[Elecraft] XG1 musings

[Allen Ward]

Donald Nesbitt wrote < By
calculation I got -142 dBm with preamp on and by using both Spectrogram and
Spectrum Lab for the "visual" method, I get -144 dBm.  Close enough for
government work!  The preamp-off test shows about the same amount of
agreement.>
As I reported a few days ago I measured -134 dBm using the voltmeter method
for my K2.  I decided to check using Spectrogram and got
 -144 dBm.  My research on ARRL tranceiver comparisons both  pre and post
1990 show the best measured MDL to be -144 dBm for an IC 745 and  a number
of -135 to -143 readings for other rigs.  The K2 received a -137/-138 dBm
rating.
How much variation can one expect in assembled kits due to alignment etc.?
3 to 4 dB seems a reasonable number.  How close can you interpolate the dB
scale of the Spectograph?  How well does your sound card perform, any
distortion, non-linearity?  I suspect that the AC voltmeter method is more
accurate especially since the Spectograph (even thought it is easy to use)
seems to indicate a higher number than should be expected.  Maybe someone
with better equipment can put some light on the topic.
Thanks Allen KA5N