[Elecraft] RE: K2 Frequency Alignment

[Wallace, Andy]

> -----Original Message-----
> From: Rich Lentz [mailto:ke0zx@cox.net]
>
> BUT, even after alignment this way, running call pll, etc. =20
> WWV at 10 mhz is off by 30 hz and WWV at 20 mhz is off=20
> by 80 mhz, after a 30  minute warm-up and stays there. =20

It's just a guess, or perhaps I am remembering earlier
discussion from the reflector, but isn't this related to
the fact that 10.0 and 20.0 MHz are outside the ham bands?
In other words, doesn't CAL PLL set the most accurate readings
in the ham bands, and you're not necessarily going to get
that kind of accuracy outside?

When you set the 4 MHz osc to beat against 20 MHz WWV reception,
that DOES set the oscillator spot on. But the CAL PLL may
not make things so accurate when it actually sets up the
frequency steps.=20

Blame Art Collins for us being so picky. It was the 75A(1) ham
receiver which had the 100-kHz-per-turn linear PTO and first
got us to expect to know where the heck we were on the bands.

I agree with most people here - the performance (real signal
reception) of the K2 takes precedence over whether the dial
is accurate compared to a lab standard. Personally, I stay=20
>500 Hz from the band edges anyway.=20

Andy

PS one tip in doing the 20 MHz WWV technique might be
to (temporarily) set one of the SSB filter BFO frequencies
to the center of the passband, so you can hear both sidebands.
Then, the zero beat will become easier to spot - you can rock
the trimmer between two settings and hit the midpoint for=20
zero beat by ear, if you don't have an oscilloscope or soundcard
handy.