Re: [amsat-bb] Yaesu G-5500 Potentiometer replacement
For what it's worth, I have a rotor that has been going for 14 years, the set screw issue was cured early on with a drop of blue Lock tight, this counts for both the pot drive gear and the motor drive which also has a small set screw that likes to back out and then the rotor runs forever or until the windings fry. I did lose a motor winding once due to a jam so after that I shoved a thermal switch down between the windings to cut power in a over heat situation, 4 lock to lock rotations and it will cutout, the motors that Yaesu used have a very short duty cycle. The Pot... never have had one go really bad where I had to replace it but that #$%^ wire in the middle for the wiper can be vexing, the turning and flexing breaks it and then you get wild extremes or bad readings in one spot, replacing it with the most flexible wire you can winding it like a loose coil and putting a small drop of epoxy at each end to stop wire movement helps it last the longest (several years for me), never had a problem realigning the stops if you make good marks of where it was when you started or if possible you run it to zero before you begin. I have also found that quicksilver marine grease 2-4-c with ptfe works really well and is readily available for the gears and bearings.
YMMV 73 Kevin WA6FWF
On 3/12/2015 11:14 AM, Todd wrote:
I recently bought a _very slightly_ (like new) used Yaesu G-5500 rotator and have had some issues with the indication system. During rotation of the elevation rotor sometimes both indication meters would sometimes fluctuate violently to full scale. Finally the elevation indicator just stopped at 90 degrees and stayed there or went to zero when hitting the zero stop microswitch. Anyway, if figured the position potentiometer was the problem and opened up the unit and _found the gear on the pot shaft was slipping due to the set screw not holding_. Although, it would grab at some point during the rotation cycle again and hence be out of sync now with the motor stop! This grabbing again in the rotation cycle destroyed the pot. Got two (one spare) replacement pots from Yaesu and installed and calibrated very carefully I might add. Adjusted pot to display "0" degrees, installed gear on pot shaft and rechecked indication to be be sure I still read "0". Assembled motor gearing with boom tube so stop switch @ zero just actuated. Installed other case half and checked ok and dead on after standard manual cal. Anyway, just checked the azimuth operation and see that the indication is off at 90 degrees by 10 degrees or so. Watching needle from zero the needle delays in movement by a couple of seconds after motor starts turning. I suspect another set screw slipping again. I will investigate further. I'm getting closer to interfacing the LVB Tracker now. Anyhow, after looking everywhere on this BB and internet for any procedure to change these pots in either rotator I did find this posting from a Yaesu Rep that gives a guide to a individual if he decides to take on the task of changing out the azimuth pot. The Rep advises him to sent the unit to him in California.
Here's a quick question for those that have had the azimuth rotor apart.....
Last year when I packed things up from Field Day, I left the antennas and cross-boom in my "Mini Portable Roof Mount" system. During the drive home, my son noticed the antennas were windmilling in azimuth.
When we got home and unloaded the set up, you could turn the azimuth rotor by hand. It still hits the stops, and I haven't tried to run it, but I'm wondering what shook loose during the ride home.
Yeah, me bad for not pulling the cross-boom out!
I haven't taken the azimuth rotor apart yet (I have 4 complete G-5400 and G-5500 sets), so do you think I really busted something, or did a setscrew just come loose?
73, Jim KQ6EA
PS....I'll be using my "regular" setup for Field Day this year as NI6BB onboard the Battleship Iowa.
On 03/14/2015 06:59 PM, Kevin Schuchmann wrote:
For what it's worth, I have a rotor that has been going for 14 years, the set screw issue was cured early on with a drop of blue Lock tight, this counts for both the pot drive gear and the motor drive which also has a small set screw that likes to back out and then the rotor runs forever or until the windings fry. I did lose a motor winding once due to a jam so after that I shoved a thermal switch down between the windings to cut power in a over heat situation, 4 lock to lock rotations and it will cutout, the motors that Yaesu used have a very short duty cycle. The Pot... never have had one go really bad where I had to replace it but that #$%^ wire in the middle for the wiper can be vexing, the turning and flexing breaks it and then you get wild extremes or bad readings in one spot, replacing it with the most flexible wire you can winding it like a loose coil and putting a small drop of epoxy at each end to stop wire movement helps it last the longest (several years for me), never had a problem realigning the stops if you make good marks of where it was when you started or if possible you run it to zero before you begin. I have also found that quicksilver marine grease 2-4-c with ptfe works really well and is readily available for the gears and bearings.
