If the servo control chip is generally current independent and just looks at voltage, then most any linear pot may work. Below is the only diagram I’ve found so far on the inter workings of a servo.
Yes, that’s it. For an analog servo, the incoming servo pulse is used with the resistor capacitor (RC circuit) to generate a voltage. That voltage is compared to the voltage coming from the pot and the difference causes voltage to be applied to the motor to correct. The pot is not part of the RC circuit so it’s value will not effect operation. I’m sure there are practical limitations for other reasons, like using a 10meg ohm pot, but I see no reason a 10k pot couldn’t be used in place of the 5k pot.
actually for an analog servo controller the pot value WILL have an effect in the feedback gain, or more specifically how fast the servo closes on the destination position. Consider zoomkats schematic, the impedance seen at the feedback pin from the 22K resistor side is changed by the value of the feedback pot (think about thevinin equivalent from the pot side of the 22K resistor). Since the feedback voltage output impedance forms a voltage divider with the back-emf voltage output impedance you should see that changing the feedback pot value will have some impact on the servo performance. 
Hrmph, what he said. lol
hello all
i would like to introduce myself…my name is Patrick.
im into robots and large scale rc cars. robots, fascianting things they are i have a heathkit hero 1 and the tandy armatron who remembers those? lol
neways guys i have a question about this servo amp… the other day i was using the servo and the unit glitched on me several times and ceased to work, upon further investigation it would only turn ccq if i would turn the serv arm back manually, i opened it up and saw what i beleive to be one of the op amps to be burned, neways my question is if i purchase this hs-5745 servo amp, and replace it? will it fix it? i mean the motor seems to be in good working order it turns with power applied and the pot i measured 5k across and varies porotional from mid terminal to both ends.
what else would i need? also did they make different versions of this board? thanks kindly guy…btw on the opposite side of where the motor is mounted the board says hsc5745 and my board looks a little bit different it has no metallic cover like the one featured on this website. would it still work?
Hey Patrick, Nice chatting on the phone. For those who were not listening to our conversation… Yes the amp board will fix your servo. When a servo will only work in one direction it’s one of the H-bridge drivers that is blown. The new board will revive your dead servo. 8)
hey Jim thanks for all ur help…for answering all my many questions and concerns, i placed an order right away after getting off the phone, hopefully they come fast
thank once again Jim