The system as quoted below is typical of most rotators.
73 de G3YXX
In message <[log in to unmask]>, David R. Basden
<[log in to unmask]> writes
>Two of the lines in the cable to the rotor connect to a pot in the rotor
>that changes resistance as the rotor turns. This can be used to control
>the pitch of an audio oscilator. The circuit for the oscillator was in QST
>over 20 years ago. I don't believe I have the information any longer, but
>it should be available if you search for it. Essentially the way it works
>is to rotate a rotary switch till the pointer is in the desired
>direction. The rotary switch selects among various fixed resistors. The
>pitch of an audio oscilator changes as you rotate the switch. A push
>button switches between the pot in the rotor and the resistors on the
>rotary switch. You just rotate the antenna until the pitches match. I
>wish I could be of more help.
>
>73,
>
>Dave, A F 6 Y
>
>At 11:04 PM 6/9/03 -0400, you wrote:
>
>>I'd like to get a beam back up for HF. My Ham IV has been packed away for 7
>>years since coming from the old QTH. At that time I could still look at the
>>meter and see where it was pointed. Can this thing be made accesible?
>>Perhaps via computer control?
>>
>>73 Steve KW3A
>>[log in to unmask]
--
David W Wood