Rotator Tricks

The rotators in the station are the Ham-IV model manufactured by CDE/Telrex/Hygain. These are very common rotators in the amateur radio service in the US. The "tricks" that we use here were certainly not invented here. These ideas come from various magazine articles, programs, and other experiences.

Use any of these suggestions at your own risk. They work for us. Your mileage may vary.

Remote the capacitor

These rotators use a capacitor. This capacitor is mounted in the control box at the factory. We have moved this capacitor from the control box to the rotator itself. This exposes the capacitor to the elements, but reduces the number of wires required between the rotator and the controller. Having the capacitor at the rotator should cause some improvement in performance, since the series-L from the controller cable is avoided.

Follow the resistor color codes when cabling

When attaching the multi-conductor cable to the screw terminals, follow the resistor color coding as closely as possible. This provides a well-known, deterministic pattern to follow. For those using numbered conductors instead of color-coded conductors, ignore this step. :-)

Install trailer connectors at rotator and controller

We install 6 pole "trailer" connectors at each controller and rotator. This greatly simplifies rotator installation on the tower. Controllers are also more easily moved around the shack when they can be detached from their cable easily. Bench testing is also a snap with mating connectors. A rotator "extension cord" makes our temporary tower installations go very quickly. We chose trailer connectors since they are fairly common, reasonably priced, and somewhat weather-proof.

Our convention is to have the mostly-female connector attached to the controller, the mostly male to the rotator. This practice reduces the chances of shorting the non-mated contacts coming from a live controller. Also, this orients the connector at the rotator (the one exposed to weather) such that its shell is pointed down, so as to NOT catch the rain.

We use lithium grease in the contacts to reduce the amount of weather getting to the contacts.


Ron Luse <ron@rf.org>
Last modified: Tue Sep 9 00:40:58 1997