[Elecraft] K2/100 - Power investigation

[David Wilburn]

Ok, I got all kinds of numbers off of the DL1.  The Bird seems a touch 
low, showing 80 - 100w across all bands.  Every time I measure it a 
different way, I get different numbers.  Very frustrating.  The W1 
quit after about 5 min.  The MFJ meter gives one reading, the Bird 
another, using the DL1 and doing a calculation, goes crazy on 10&12m 
but more stable, and once again different on others.  Friend is going 
to loan me his Bird, think it is a 4309, and we will see what it 
shows.  I have put the Bird between the K2 & the KAT100, and 
transmitted and then ID'ed, and got the 80 - 100w.  Am I chasing my 
tail?


Dave Wilburn
K4DGW
K2/100 - S/N 5982


Don Wilhelm wrote:
> David,
> 
> The diode in the DL1 recitfies the RF and you read the DMM in DC volts.
> The DL1 uses a peak reading detector across half the load, so the DMM 
> will read 1/2 of the zero to peak RF voltage.  At low power levels (less 
> than 1 or 2 watts), you should add the diode drop to the indicated 
> voltage before calculation of the power, but at higher power levels the 
> diode drop is not significant.
> 
> BTW: The power formula in the DL1 manual has a small error that shows up 
> when calculatiing low powers.  The proper formula can be simplified to P 
> = 2x (Vdmm + 0.15)^2/50  - that is: add 0.15 to the DMM reading, square 
> it and divide by 25 - the 0.15 term is an assumption for the diode drop, 
> those who would like more precision can measure their particular diode 
> forward voltage drop.
> 
> 73,
> Don W3FPR
> 
> David Wilburn wrote:
>> With the DL1, when you do the calculation to get the power level, what 
>> do you measure with?  V-AC or V-DC?
>>
>