The Geiger Operator was voiced by David Healy.
- The Geiger Operator's puppet was previously used for Lieutenant Dean, the Airport Chief, the 2nd London Police Officer and the the SHEF Guard. It is later used for Clark and Bill Williams.
- In Joe 90 it appears as Captain William Barry in Splashdown, Senator Casper in International Concerto, the Major in Business Holiday, the XV104 Pilot in Arctic Adventure, the Sergeant in Colonel McClaine and a Barman in Lone-Handed 90.
- In The Secret Service, it was used for the London Airport Controller in A Case for the Bishop, the Port Trennick Guard in A Question Of Miracles, Sargent Walsh in Recall To Service and the Air Traffic Assistant in May-Day, May-Day!