Posted by
Joe Subich, W4TV-4 on
Aug 09, 2010; 2:57pm
URL: http://elecraft.85.s1.nabble.com/P3-Unexpected-Control-Operation-tp5387731p5389289.html
Bill,
> Alan N1AL may want to respond but I don't believe either is a bug.
> Both are consistent with more sensitivity in the clockwise direction,
> which is consistent in my opinion.
While both controls, in fact, increase a behavioral parameter with
clockwise rotation, the behavior is still inconsistent with other
controls on both the K3 and P3. If the controls were arranged to
adjust an underlying behavioral parameter instead of an absolute
value, the WIDTH control on the K3 should be reversed so that it
increases SELECTIVITY (less width) with increasing clockwise
rotation.
> We need to remember the P3 is not a spectrum analyzer (mainly used
> for measuring spurious signals down from a reference carrier but a
> panadapter (mainly used for identifying weak signals above a noise
> floor).
I don't see how this makes any difference. The P3 controls are labeled
REF LVL and SCALE and not "MIN/MAX SENSITIVITY" and the values they
control have specific numeric values. Their behavior is backward based
on both the numeric values and the behavior of other controls in the
K3/P3 system.
Although one could conceivably argue that REF LVL is ergonomically
correct in that counterclockwise rotation moves the reference level
(baseline) DOWN on screen, I find SCALE to be very confusing since
increasing rotation results in less visible range and a smaller (min
to max) size scale. After all the control is SCALE not amplitude
or trace size.
73,
... Joe, W4TV
On 8/9/2010 10:01 AM, Bill W4ZV wrote:
>
>
> Joe Subich, W4TV-4 wrote:
>>
>>
>> Rotary controls in the K3 and P3 increase their parameter as the
>> encoder is turned clockwise except in two cases.
>>
>> 1) The P3 "REF LVL" is decreased with clockwise rotation. Maximum
>> reference level is -10 dBm with the encoder fully counterclockwise
>> while it is minimum -160 dBm with the encoder fully clockwise.
>>
>> 2) The P3 "SCALE" (range) is decreased with clockwise rotation.
>> Scale is minimum (10 dB) when the encoder is fully clockwise
>> and maximum (80 dB) when the encoder is fully counterclockwise.
>>
>> Both of these controls violate the principle of "expected" behavior
>> and consistent operation.
>>
>
> Alan N1AL may want to respond but I don't believe either is a bug. Both are
> consistent with more sensitivity in the clockwise direction, which is
> consistent in my opinion. In the case of REF LVL, turning clockwise until
> the noise floor becomes visible seems correct (i.e. like turning RF GAIN
> clockwise in a traditional radio). In the case of SCALE, it means less
> visible range above the noise floor which means more resolution of weak
> signals.
>
> After using the P3 I find the current conventions intuitive. While they
> might not be technically consistent (in terms of the values being set) I
> believe both are consistent and intuitive in terms of practical use. We
> need to remember the P3 is not a spectrum analyzer (mainly used for
> measuring spurious signals down from a reference carrier but a panadapter
> (mainly used for identifying weak signals above a noise floor). Either
> *can* be used the other way around, but I believe the controls of both are
> set up differently for good reasons.
>
> 73, Bill
>
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.html