[Elecraft] K1 - VFO frequency range

[roney]

Hello Mike and Cameron, I appreciate your tips.
I adjusted the L1 inductor, getting 3.500,3 mhz and 20.098,2 mhz on VFO.
That was perfect to me.

(updating Cameron about the email)

So I moved the rig to another place and used another PSU (first using a
12,4v, and after using a 13.8v PSU)
I noticed that this minimum frequency changed to 3.501,2 mhz.
No problem about that.

Thanks and 73,
de PY1ZB, Roney

On Wed, May 24, 2017 at 11:56 PM, Cameron Francey <
cameronfranceyutils at hotmail.com> wrote:

> Just as an additional note.  I built two K1's last year and even though I
> wound the turns for L1 so they were really tight as I found from experience
> its much easier to spread them out a bit than to compress them again.  In
> both K1's I actually had to remove one turn to get the VFO low enough.  The
> manual does mention this may be needed.
>
>
> Just though I'd bring that up since I had to do that fairly recently.
>
>
>
> Cameron - AF7DK/GM7LQR
>
>
>
>
> ------------------------------
> *From:* Elecraft <elecraft-bounces at mailman.qth.net> on behalf of Mike
> Morrow <kk5f at earthlink.net>
> *Sent:* Wednesday, May 24, 2017 9:04 AM
> *To:* roney; elecraft at mailman.qth.net
> *Subject:* Re: [Elecraft] K1 - VFO frequency range
>
> I assume you have already calibrated the LCD display on each band using
> the OCF menue function.  That makes the LCD indicate the actual transmitter
> output frequency,  This display calibration for each band must be performed
> before adjustment of where the low end of each band starts.
>
> Because the K1 has no way of adjusting the oscillation frequency of the
> individual heterodyne crystals on the filter board, the only band edge
> adjustment possible is accomplished by altering the VFO frequency.  That
> affects both bands equally.
>
> Your data show the K1 tuning band is too low by about 5.2 kHz.  The VFO
> SUBTRACTS from the heterodyne crystal frequency, so to RAISE the K1
> frequency of operation you must LOWER the VFO frequency by squeezing CLOSER
> together some of the turns on the RF board L1 VFO toroid.  It won't require
> much.  Try that until the low end of 80m indicates about 3499.0 kHz on the
> LCD.  That 80m L1 adjustment will also bring the low end of 15m to about
> 20996.1 kHz.  That will be the closest you'll get on 15m.  If you adjusted
> L1 until 15m starts at 20999.0, then 80m will start at 3501.9 kHz.  You'll
> have lost some low end 80m coverage.
>
>