[Elecraft] KH1 BFO Adjustment Question

[W3FPR]

Matthew,

I do not know the KH1 for certain, but I would suggest anyone attempting 
to adjust the BFO frequencies use an audio spectrogram analyzer like 
Spectrogram or other audio spectrum analyzer to visually show you where 
the peak of the audio response may be. Adjust the KH1 (or K1, K2, K3) CW 
response to peak at the CW note that you prefer.  The visual screen will 
show where that is.  Set it at your preferred sidetone note.
If you have 'perfect pitch'(like Wayne), you may be able to do it by 
ear, but for those like me, I need the visual assist.

I enjoy music, but have trouble matching tones - I may be as much as 50 
Hz off with my ears alone.  I need the visual spectrum analyzer.

That has nothing to do with the FL1/FL2 question, bur may provide some 
insight into the process.  Whether FL1 or FL2 is to be aligned first 
will be revealed by the audio spectrum analyzer that you use.  Try both 
sequences and see what happens.

Wayne will not document the use of an audio spectrum analyzer for 
setting the BFOs and the passband positioning - I have been through that 
with him before some time ago.

73,
Don W3FPR

On 7/7/2025 5:57 PM, Matthew Kaufman via Elecraft wrote:
> Good afternoon -
>
> I was discussing the BFO adjustment instructions on page 26 of the KH1 manual with a friend of mine, and he pointed out something interesting that has both of us confused.  In the provided instructions, they first tell you to use FL2 when making the adjustments.  However further down, the instructions mention using the BFO frequency that you set for FL1… should those subsequent instructions say FL2?  Should you initially start setting this with FL1 set?  The instructions aren’t exactly written clearly from a step-by-step perspective, and the confusion on which filter you’re adjusting don’t help.
>
> The lead-in to the step-by-step indicates that you should re-align the BFO for both FL1 and FL2, but the instructions seem to mix the two together in the step-by-step and don’t seem to have you adjusting settings for both sets of filter settings (on USB and LSB).
>
> Wayne, is this just something where updated/corrected instructions are needed?  Can you (or someone) please clear this up?  Thanks.
>
>