Hello guysI was just hanging around at simspares.com when I came into this:Is it possible to wire something like that? I mean, without using digital displays, but those "rotary" numbers...Thanks a lot.!Paulo

Paulo,In principle, yes it is possible to wire a radio control head like this to FS. The details will vary depending on the unit, but behind the mechanics of the number display and gears, there are several decks of rotary switches. The switch contacts may be wired directly to a large muli-pin connector or may have some diode encoding before going to the connector.The individual switch contacts can be wired to an interface, though there may a large number of them. If the switches are arranged in a decade fashion (i.e. a switch deck for units, a switch deck for tens, etc..) you can use diodes to encode each deck to a four bit binary-code-decimal field.Besides, You WANT that control head, You NEED that control head, I can hear it calling YOUR name... Paulo, Paulo, Paulo...Mikewww.mikesflightdeck.com

Well, thanks........ I kinda understood what you said, but I didn't understand the diode encoding issue... Can you clarify that to me, please..? :)Thank youPaulo

Paulo,Using the diodes reduces the number of needed binary inputs to your FS computer. For example if you had three 10-position rotary switches there would be 30 inputs. If you use encoding, each 10-position switch needs only 4 inputs for a total of 12 inputs. This works because only one of the 10 positions is active at a time.You can use a number of approaches instead of diodes. Logic gates will work, but diodes are cheaper.Mikewww.mikesflightdeck.com

All right, I understood... But how would you wire that to FSBUS?Thank youPaulo

Paulo,FSKey is the binary input option for FSBus. A likely approach is to wire the rotary switches to have BCD outputs.The actual switching configuration of any particular surplus radio control head is unknown. Older radios used banks of crystals that were selected by the control head switches. Several crystals would be active at a time. Their individual frequencies would be combined and filtered for use by the radio. The actual arrangement of switches used in the control head depends on the radio architecture.If the switching arrangement makes use of 10-pole rotary switches, they can be used with diodes to produce a BCD output that should work directly with FSKey.If they switches are otherwise, it may be possible to still use something similar to BCD encoding feeding FSKey. At worse the individual switch contacts could be connected to the FSKey inputs, though that would take a lot of inputs.Mikewww.mikesflightdeck.com

Well... If I use diodes, should I wire all 10-poles of the switch to the diode and then to FSKEY??C'yaPaulo

Paulo,The attached pix shows the wiring for a generic generic BCD switch. It should work with FSKey. I don't think you would need the pull up resistors, but I am uncertain.Mikewww.mikesflightdeck.com