Tuning CW Stations in 160 meter contest

Elecrafters....
 
I participated in the 160 Meter CW contest this weekend with my K2/100 and noticed something I had never noticed before.  I think that I might have a misadjustment in the filters and I am not sure where.
 
I would tune a station (S&P) to where I thought I was in the bandpass of the RC station.  At least the note sounded good to me.  Invariably, I would have to tune about a tenth of a KC down to actual make the contact.  I could call on the higher tone and they would not hear me, but calling on the lower tone they would come back all the time.  I have the filter center set at 700 with filters widths at 1.5 - 700 - 400 - 100.
 
Do I have something set to low or to high with the BFO?  This gets confusing to me.
 
Lee - K0WA
 
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[John-478]

At 07:01 AM 06/12/04 -0800, you wrote:
>Elecrafters....

>I participated in the 160 Meter CW contest this weekend with my K2/100 and
noticed something I had never noticed before.  I think that I might have a
misadjustment in the filters and I am not sure where.<

I think you are OK Lee. I noticed a lot of that also, but I had to tune
some high and some low while S&P. I think the problem was with where the
distant end operator had their filters set. Judging from how crowded the
band was, most were running with very narrow filter selection. I was very
pleased with how well the K2's heard on 160M, no pumping or IMD.

John, k7up
k2's 2012/2223

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[Steven Pituch]

Pressing the "Spot" button, if you can zero beat the signal, you will be
less than 1 Hz from the other stations signal, if the other station's RIT is
not on.  Then if you can put your 100 Hz signal on, he should still be heard
on your K2.  A great way to catch a Fox.

If the station he is presently listening to is off his transmit frequency,
and he is obviously using his RIT, try zero beating the station he is
listening to because that is where his receiver is tuned.  Also a great way
to catch a Fox if the Fox is operating split.

Steve, W2MY

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[Don Wilhelm-3]

Lee,

If you are using the default 1.5 kHz CW bandwidth for FL1 and listening with
a more narrow filter, the answer is 'quite likely'.  Remember that the FL1
BFO is always used for transmit.  This results in a filter alignment
situation that is seldom mentioned - that of transmit frequency offset.

This problem happens readily if you center the bandpass during filter/BFO
alignment and are using a filter wider than twice your sidetone pitch.  If
you think about it, you should quickly determine that to actually center a
1.5 kHz bandpass on a 600 Hz point, the bandpass will be from 1350 Hz down
to -150 Hz  -- yes, I said that right, the passband will cross over into the
opposite sideband!  The more likely thing is that you did not set it up that
way, so the BFO for FL1 is shifted about 500 to 1 kHz from the remaining
BFOs.  That is the reasoning behind my recommendations that CW FL1 be set no
wider than 2 times the sidetone pitch.  The 700 Hz width is my preferred
normal CW receiving filter width, and I personally set my FL1 to 1.0 or 1.1
kHz to avoid having to shift the FL1 BFO far away from the other BFOs.

I do wish that the K2 in CW (and RTTY modes) always used the same BFO for
transmit as that used for receive, but such is not the case - FL1 is always
used for transmit in any mode (it is necessary in SSB mode).
If the FL1 BFO is not close to the same frequency as the BFO currently being
used for receive, your resulting transmit offset will be quite different
than your sidetone pitch.  (Note: IMHO, a few tens of Hertz will make no
noticable difference, but hundreds of Hertz difference in the BFOs will be
objectionable.)

Wayne - would it be possible to change the firmware to use the same BFO for
transmitting and receiving for all modes except SSB?  Or is my analysis
incorrect here?

73,
Don W3FPR


----- Original Message -----

> I participated in the 160 Meter CW contest this weekend with my K2/100 and
> noticed something I had never noticed before.  I think that I might have a
> misadjustment in the filters and I am not sure where.
>
> I would tune a station (S&P) to where I thought I was in the bandpass of
> the RC station.  At least the note sounded good to me.  Invariably, I
> would have to tune about a tenth of a KC down to actual make the contact.
> I could call on the higher tone and they would not hear me, but calling on
> the lower tone they would come back all the time.  I have the filter
> center set at 700 with filters widths at 1.5 - 700 - 400 - 100.
>
> Do I have something set to low or to high with the BFO?  This gets
> confusing to me.
>

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