Yaesu G-450XL Rotator Repair


Yaesu G-450XL Rotator Repair

In December of 2007, the rope support for the center element of my Cushcraft A3 broke, requiring me to climb the tower and bring the beam down for maintenance.  At the same time, at had been noticing that the rotator control was not indicating correctly, it was very erratic.  So I brought the rotator down for maintenance, as well.

The first step was to mark the side of the case, where the top and bottom of the clam shells connected together.  This would allow me to assemble it in the correct alignment when the time came.

Marked Case of Rotator

Next, I took the top cover off.  All of the bearings between the clam shells in the depression on the outside were safely stored.

Top Removed

A little inspection revealed what the problem was.  The center gear had broken away from the shaft it was pressed onto.  I tried re-pressing it back onto the shaft, but it was too worn out.  I found the phone number for parts in the back of my manual, and was surprised when I was actually able to order the part over the phone.  The red arrows show the two parts that should be stuck together.

Broken Gear

A few days later, the new gear was received in the mail, and installed into the rotor.  Note the liberal amount of grease.

New Gear

After reassembling the rotor, the controller said it was a little off of North

A Little Off

An adjustment on the rear of the controller brought it in line.


So now it lines up

Right On

Finally, the rotor controller provides an overlap indication to tell you that you have reached the end of rotation in that direction.  You actually have maybe another 15 degrees or so, for safety.  A pot adjustment inside the controller sets the point that the indicator comes on.

I set it here, and reinstalled the rotor and beam on the tower.

Migrated Comments:

21 Responses to “Yaesu G-450XL Rotator Repair”

  1. DANNY LAMB Says:

    I have a Yaesu G-450 XL rotor with the same problems you were having with the gears. I would appreciate if you would email me the phone number that you used to order the parts as I do not have a manual for the rotor anymore.
    Thanks for any help.
    Dan KC5CUC

  2. Randy Says:

    I have had a couple of inquiries about getting parts for this rotator, so I have added a link in my Documents area (see button at the top of the page) that has a U.S.A. source for parts. In addition, I have added a PDF copy of my Owner’s manual to the Documents page, so that you can find correct part numbers.
    Good luck and 73… de Randy WB0SMX

  3. Rory Says:

    Great description of the repair and photos as well! Thanks for taking the time to do so as I’m in the shopping stage for a rotator. BTW if you’re interested in my home build tower project that will accept whatever rotator I choose check out my photo logs link found on

    73 Rory

  4. Paul Says:

    Hi there,

    I just took apart my rotor (G650) looks the same as a G450.
    The brake got stuck, I took it apart but now I don’t know how it should be assembled. It is not very clear on the drawing how de coil spring should be place in respect to motor rinion gear and brake spring winder.

    Do you have any information? Maybe a detailed picture?

    Thank you.

    Best regards,
    73 paul de pe1lxx

  5. Randy WB0SMX Says:

    Sorry, Paul. The only pictures that I have are the ones in the post you were reading. I did not disassemble the rotor below the plate, so did not encounter the spring/brake assembly.
    Good luck in your repair… Randy WB0SMX

  6. Paul Says:

    Hi Randy,

    Thanks for your quick reply.
    Better asked then sorry, right?

    73, paul de pe1lxx

    Nice pictures on your site, also the old stuff.

  7. david Says:


    please help me to take apart my G650.

    F8CRS david

  8. Randy WB0SMX Says:

    Hi David,
    I’m not sure how much help I can be via the internet…
    I guess in general I would suggest:
    1. Find the service manual for the G-650 Rotator
    2. When disassembling, be sure to take LOTS of pictures, so you will know how it goes back together
    3. When you find a broken part, look up the part number in the service manual, and contact Vertex Standard for parts.
    (from the US, I used the address and phone in my post: http://www.wb0smx.net/?s=G450)
    4. Clean, lubricate and reassemble in the reverse order that you took it apart.

    Good luck with your project. Hope you get it working correctly.
    Thanks… Randy WB0SMX

  9. Alan, K7ACZ Says:

    Here is the factory manual for the G-450A (not G-450XL, I don’t know what the differences may be)


  10. Bart Says:

    Hi got problem with G450C as rotator don’t matching with controller east is before E then S is on 120then W is before S and the W just after S any help please

  11. wb0smx Says:

    Hello, Bart. I have a user manual with setup instructions and a schematic. Would that be helpful? From your initial comments, it seems that the ADJ potentiometer on the back of the controller might be maladjusted. There are probably several things that could cause the controller to fail to track with the rotator, including corroded/bad cable connections, a bad potentiometer in the rotator, or the ADJ potentiometer in the controller, to start with…

  12. Jim Says:

    Hi can anyone please tell me if the G450 A CONTROL BOX DIRECTION DIAL WILLwork without been connected to the antenna or radio please

  13. wb0smx Says:

    Jim, There is no need for an antenna or radio for the control box to work, but it must be connected to the matching rotator (the part that physically turns the antenna) in order to show correct position.
    – Randy WB0SMX

  14. Arnulf Says:

    I have a Yaesu G-450 A rotor with the same problems you were having with the gears. I would appreciate if you would email me the phone number/WEB-address that you used to order the parts from.
    Thanks for your help,
    La2hga, Arnulf

  15. wb0smx Says:

    It has been many years since I ordered these parts, but at the time, they were ordered from:

    Vertex Standard U.S.A.
    10900 Walker Street
    Cypress, CA 90630
    (714) 827-7600

    Good luck and 73…
    Randy WB0SMX

  16. N8tuw steve Says:

    Was having problems with my g450a.
    After taking it apart and a few pics.
    The problem was with the bowtie gear.
    That’s what I’ll call it. The small set screw had loosed up.
    Afterget to the part and tighting klutit up .
    Then put new grease and putting it back together.works great.be sure to mark the rotor. So it goes back together correct.

  17. Daniel Gabbamonte Says:

    Would like some info on my Yaesu G-450XL controller The lamp on the controller went out can you tell me bulbs to put in ….Thank you Danny k2oz@optonline.net

  18. wb0smx Says:

    I’m sorry, Daniel. The manual lists the lamp as Yaesu part # Q 1000068. I searched the internet, but find no reference to a substitute for that lamp number. Good luck in your search… Randy WB0SMX

  19. Raul Perez Says:

    I Got problem today with my 450xl.Run to east, but dont want to return to west, check all wires and recheck. Will the problem will be inside rotor? any gear or somrthing else?

  20. wb0smx Says:

    Hi Raul,
    There is a troubleshooting chart on page 6 of the rotator’s manual.
    You may download the manual here: YaesuG450.pdf
    There is also a link at the end of the post above.

    With the LEFT switch pressed, you should read about 30 volts AC between terminals 4 and 6 on the back of the controller. With the RIGHT switch pressed, you should read about 30 volts AC between terminals 5 and 6 on the back of the rotator.
    If these voltages are correct, then the problem is likely in the cable or the rotator itself. There’s not really any electronics in that path to speak of. Just wires off of the 30 volt winding of the transformer going through two switches, up the cable and into the windings of the motor of the rotator.

    If one of the voltages is missing, I would suspect a dirty or bad contact in the associated switch in the controller.

    It’s also possible that the rotator is turning, but the dial on the controller is not displaying correctly. That is a more difficult problem to troubleshoot, involving lots of electronics in the controller, and a few potentiometers and wiring in the rotator.
    Good luck in your troubleshooting.
    Randy WB0SMX


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