[Elecraft] Rescaling the W2?

[Jack Brindle]

Note that this affects all Power measurements in the W2 (but not SWR). This means that the serial data will be scaled by the same amount.
It will have affects on the auto-switching in the unit, as well as the alarm function. This means that if you set the alarm for 1000 watts and set the scaling so that 1000 watts is read as 500 watts, you won’t get an alarm. Conversely, if you scale so that 500 watts is indicated as 1000, you will see an alarm.

I would not recommend modifying the connections into the pickup unit - you would have to modify all of the sensor connections, and it would have adverse affects on our ability to detect characteristics of the unit.

Changing the scaling might be interesting for your use, though. If you try it, let us know how it works out for you.

73,

- Jack Brindle, W6FB


> On Nov 20, 2015, at 9:07 AM, Alan <n1al at sonic.net> wrote:
> 
> I just tested it.  The maximum you can set the W2 calibration value to is 650.  (Using the ">" and "+" RS-232 commands)  That causes the wattmeter to read about 60% high on my W2.  So with the W2 set to read 2000W full scale, the actual full scale would be about 1250W.
> 
> Or you could go in the other direction.  The minimum calibration value is 350, which causes the power to read about 47% (on my unit).  With the W2 set to read 200W full scale it would actually be about 425W full scale.
> 
> Alan N1AL
> 
> 
> On 11/20/2015 07:15 AM, Cliff Frescura wrote:
>> I find the scaling awkward as well.  My W2 is placed on the input side of my
>> KPA500 and it seems that dividing the scale by two might do the trick.  I've
>> not looked at the schematic, but wonder if it could be tricked by a resistor
>> divider in the sensor line.
>> 
>> 73,
>> 
>> Cliff K3LL
>> 
>> -----Original Message-----
>> From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Don
>> Wilhelm
>> Sent: Friday, November 20, 2015 5:55 AM
>> To: Scott Townley; elecraft at mailman.qth.net
>> Subject: Re: [Elecraft] Rescaling the W2?
>> 
>> Scott,
>> 
>> I believe that would require a new sensor and firmware to support it.
>> Popular scales on wattmeters are 200 watts and 2000 watts full scale, so you
>> are not going to get much better with another brand product.
>> The W2 used with its utility program can give you more resolution, but then
>> using the Utility when mobile would not be advisable.
>> 
>> 73,
>> Don W3FPR
>> 
>> On 11/20/2015 8:32 AM, Scott Townley wrote:
>>> I know the W2 can be "dialed in" to match one's personal standard,
>>> but...can it be completely rescaled?
>>> I use the K3/KPA500/W2 mobile, and the KPA500 is mounted in my pickup
>>> bed so the W2 is the only system meter available at the operating
>>> position.  However, the 2's scaling doesn't give me much display
>>> dynamic range...the KPA500 will only light 5 of the 17 LEDs at full
>>> power.
>>> It would be far more useful for me to have the meter scaled to 600W
>>> say...then the 15th LED would be 450W.  Even scaling it to 1000W would
>>> give me more than half the display range.
>>> 
>>> 
>> 
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>> 
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