[Elecraft] K2 phase noise

[Fraser Robertson]

Thank you for the responses and I'm pleased to get some discussion going on 
this subject on the reflector.  Phase noise has been brought up before, but 
not discussed in detail.  As I said I've had personal emails about this so I 
know I'm not on my own here.

I should point out that my comments were not intended to 'slag off' the K2, 
and I am not 'obsessed by numbers'.  I don't expect the K2 to have lab grade 
performance, nor to outperform high price rigs.  My sole reason for looking 
into this (believe me I've got better things to do) is due to complaints 
about my signal on air.  These have been from respected and technically 
competent amateurs.  I can go into detail if required.

Several months ago I had some exchanges with Gary and Eric, and sent them 
some analyser plots.  More recently I've done comparisons at 300Hz from 
carrier using a HP8640B as a reference, and I soon should be in a position 
to produce more detailed plots of the close in phase noise.

Although the comparisons I've made clearly show the K2 is inferior to the 
MP, 870 and a home brew rig in this respect as stated, the phase noise 
performance to me seems adequate, however, that doesn't explain the comments 
I've received on air.  I get very similar results with two K2's, one built 
by me and another by GU3MBS, who is a very experienced K2 builder.  Both 
have all the latest mods.  At other times I've received good reports, 
possibly from less critical operators?  I want to get to the bottom of this 
so that I can confidently use my K2 for QRO contesting.  The rig has many 
fine attributes and I take my hat off to Wayne and Eric for their excellent 
design and production engineering.

By the way I've moved the K2 as far as practical from hum sources (>2') and 
even tried enclosing it in a mu-metal shield, so I'm pretty confident that 
magnetic modulation isn't the culprit.

73 Fraser G4BJM

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