[TenTec] Encoder shaft stability

[John McAlpine IV]

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!   My 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

> From: k4dpk at comcast.net
> To: tentec at contesting.com
> Date: Tue, 13 Apr 2010 19:23:53 -0400
> Subject: [TenTec] Encoder shaft stability
> 
> I've been toying with an idea and would appreciate input from the group.
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> Haven't had any experience with the Orions yet, but every on other T/T rig with an encoder, I've seen varying amounts of encoder shaft wobble.  If you lift up on the front of the knob, it'll move noticeably and irritatingly (at least to me).
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> The reason for this is T/T relies on the encoder bushing alone to serve as the only bearing surface, and that single-point bearing allows lateral "wiggle".   I think we can give the encoder a two-point support with just a minimum amount of effort. 
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> What I have in mind is a circular piece of say, 1/16" Teflon sheet, about 1 ½" diameter, with a ¼" hole in the center.  Using a nibbler, cut out a bite every ¼" or so from inside of the hole so small "fingers" would be left to contact the shaft.  This would encircle and hold the shaft and still have only a minimum of surface contact area.
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> Then attach the Teflon disc under the knob to the plastic bezel using pins or #2 machine screws.  The latter would be placed outside the track of the tension arrangement.
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> Comments please??  Better idea anyone?
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> Phil C. Sr.
> 
> k4dpk
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