[Elecraft] Err TXF

[Julian G4ILO]

OK. If that's the case, we were barking up the wrong tree here.

I've just done Spectrogram plots of band noise through the 2.7KHz
filter with the DSP opened up to max. They are at
www.g4ilo.com/images/usb.gif and www.g4ilo.com/images/lsb.gif if
anyone is interested to look at them. They look pretty similar except
the skirt widens out at about 20db down on the HF side, and there is
more high frequencies getting through on LSB than USB, which I can
hear. The bandwidth at -6dB down certainly looks wider than 2.4KHz.

I can't see a difference that explains why LSB and USB don't sound the
same to me when monitored on-air. I've monitored the transmission
using both the K2 (which isn't really a good tool for this since its
opposite sideband responses aren't identical either) and the FT-817
which has a fairly wide standard SSB filter and sounds the same on
either sideband.

-- 
Julian, G4ILO
QRP Station: Elecraft K3 #222; K2 #392
G4ILO's Shack: www.g4ilo.com


On 17/01/2008, Greg - AB7R <ab7r at cablespeed.com> wrote:
> I think this is moot when it comes to TX.  As mentioned by Bill, you can ONLY use
> the 2.7 or 2.8 for the TX filter in all modes except for AM, that requires the 6
> kHz filter for TX (for now).  Setting the BW in CONFIG for either the 2.8 or 2.7
> filter is not altering the filter, rather it determines when that roofing filter
> turns on in relation to adjusting the DSP Filter width with the front panel DSP
> controls.  If you set the 2.8 at 2.8 and adjust the DSP controls from say 3.0 kHz
> down to 2.4 kHz, the 2.8 will kick in when the DSP filter is set for 2.8.
> If you set the 2.8 filter BW in CONFIG as 2.6 kHz, then the 2.8 filter will not
> come on until the DSP BW is set to 2.6 kHz.
>
> So if you have the 2.8 set at say FL2, then you set the TX filter as FL2 for all
> modes except AM.  Setting the BW in CONFIG to a lesser value should not affect TX.
>
>
> -------------------------
> 73,
> Greg - AB7R
> Whidbey Island WA
> NA-065
> K3#0009
>
> On Thu Jan 17  6:04 , G4ILO  sent:
>
> >
> >
> >
> >Bill W4ZV wrote:
> >>
> >> I seriously doubt it since the 5-pole has been measured at >2.9 kHz (6 dB
> >> BW).  It's easy enough to check without unnecessary speculation.
> >>
> >Unnecessary speculation? Unnecessary as far as you are concerned, perhaps,
> >but not for me. The figures quoted in the Wiki weren't obtained by measuring
> >*my* filter. And I don't have the equipment to easily check it. What else
> >might the "2.39KHz" mean?
> >
> >-----
> >Julian, G4ILO K2 s/n: 392  K3 s/n: 222
> >G4ILO's Shack: www.g4ilo.com
> >Zerobeat Ham Forums: www.zerobeat.net/smf
> >--
> >View this message in context: http://www.nabble.com/Err-TXF-on-7.077-
> tp14532160p14919276.html
> >Sent from the Elecraft mailing list archive at Nabble.com.
> >
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