This was the last major change to date on this series and its popularity continues. However, as the years progressed, the material in the brake wedge somehow changed, and problems started to develop like broken wedges in Late inC. The other most noticeable change was the switch to black plastic covers on the control unit, probably to save money, and changing the color of the faceplate also to black. This was copied from the T2X, but we'll get to that shortly. The improvement consisted of making the ring gear out of steel, actually cast out of a low-grade stainless steel and then machined for a precision fit to the other gears and the main casting. This model came soon after the Ham-3, about Januarybecause all these new large antennas tended to break the cast, pot-metal type of ring gear used in the "bell-rotors" since the beginning. Also at that time, the control was modernized internally with a printed circuit board to replace the old "point to point" wiring style.Ī disc pre-brake was also added to the motor to stop "coasting". This was an incredible improvement, and is still being used. Ham Radio Basics-Jim Heath W6LG Discusses Antenna Gain, Yagis and Rotators Monoband yagis with "looooong' booms were becoming more common to the point of being normaland that "pointed" steel brake wedge just wouldn't hold.Ĭonsequentially, a new wedge was developed that was squared off on the end, and a new brake housing design was built to match. The wedge brake style which had served so well for almost 20 years was being overloaded more and more often by antennas with boom lengths that exceeded that of the average tri-bander.
This model came out in the spring of to fulfill the needs of contesters and other "big-guns" whose antennas continued to get larger as the 70's and technology progressed. The improved control was larger and more roomy inside, therefore lending itself nicely to the options which appeared later.Įarly versions of the Ham-II control unit had metal covers which were two shades of brown later controls had covers which were black and white. The most logical explanation is simply that a separate control was needed for the brake because as large antennas continued to grow in popularity, the instant stopping feature of the older style was causing more and more breakdowns. Ham-M's continued until December This model showed up in January and a number of rumors exist as to why this new control was developed. No major changes occurred in and when the later Ham-M SERIES 4 and 5 were brought out, but minor improvements continued to be made in reliability. Ham-M series 3 showed up late in after numerous complaints about the wiring and the meter "flutter" and the "backwards" scale. While these earlier units can 1953 dwheat penny value rewired, it is not generally considered economically feasible nor worth the time to convert.
This was the result of beefing up considerably the older style TV rotators with stronger, heavier gears, a "pointed" wedge brake, and an improved indication system for direct readout to a meter with a scale for NESWN and degrees from 0 to This model, Ham-M first debuted in November The first Ham-M's, series 1 and 2, used a wiring format that was different and not compatible with later units. As "Ham Radio" antennas became larger and larger during the 50's, the need for larger rotators became evident, so sometime aboutwork started on a heavier design with a separate brake feature to keep the antennas from "windmilling.īut gado gado recept, the Ham-M. The general line of "bell rotors" was developed by engineers at Cornell Dubilier Electronics about starting with the TR-2 and TR-4 series of rotators designed for directional TV antennas which were just then becoming popular.