[Elecraft] KFL1-2 vs KFL1-4

[Mike Morrow]

Lonnie wrote:

>I own a 4 band K1 with 40m, 30m, 20m and 15m installed.
>I have just ordered a KFL1-2 for 80m and 40m...

If you have two different filter boards each with 40m on them, you'll be able to store a 40m LCD operating frequency display calibration constant for only one of the filter boards.  These cal constants are stored one for each band in the front panel CPU system, and not on the filter board itself.  This will likely mean there will be a small display inaccuracy on 40m when the filter board is in place that was NOT installed at the time of display calibration.

>... I came across the reference to C78 (10 uf) installed on the
>bottom of the RF board. What is the impact of C78 when I switch
>back to my KFL1-4? Will it have any impact on the four band board?

It won't hurt a bit.  In fact, it might be helpful even on other bands.

The same is true for RF choke RFC8 that's provided only with the 80m kit.  You have to remove a jumper on the RF board and replace it with this RFC.

I'd prefer that RFC8 and C78 were standard parts to be installed when the basic K1 is being built.  Then the K1 would be immediately ready for an 80m board at some future date.

I have an older K1, with a 40/30/20/15m board and a 80/17m board.  Older K1's do not have pads on which to solder C78, and C78 wasn't included in older 80m parts kits.  I installed C78 anyway.  Oddly, no Elecraft bulletin mentions C78 nor states that C78 should be installed on the older K1s also for 80m operation.  I believe it should be.

73,
Mike / KK5F