[Elecraft] FTDX5000 Design Flaw

[Jim Brown]

On Sat,11/20/2010 12:48 PM, John, KI6WX wrote:
> The ARRL is aware of this issue.  This problem was discussed in my 1988
> articles on phase noise in QST (March & April issues).  The article notes
> that a high phase noise transmitter degrades the performance of a low phase
> noise receiver to that of the transmitter.  This article started the ARRL
> making composite transmit noise measurements.

I've recently added fuel to the fire with an online document plotting 
ARRL TX data for multiple radios on the same graphs, making comparison's 
easier. I did that by taking data point by point off of ARRL's published 
plots, then putting them in my own spreadsheet. I did that for both 
keying spectra and phase noise.

Seeing that document, Bob Allison sent me the raw data for the CW keying 
spectra for those radios, and I've been processing and plotting that 
data. He was not able to provide the phase noise data in electronic 
form, so we're stuck with what I am able to eyeball from the published 
plots.

You can see an "in-progress" version at k9yc.com/TXNoise.pdf

73, Jim K9YC