Johnson Viking Ranger Slipping VFO Dial

[N4JOY]

The VFO dial of my Johnson Viking Ranger has begun to slip -- so bad that the dial can no longer be adjusted.  I assume I will need to completely open the dreaded "fort knox" VFO compartment and remove the front panel to remove/access the shaft.  Can anyone provide some advice or suggestions that might help?  Does this problem suggest that the drive is stripped beyond repair?  Are suitable replacement parts available?

Thank you!

Chris, N4JOY   

[WQ9E]

Chris,

It is most likely the ball reduction drive causing the slippage, otherwise it could be a loose set screw in the coupler.  I think I have pulled and re-lubed the reduction drive in all of my VFO equipped Johnson gear (Ranger 1 & 2, a couple of Valiants, and a Viking 500).  If your tuning felt rough before the slipping started it is probably the reduction drive but you can easily check to see if it is the coupler just by watching it while tuning once you take the case off; if so just tighten the offending coupler set screw. 

If it is the reduction drive, unless it is terribly worn you can fix it through cleaning and lubrication. You will need to remove the transmitter case and the VFO escutcheon but you do not need to go inside the VFO itself.  The escutcheon is removed by taking off the VFO knob and two tuning controls on either side and then the mounting hardware becomes visible.  Once this is off you can remove the ball reduction drive and disassemble it; it is pretty simple but do it over a large container in case any of the ball bearings try to drop out and run away and either make a simple sketch or take a couple of digital photos as you take it apart.  Once apart, I soak everything in a little container of WD-40 to get all of the old grease and dirt out.  Then repack and reassemble with a good synthetic lube; I use the same red synthetic lube that I use in a grease gun for my truck and tractor.  The only "trick" is setting the proper tension on the ball drive nut-you want it tight enough to get rid of the slippage but not so tight as to make the tuning stiff.  Be careful not to overcompensate since you have been dealing with slippage as properly adjusted the tuning is very smooth and too tight an adjustment will lead to wear of the reduction drive. 

If it is already worn through dirt/lack of lube you may be out of luck.  Typically the shaft would wear more than the ball bearing; this is fairly common in the RME receivers which use a similar ball drive.  However, most transmitters get far less VFO tuning usage and I have never run across a Johnson unit with a severely worn drive.

If you have never replaced the undersized dropping resistor in the VFO you can do it by removing the left side (your left as looking from the front) of the VFO case.  You will need a good pair of needle nose pliers to do it this way but it avoids the problem of complete VFO case removal.

Good luck with this!

Rodger WQ9E

[N4JOY]

Rodger,

Thank you for your help and advice!  I removed the VFO escutcheon and clearly see the reduction drive but cannot understand how this can be opened/removed without removing the front panel.  I removed the washer/bolt on the face of the panel.  There is a brass bolt and lock washer behind the front panel.  This large brass bolt behind the face does not loosen.  My only thought is to remove the front panel (ugh) and loosen the shaft coupling screws in the VFO -- thereby pulling the unit out.  I guess I am unsure how to access the ball reduction drive.  Does it pull out?  Am I missing something?

Thank you again,

Chris

[WQ9E]

Hi Chris,

I will try to take a closer look at one of my Rangers later tonight to refresh my memory but you do NOT need to remove the front panel or the VFO itself to remove the reduction drive.  I remember that after you take the escutcheon off that removal was very straightforward.  You do need to loosen the set screws on the flexible coupler and I cannot remember if the reduction drive will then slide through the cutout in the front panel or if you need to angle it sideways.  I vaguely recall that you may need to slide it forward a bit to remove it from the insulating coupler and then it can be angled out of the side but it has been a couple of years since I did the last one and I have been inside a lot of different radios since then so I do not remember exactly how it comes out.  You may need to slide the reduction drive forward (after loosening the coupler set screws) and then remove the coupler entirely to get enough room to remove the reduction drive.  Of course none of my Ranger or Valiant manuals are the "assembly" version so the pictures in them are useless for this task.

