DSP and CW?
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I operate mostly digital mode and use MixW to help decode contest CW
QSOs. Before I acquired the DSP2, I could adequately decode by machine only strong perfectly sent CW signals such as W1AW code practice transmissions using either my K2/100 or IC-735. After installation of the DSP2 NR, I noticed a great reduction in background hash improving the CW S/S+N ratio. The DSP2 made it possible for me to machine decode most contest CW QSOs. The DSP2 NR does alter the CW tone quality to a certain extent, but makes listening easier due to the reduction in background noise. Less aggressive settings improves tone quality, but also reduces background noise reduction. I do not like the DSP2 NR for SSB because of the watery quality it gives to voice. Reducing NR aggressiveness improves voice quality, but at the expense of background noise reduction. Very weak CW DX signals cannot be decoded by my machine, even with the NR on, but such signals are often clear enough to be decoded by ear with the NR set on. The NR does not help me much at very narrow audio filter settings, but seem to work well with wider settings. The audio filters of the DSP2 are excellant and do not slightly shift frequency between TX and RX like the K2 crystal filters. The slight frequency shift using XFil is only an issue for me when machine decoding. I usually operate CW with the AGC set off and the NR on controlling volume using RF gain. Turning the AGC off is very important for weak signal machine CW decoding. It appears to me that machine decoding of machine generated CW is improved when the background noise between dits and dahs has been well supressed with enough audio tone being present to activate the CW decoder. Hand sent code can be hard to decode by machine as it has less than perfect timing of dits, dahs, and spaces. The computer is no replacement for the trained human ear when it comes to copying CW. While weak hand sent DX CW may not be very copiable by machine, the DSP2 NR should help one manually copy weak hard to copy signals. I think that the DSP2 is a great asset but one should not expect weak signal miracles such as being able to hear and copy DX transmissions that are imperceptable with the NR off. The K2 DSP2 is the only DSP unit that I have used so I cannot compare it to other rigs and units. -----Original Message----- From: [hidden email] To: [hidden email] Sent: Thu, 29 Mar 2007 10:24 AM Subject: [Elecraft] DSP and CW? Does this combination make sense? I operate 100% CW. These days, I seem to be chasing a lot of very weak signals with questionable readability. My vertical isn't the quietest of antennas (they never are) and my neighborhood has a fair amount of QRM on 40m during "real people hours". ************** Snip ************** ________________________________________________________________________ AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Stephen W. Kercel
That is actually what I meant. I am very happy with the crystal filters. I want
the option of using them OR the DSP. I already know I like the crystal filters. But I expect to enjoy the DSP as well. Just want options. 73, Tom KG3V Quoting "Stephen W. Kercel" <[hidden email]>: > Tom: > > If you if you can toggle off all DSP processing entirely, the answer > is yes. What you cannot do is install both analog and digital audio > filtering in the same K2. > > 73, > > Steve Kercel > AA4AK > > > At 11:21 AM 3/29/2007, Tom Zeltwanger wrote: > >Interesting discussion as I am just getting ready to build the DSP unit. > Can > >you still use the "plain" audio CW filters once you install the DSP? This > DSP > >is extremely flexible and I can't image that each person couldn't get some > >settings that will be useful to them, although it may take some time. > > > >73, > > > >TOm KG3V > > > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by n6wg
Thanks Bob,
Now I have numerous options - which is the way I like it. I will be using this for mostly CW contesting, so I expect to use them all at times. 73, Tom KG3V Quoting Bob Tellefsen <[hidden email]>: > One additional thought. > It is not unusual to use an external AF filter with > headphones. I have a homebrew passive filter > that I put in line occasionally. It is not needed > so much for additional selectivity as to reduce > higher pitched white noise that comes through > along with signal. > You can buy these filters or just cobble your own > out of junkbox parts. > 73, Bob N6WG > > ----- Original Message ----- > From: "Tom Hammond" <[hidden email]> > To: "Tom Zeltwanger" <[hidden email]>; "Stephen W. Kercel" > <[hidden email]> > Cc: <[hidden email]> > Sent: Thursday, March 29, 2007 8:19 AM > Subject: Re: [Elecraft] DSP and CW? > > > > Tom: > > > > >Can you still use the "plain" audio CW filters once you install the > > >DSP? This DSP is extremely flexible and I can't image that each > > >person couldn't get some > > >settings that will be useful to them, although it may take some time. > > > > You can have only one (1) audio filter installed at a time, KAF2 or > > KDSP2, but not both, sorry. > > > > 73, > > > > Tom N0SS > > > > _______________________________________________ > > Elecraft mailing list > > Post to: [hidden email] > > You must be a subscriber to post to the list. > > Subscriber Info (Addr. Change, sub, unsub etc.): > > http://mailman.qth.net/mailman/listinfo/elecraft > > > > Help: http://mailman.qth.net/subscribers.htm > > Elecraft web page: http://www.elecraft.com > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by n6wg
>> suburban Palo Alto lot :-) No room for a beverage, and I think I'd
>> be lynched if I tried to put up a rotatable loop! Hi Chris, You can make a really neat and small rx loop out of copper pipe. I use one for VLF [currently listening to the 600m tests]. Mine is made out of `1/2" pipe, and is an octagon ... very easy to make with the 45 deg fittings. It is broken at the top so it isn't a continuous piece, and has a T-fitting at the bottom. I pulled a length of 8-pr in-premises telephone cable through it, and then tied the ends of the wires together to make a 16-turn loop. I use a variable cap to tune it. For 600m, I needed all three sections of a tuning cap out of an ancient TRF radio, but for 160, a single 365pf variable works. The noise null is really [really] sharp, and as long as that isn't where the station is too, the desired signal just pops up out of the noise for me. Mine is about 5' across, however I'm not sure it really matters a lot unless it gets really small. 73, Fred K6DGW - Northern California Contest Club - CU in the 2007 CQP Oct 6-7 - www.cqp.org _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Tom Zeltwanger
Tom:
Most certainly you CAN use the XFIL and DSP in tandem!!! Works nicely. 73, Tom Hammond N0SS At 05:09 PM 3/29/2007, you wrote: >That is actually what I meant. I am very happy with the crystal >filters. I want >the option of using them OR the DSP. I already know I like the >crystal filters. >But I expect to enjoy the DSP as well. Just want options. > >73, > >Tom KG3V _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Chris Kantarjiev K6DBG
Thanks for all the comments. I ordered a KDSP2 (and received notice that
it has shipped) and expect to have it in my K2 in time for my birthday next weekend :-) The discussion also seems to have pushed me over the edge on finally investigating small loop antennas. The prospect of putting any sort of rotating antenna outside is still difficult with my shack arrangement (well, controlling an outside antenna from the inside, that is), but I can see myself doing some experiments out at the feed through... I'll report back. 73 de chris K6DBG P.S. Thanks for the reminder of using a wide Xfil and the filter "between my ears". It definitely helps. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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