have a look at this area:

    I had a Grant that had a super diode and choke added, and it was one channel off as you describe, I can't remember if the crystal frequency was changed also..

    A "super diode" may appear to be factory, but the one I found looked odd.
     
    #2 LeapFrog, Feb 5, 2019
    Last edited: Feb 5, 2019
  3. silverstreak

    silverstreak Active Member

    Joined:
    Jul 23, 2006
    Messages:
    74
    Likes Received:
    31
    It slides only a couple of kc not like a super. diode.Thanks for the reply
     
  4. LeapFrog

    LeapFrog Wielding Hanlon's Razor

    Joined:
    Feb 15, 2016
    Messages:
    1,705
    Likes Received:
    859
    No worries, good luck with it.
     
  5. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

    Joined:
    Apr 23, 2018
    Messages:
    4,834
    Likes Received:
    6,301
    Ah? Ok, Hey! - then if you are still "off" by one channel - the Clarifier mod you did - skipped a step.

    The output wire? Where does it go, from the Pot to the board - to bypass the RX/TX "feeder" issue?

    Because if you get power from the MB3756, and yet feed the Clarifier - does the RX frequency Track the TX frequency?

    If not, look for R187... R187Washington.jpg

    Remove it completely and APPLY (as in solder it) it ACROSS the Clarifier Source (from MB3756 chip) to Wiper (adjustable output)...

    Ok, with that done...did you BYPASS the little board the Clarifier used? Then you're missing R415 - it needs to be from RETURN of the Clarifier to ground - so go back and make sure R415 is in the return side of the Clarifier pot it pushed the varactor tuning voltage up to bring it to center slot. just reroute your Clarifier return back to that CB/PA switchboard where R415 is - you'll be fine.

    PA365g BoardTuningCenterning.jpg
     
    Shadetree Mechanic and LeapFrog like this.
  6. Robb

    Robb Yup

    Joined:
    Dec 18, 2008
    Messages:
    11,416
    Likes Received:
    3,478
    Are we talking about the 858pll or the 8719pll?
    They came with different pll's of early/late Washington's
     
  7. nomadradio

    nomadradio Analog Retentive

    Joined:
    Apr 3, 2005
    Messages:
    4,698
    Likes Received:
    6,209
    If it says "Uniden" on the front, and not "President", it will be the later radio with a 5-pin mike and the 8719 PLL.

    73
     
    Robb likes this.
  8. silverstreak

    silverstreak Active Member

    Joined:
    Jul 23, 2006
    Messages:
    74
    Likes Received:
    31
    I didnt do the clarifier mod so I will have to look to see what they did.Its the newer model 5 pin 8719 pll thanks to all that has replied
     
  9. nomadradio

    nomadradio Analog Retentive

    Joined:
    Apr 3, 2005
    Messages:
    4,698
    Likes Received:
    6,209
    If all you want is to make the clarifier follow your receive frequency when you transmit, it's fairly simple. Makes the radio a lot easier to use on sideband, when everyone can line up his transmit frequency with everybody else. It amounts to pulling one end of a diode, one end of a resistor, and one end of a wire. The end of the wire that gets pulled out gets soldered to the 8-Volt supply that feeds the PLL chip.

    I have a more-detailed version at work on the air-gapped computer. I can dig it out next time I'm there if you're interested.

    This radio is not a good one for 'stretching' the clarifier to tune a wider range of adjustment. If you do that, it makes the clarifier control touchy, and hard to tune a sideband signal just right.

    73
     
    tecnicoloco and Robb like this.
  10. silverstreak

    silverstreak Active Member

    Joined:
    Jul 23, 2006
    Messages:
    74
    Likes Received:
    31
    First thanks for the reply.I have been working alot so I havnt had time to look at the radio.Today I looked at it and it looks like they ran one wire to 8v and the other to ground.They didnt remove the resistor or diode.so either I will finish it or put it back to stock and see if its still one channel off.
     
  11. nomadradio

    nomadradio Analog Retentive

    Joined:
    Apr 3, 2005
    Messages:
    4,698
    Likes Received:
    6,209
    Well, okay.

    The procedure I have on file only applies to a stock radio.

    Leads me to wonder what change you see to the transmit frequency when you move the clarifier from one end to the other end.

    73
     
  12. NZ8N

    NZ8N Well-Known Member

    Joined:
    Dec 25, 2017
    Messages:
    249
    Likes Received:
    340
    Washington Clarifier.jpg
    8719 Washington Clarifier (single conversion chassis)

    - vs -

    148 Clarifier.jpg
    8719 148 Clarifier (double conversion chassis)

    There is an additional varactor diode circuit going to the emitter of the oscillator, this causes the double conversion 8719 chassis (148/2000/Grant/Madison) to have a wider range than the older single conversion 8719 chassis radios (140/142/Washington).
     
    tecnicoloco likes this.
  13. jon666

    jon666 Sr. Member

    Joined:
    Jan 24, 2006
    Messages:
    1,601
    Likes Received:
    793
    check if they put a 10kc jump on the switch
     
  14. dss56

    dss56 Active Member

    Joined:
    Sep 27, 2010
    Messages:
    220
    Likes Received:
    51
    Check pins16 and 17 on pll make sure no shorts or cut traces these 2 pins will give a 10kc jump in radio. Look to see if there are any wires connected to the 2 pins if so follow them and see if they go to the front of radio. Someone might of added a 10 kc jump switch.
     
    tecnicoloco likes this.

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!