[TenTec] Encoder shaft stability
Dr. Gerald N. Johnson
geraldj at weather.net
Wed Apr 14 09:28:09 PDT 2010
On 4/13/2010 11:29 PM, John McAlpine IV wrote:
> I have two Jupiters of 2002 vintage and an OMNI 7. I removed the Adjustable Drag Bezel (and all associated hardware) completely on all three units and went to the heavy weighted Orion II Knob with optional Soft Rubber (traction) Ring--with all Knobs pushed as far back onto the Encoder Shaft as possible (while still safely just clearing the Front Panel). Note that the space taken up by the Drag Bezel Assembly spaces the inside face of the Tuning Knob approximately 1/4 inch or more farther out from the support of the Encoder Bearing than what I am suggesting. This modification greatly reduced any perceived Tuning Knob "wobble" along with any mechanical "side-loading" of the Encoder Bearing because of the significantly reduced shaft "leverage" length. I think it looks much "cleaner" than the "stock" configuration. The Bezel (as a result of it's poor design) is often physically "off-center" and appears to "wobble" even if the Tuning Knob itself is perfectly centered! M
y personal taste is to have the least drag on the Tuning Knob as possible--where I can literally spin it for fast frequency changes if/when desired. Whereas there is an electronic "Frequency Lock" Pushbutton on all three units--there is no need that I can see for any "drag" to prevent accidental frequency changes--even under (high vibration) mobile operating conditions. My view is that the "stock" Units should be originally manufactured by TEN-TEC just as I have suggested. I was MOST impressed with the improvement in the "feel" of the Tuning Knob with the above-described modification.
> If on the other hand--you just like the feel of some "drag" on the Tuning Knob--then you must forget my suggestion!
> John McAlpine / KZ4B
Or slip a layer or two of felt between the back of the cleaned knob and
the panel for friction controlled by how tight you push the knob against
the felt before tightening the screws. And that felt washer, if nearly
as large as the knob, will supply tilt support to the knob. Adequate
felt is available for about a buck a square foot in various colors in
the craft department in some wallyworlds. Or by the square yard in most
any fabric shop. You need about 4 square inches per knob.
73, Jerry, K0CQ
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