[Elecraft] K1 band change Issue

[William LeComte]

Mike,

Thank you very much for taking the time to give these details.  This is
extremely helpful.

Bill
KB1DX


On Mon, Jun 17, 2013 at 10:10 PM, Mike Morrow <kk5f at earthlink.net> wrote:

> Bill wrote:
>
> > ...What I observed is when the Band switch is used
> > to cycle through the bands 30 meters does not show up in the display, but
> > 20 meters appears to show up twice.
>
> The K1 does *not* know automatically which bands are available on any
> filter board that is plugged in.  That is why the procedure at the bottom
> of page 16 of the KFL1-4 manual (rev. A) must be used to manually tell
> the K1 MPU what bands the plugged-in filter board possesses.
>
> Completing that assignment process causes the K1 to format the frequency
> display (LCD) as appropriate for the assigned bands.  In addition, each
> amateur band 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, and 10m has a
> band-specific display frequency calibration constant stored in the
> K1 MPU.  This constant is set automatically when you perform the OPF
> (operating frequency) calibration for that band (page 18 of the KFL1-4
> manual).  So...the other thing that happens (in addition to LCD formatting)
> when you assign a specific HF ham band to band b1 (b2, b3, b4) is that
> the previously-stored OPF calibration constant for that ham band is
> automatically assigned to band b1 (b2, b3, b4).
>
> Aside from that, a band assignment does **not** actually affect the
> operation of the rest of the K1.  You could manually assign *all* bands
> as 20 meters, yet when you cycle through band b1 (b2, b3, b4), the K1
> will still actually still function on 40m (30m, 20m, 15m), even though
> the displayed frequency *appears* to be 20m for each band.
>
> > One of the appearances of 20 meters functions, but the other does not,
>
> That seems to describe your seeing 7.xxx, 14.xxx, 14.xxx, 21.xxx in the
> LCD as you cycle through the bands.  (Normally you should see the
> repetitive
> display of 7.xxx, 10.xxx, 14.xxx, 21.xxx as you cycle through.)  If that
> is correct, then which of the two 14.xxx bands does not function?  If the
> one that doesn't work is the first 14.xxx after 7.xxx, then apparently
> you have a problem with band b2 on you KFL1-4...the band position that
> should be 30m.  Just re-assigning b2 to 30m (either 10.000 for an 18.000
> MHz filter board crystal or 10.100 for an 18.100 MHz filter board crystal)
> will *not* fix the non-functioning band.  You should go ahead and assign
> b2 properly, but then your real troubleshooting begins.
>
> OTOH, if the band with the *second* "14.xxx" display is the one that is not
> working, you have troubleshooting to do on your 20m filter circuitry.  The
> 30m circuitry is likely OK, although K1 b2 needs to be re-assigned to 30m.
>
> As far as troubleshooting a bad 30m band, you could attempt to re-align the
> 30m (b2) capacitors on the KFL1-4 per its manual.  However, that will also
> then require re-aligning the 40m band as well.  (Part of the 40m resonant
> circuits make use of the tuning circuits of 30m.)
>
> If you are not successful in returning the 30m band to operation by
> re-alignment, then you'll need to look for another failure.  The most
> common
> reason for a K1 band to be totally dead is a bad heterodyne crystal on the
> filter board.  Do you have a receiver that could be used to hear the 30m
> crystal near 18.000 or 18.100 MHz (+/- about 10 kHz), when b2 is selected?
>
> > ...which is likely 30 meters not being recognized and showing up as 20
> > meters.
>
> Definitely not.  The only way your K1 knows what ham band is assigned to b2
> is from the band assignment that must be performed manually.   The K1 does
> not sense or otherwise know if any or all bands on a filter board are
> working
> or dead.  The only information that the filter board gives to the front
> panel
> MPU (the central 'brain' of the K1) is whether it is a two-band or
> four-band
> filter board.  That way the K1 knows whether to let you assign a specific
> ham
> band to just b1/b2, or to b1/b2/b3/b4.
>
> That part is definitely working.
>
> Mike / KK5F
>