I have to take care of some university committee stuff for the next few hours and after that I will head down to the basement and slide the case off of my Ranger 2.

73, Rodger WQ9E

[K3ZS]

I downloaded a Ranger 2 assembly manual from the BAMA archives.

[WQ9E]

Chris,

Sorry not to get back to you sooner but it has been a busy several days at work.  I pulled the case from my Ranger 1 to refresh my memory and if your Ranger still has the original coupler supplied by Johnson (it is fairly thin) then you  can removed it entirely by sliding it as far as it will go in one direction while removing it from the other shaft and this will give you room to angle the reduction drive free so it can come out between the front panel and the VFO proper.  If it does not have the original coupler (many of them get broken, especially in Valiants, by turning the transmitter upside down which flexes the front panel) then you may need to loosen some of the hardware so that the front panel can move a little to give you more room.  However I don't think this will be necessary.  Although I don't advise it, you could probably tighten the housing a little on the ball reduction drive without removing it from the transmitter.  This would probably take care of the slippage but if the lubrication has dried up (it probably has) then this is only a very short term solution and it will increase the wear on the reduction drive. 

I thought I took some digital photos of the reduction drive removal and cleaning when I restored my Johnson Pacemaker but if I did I have successfully hidden them from myself on one of the hard drives.  If you get stuck, let me know and I will try to help out further.  Fortunately (or unfortunately) none of my Johnson gear is acting up at the moment so I don't care to fully disassemble any of it-of course I have plenty of actually broken radios awaiting my attention.

P.S.  As I remember the reduction drive has 3 or 4  ball bearings in the sides and one in the rear so make sure that none of those get away.  When you think that you have the tension correct (before putting it back in the transmitter) try turning the input shaft while holding the body and restraining the output shaft; it should take a fair amount of force to make the output shaft slip and if it slips too easily then you need to tighten the housing sections slightly to increase the torque before slippage. 

73, Rodger WQ9E

[WQ9E]

Robert,

Thanks for the note on the manual, I downloaded it so I do have a copy now.  I generally use the edebris reflector but unless the reflector was having an issue the Ranger 2 assembly manual appears to be a damaged PDF.  I did download it from the main Bama site where it works fine but the download took about 9 minutes instead of the few seconds typical when downloading a file that size from the edebris relfector.

73, Rodger WQ9E

I downloaded a Ranger 2 assembly manual from the BAMA archives.

[N4JOY]

Rodger,

I can't thank you enough for your time and assistance.  Your guidance has certainly helped!  After I repair the VFO reduction drive I will still have a few more tasks to perform --removal of a poorly installed PTT mod, VFO resistor, and a few more caps/resistors need replacing.  Thankfully she's in original condition and hasn't suffered the fate of many "modified" Rangers.

On a side note, I am also in academics.  I completed my PhD last year and quickly learned the reality of higher education in Florida.  The hiring freezes and budget shortfalls at our state universities have been brutal!

Thank you again!

Chris 

[WQ9E]

Chris,

I am happy to help and it sounds like your Ranger will soon be in fine shape.

In general, I love being in academe.  I got my Ph.D. (marketing) about 20 years ago so I have been in it for quite awhile although time has passed quickly and I will retire in about 7 or 8 years.  I have a feeling state budget problems are going to be pretty bad for the next few years so it is time to dig a foxhole and climb in for a few months.  I do find myself getting more involved in consulting late in my career and it is far more mentally (and financially) rewarding than the service emphasis that many professors have late in their career; I am especially cynical about service lately as I am chairing a university wide committee that is faced with the basic problem that federal law, ethical guidelines, and practical common sense are at odds with one another.  It is fortunate in many fields that research and consulting go well together and I really enjoy the combination. 

Good luck with your Ranger and your career!

73, Rodger WQ9E