YMMV 73 Kevin WA6FWF
On 3/12/2015 11:14 AM, Todd wrote:
I recently bought a _very slightly_ (like new) used Yaesu G-5500 rotator and have had some issues with the indication system. During rotation of the elevation rotor sometimes both indication meters would sometimes fluctuate violently to full scale. Finally the elevation indicator just stopped at 90 degrees and stayed there or went to zero when hitting the zero stop microswitch. Anyway, if figured the position potentiometer was the problem and opened up the unit and _found the gear on the pot shaft was slipping due to the set screw not holding_. Although, it would grab at some point during the rotation cycle again and hence be out of sync now with the motor stop! This grabbing again in the rotation cycle destroyed the pot. Got two (one spare) replacement pots from Yaesu and installed and calibrated very carefully I might add. Adjusted pot to display "0" degrees, installed gear on pot shaft and rechecked indication to be be sure I still read "0". Assembled motor gearing with boom tube so stop switch @ zero just actuated. Installed other case half and checked ok and dead on after standard manual cal. Anyway, just checked the azimuth operation and see that the indication is off at 90 degrees by 10 degrees or so. Watching needle from zero the needle delays in movement by a couple of seconds after motor starts turning. I suspect another set screw slipping again. I will investigate further. I'm getting closer to interfacing the LVB Tracker now. Anyhow, after looking everywhere on this BB and internet for any procedure to change these pots in either rotator I did find this posting from a Yaesu Rep that gives a guide to a individual if he decides to take on the task of changing out the azimuth pot. The Rep advises him to sent the unit to him in California.
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
A picture would be worth a thousand words, but lets give it a try, the motor is attached to what looks like a metal "bow tie" and is surrounded by a coil spring with a bent tab at each end, when the motor runs the bow tie grabs a tab and "pulls" the spring with it and the pulling winds the spring in slightly and reduces it's size thus dropping drag, when not running and you try to manually turn it the bow tie is now "pushing" against the spring tab which makes the spring try to get bigger and drag goes up stopping you from moving, if your freewheeling...
A) setscrew loose on bow tie and is slipping on motor shaft b) bow tie is too high or low and allowing spring tab to miss c) rotor got jarred badly and spring got knocked out of position d) previous maintenance put the wrong grease on the spring and it is slipping (how would I know that? lol) should be white lithium and just a little
73 Kevin WA6FWF
On 3/14/2015 8:47 PM, Jim Jerzycke wrote:
Here's a quick question for those that have had the azimuth rotor apart.....
Last year when I packed things up from Field Day, I left the antennas and cross-boom in my "Mini Portable Roof Mount" system. During the drive home, my son noticed the antennas were windmilling in azimuth.
When we got home and unloaded the set up, you could turn the azimuth rotor by hand. It still hits the stops, and I haven't tried to run it, but I'm wondering what shook loose during the ride home.
Yeah, me bad for not pulling the cross-boom out!
I haven't taken the azimuth rotor apart yet (I have 4 complete G-5400 and G-5500 sets), so do you think I really busted something, or did a setscrew just come loose?
73, Jim KQ6EA
PS....I'll be using my "regular" setup for Field Day this year as NI6BB onboard the Battleship Iowa.
Jim, Thinking some more about this I guess you could have also broken the nylon coupler to the gears, will be interested to see what you find..
73 Kevin
On 3/14/2015 9:37 PM, Kevin Schuchmann wrote:
A picture would be worth a thousand words, but lets give it a try, the motor is attached to what looks like a metal "bow tie" and is surrounded by a coil spring with a bent tab at each end, when the motor runs the bow tie grabs a tab and "pulls" the spring with it and the pulling winds the spring in slightly and reduces it's size thus dropping drag, when not running and you try to manually turn it the bow tie is now "pushing" against the spring tab which makes the spring try to get bigger and drag goes up stopping you from moving, if your freewheeling...
A) setscrew loose on bow tie and is slipping on motor shaft b) bow tie is too high or low and allowing spring tab to miss c) rotor got jarred badly and spring got knocked out of position d) previous maintenance put the wrong grease on the spring and it is slipping (how would I know that? lol) should be white lithium and just a little
73 Kevin WA6FWF
On 3/14/2015 8:47 PM, Jim Jerzycke wrote:
Here's a quick question for those that have had the azimuth rotor apart.....
Last year when I packed things up from Field Day, I left the antennas and cross-boom in my "Mini Portable Roof Mount" system. During the drive home, my son noticed the antennas were windmilling in azimuth.
When we got home and unloaded the set up, you could turn the azimuth rotor by hand. It still hits the stops, and I haven't tried to run it, but I'm wondering what shook loose during the ride home.
Yeah, me bad for not pulling the cross-boom out!
I haven't taken the azimuth rotor apart yet (I have 4 complete G-5400 and G-5500 sets), so do you think I really busted something, or did a setscrew just come loose?
73, Jim KQ6EA
PS....I'll be using my "regular" setup for Field Day this year as NI6BB onboard the Battleship Iowa.
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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Jim Jerzycke -
Kevin Schuchmann