[TowerTalk] Prosistel 2051 rotator

[Dave Sublette]

The pot is accessible beneath a bottom plate on the gearbox.  Unless you suspect a mechanic problem with the gears, do not open the gear box.  Before disassembly, put the rotator at North, or some known heading.  Measure the resistance between all terminals on the pot.  Write it down and when you put the new pot in place, set the resistance  to the same value.

If you have a 10K pot, you might think about converting the system to 500 ohms.  this should give better resolution. You will have to change the gain of the circuit in the control box.  The information is probably found with a Google search.  Buy your replacement pot from an electronic components dealer, not the distributor of the rotator.  It should be cheaper that way.  It would be a 500 ohm, three turn pot versus the 10K, ten turn unit that comes standard.

If you wish, put the rotator on the bench and apply a DC to the motor leads and watch the action of the pot on an ohm meter to verify erratic operation.  You might just have  a cabling problem and not a problem with the pot.  Do NOT turn the motor this way more than 180 degrees in one direction  and return it to the resting position before disconnecting.  There is some chance of turning the motor and pot beyond the end and breaking it.  Not as likely with the ten turn pot as would be with the 3 turn pot.

Good luck.

73,

Dave, K4TO

> On Dec 19, 2017, at 5:58 AM, Max Cotton <M0GHQ at outlook.com> wrote:
> 
> I am looking to strip down my PST 2051 in a few weeks time as it has become erratic on its feedback, are there any diagrams or a parts list as I am sure the seals and obviously the Pot will need replacing, looked on the web but scant information.
> 
> 73 Max M0GHQ
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