Re: BJ question


David Martin <davemrtn@...>
 

Maybe that explains why the tuning pot is wired backwards and requires pcb mods to make it right ??  Just my opinion too.  But I did mod my tuning pot so '10' on the knob is the higher freq and '1' is the lower freq.


David Martin - NA1MH - Mountain Home, Ar. -----------------------------------------

On 2/2/2017 20:38, n5ib@... [4sqrp] wrote:
 

It wasn't the tuning pot that might need trimming, it is the rotary switch.
The tuning pot has to be elevated off the PCB a bit so that there is enough shaft for the knob to grab.

regarding the ATTEN control - that was an executive decision, at least in my prototype. CW rotation = more signal, just like the VOLUME control.  When I first showed the proto I had it wired so that full CCW was minimum attenuation, and the folks who were playing with it remarked that it worked backwards - hi - so I turned it around and left the labeling as is.  Tried to tell them is was designed for the Southern Hemisphere... but that dog wouldn't hunt..

N5IB
.



---In 4sqrp@..., wrote :

Has there been a change in the tuning pot or knob?  I am glad I didn't cut any of the shaft off because my knob snugs right down on the faceplate, and when I put it flush with the faceplate it becomes more stable in staying on frequency and easier to tune.  At first I had it about 1/16 inch above the faceplate to prevent scratching it but it works better down tighter.  Might put a piece of felt behind it like the knobs of yore.

Another question:  why does the attenuator pot work backwards?  I would think, clockwise = more attenuation.  Less attenuation at the 7:00 o'clock position.  Mine is least at the 5:00 o'clock and max at 7:00 o'clock. May have to fix that on mine.

Has anyone found a way to remove the lettering on the tuning pot? Then I could just use small press on numbers somehow relating to the frequency.  7  .03 .05 1.0 etc.  I think I could do it or if someone was good with Word or some printing program print out a ring that we could place on the knob skirt with dots or something we could make a chart for.

Dave K8WPE

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