[Elecraft] considering K3 purchase; choosing filters

[Jack Brabham]

  Rich,

I have similar use profile on my K3,   except I contest mostly on SSB 
and am trying to learn the ropes on RTTY in the interest getting into 
digital contesting.

On mine, K3 #4165, I have the 6kc mostly because I like to do a little 
SWLing, the 2.7 because so far I haven't justified the expense of 
upgrading it to the 2.8, and the 1.8.   For me, with poor hearing at 
high frequencies, the 1.8 seems to be a perfectly good day to day SSB 
filter.  My TS-850 had intelligibility issues with 1.8's in both IFs but 
on the K3 this filter  works just fine for general purpose SSB.   For my 
purposes I would like to trade it for a 1.5 since I find the 
intelligibility still good with the DSP cranked down to 1.5.

I haven't bought digital filters yet but am pretty much settled on the 8 
pole 500 and 8 pole 250 from INRAD.   Some of the digital modes I dabble 
in are 500hz wide so that pretty much rules out the 400 ( besides being 
too close to the 250).

The 1.0 seems like an orphan, it's too wide for any digital contesting 
and to narrow for SSB.   For casual digital usage the stock 2.7 with the 
DSP narrowed to suit is more than adequate.  I sometimes use the 6kc 
filter and get 4kc on the waterfall for PSK browsing.

73 Jack KZ5A


On 9/7/2010 2:33 PM, Richard Lee wrote:
> Hello all,
>
> I'd appreciate some advice as to several matters of interest as I seriously
> consider purchase of a K3. I have posted on and looked at the K3 Yahoo site
> in
> this regard as well as gotten some suggestions from other K3 owners. I am
> presently using an Omni 6+, a US Interface Navigator, and an old AL-80A amp.
> I operate almost exclusively cw, and enjoy some contesting. I very
> occasionally like to dabble in SSB contests. I also occasionally work some
> PSK31. I like N1MM, HRD, and the DX Lab suite. I am about to switch to Win7
> 64 bit OS.
>
> First, I cannot afford the second RX. (I am not a 'big gun' contester
> anyhow,
> and am not presently interested in contesting with two receivers.) I was
> contemplating the following EIGHT-pole filters: 2.8, 1.8 (or 1.5), 1.0 (or
> maybe not if I got the 1.5), .5 (or .4), and .25. I have heard from some
> that the 1.8 or 1.5 does just fine for SSB contesting (particularly in
> conjunction with the high cut or SHIFT). Unless I'm mistaken, both these
> filters are spec'd at 1.6 : 1 shape factor. I must say I am a bit worried
> about the 1.5, especially, as being too narrow for good intelligibility.
> However, if I opted for the 1.5, I might forego the 1.0 (which I
> contemplated using for casual cw operation) and save some money. I've been
> persuaded by comments on the Yahoo K3 group site that the EIGHT-pole 400 and
> 250 Hz filters are so close in bandwidth that it makes little sense to get
> both. I have thus been considering the Inrad EIGHT-pole 500 Hz filter and
> the EIGHT-pole 250 Hz filter. I like to run in cw contests when I can (40 is
> my favorite band), and I find I am bothered sometimes by strong stations
> starting up several hundred Hz from my established run frequency. As to the
> .5 Inrad filter, does anyone know whether that comes with the exact same
> board as Elecraft uses for, say, the 400 Hz filter? I appreciate your
> advice.
>
> On another topic, my computer has a com port, but no sound card (rather a
> VIA
> VT2010 chip on the motherboard); I was under the impression that I could
> dispense with the Navigator for interfacing the K3 with the computer and the
> software I like to use (as detailed above). Am I right about this? or will I
> need (or benefit from continuing) to use my Navigator?
>
> Thanks for any input/ comments.
>
> 73,
> -Rich, W2EG
>
>
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