[Elecraft] Re: K2 vs OMNI V keying waveform?

Thu May 1 23:05:02 2003

I just ran a completely unscientific test on my K2 (#489) to get a rough
idea of the key click situation.

With the dial set on 7050 KHz, the PRO2 S-meter read S9+30 dB as a
reference.

Keying the K2 at about 30 wpm with a string of dots and putting out 5 watts
into a dummy load, I tuned up and down 1 KHz and read S5 on the meter with
the clicks good and loud. I could still hear clicks but with S0 readings up
to 5 KHz above and below 7050.

Now comes the coincidental part . . .

On the PRO2, the S-meter is quite accurate above S9 so there is a pretty
good 30 dB right there. From S5 to S9 is pretty close to 6 dB per S-unit for
24 more dB. Add that up and you get 54 dB. Or, the clicks were -54 dB at +/-
one KHz from the main frequency.

Comparing that with the Inrad piece that Jerry referenced, I see that they
measured +/- one KHz on a real spectrum analyzer at -54 dB. Coincidence? Of
course, but probably within 6 dB of being good data.

So, the point seems to be made that at least for my K2 it is rattling things
up pretty good for at least a KHz each side and can be heard out as far as 5
KHz.

So what do we make of all this?

73/72, George
Amateur Radio W5YR -  the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
"In the 57th year and it just keeps getting better!"
<mailto:[email protected]>

----- Original Message -----
From: "Jerry T Dowell" <[email protected]>
To: <[email protected]>
Sent: Thursday, May 01, 2003 7:09 PM
Subject: [Elecraft] Re: K2 vs OMNI V keying waveform?

> Hmm. According to these measurements, the K2 is the worst of the lot! That
> doesn't correlate well with on-the-air listening to klicky MP's etc here.
I
> haven't heard any strong K2 sigs, but klicks are evident on MPs even when
> sigs are modest. With the published K2 keying waveform (very sharp
trailing
> edge), one would expect klicks. Earl's observations are certainly
> indicative. I suggest that additional investigations are in order.
>
> Jerry  AI6L
>
>
> "" Some measurements comparing key clicks among rigs, including the
> FT1000MP, OMNI VI+,  and  K2, appear on the following website.
>
> http://www.qth.com/inrad/about-key-clicks.pdf
>
> Lou W7HV ""
>