[Elecraft] K3 CW Rx Audio

Mon Apr 21 11:41:13 EDT 2008

Hi All,

I'm a little confused about who is saying what here.  If I read it right, 
Bill, W4ZV, is responding to Doug by quoting Fred!  Have I got it right?  In 
any event, I found this post to be very interesting.  I read it twice, in 
fact, because as I went through it the first time I started getting a strong 
feeling that this was something not to be taken lightly.  It seems to be 
very much like a "pearl" that comes from lots and lots of experience.

In any event, I am fortunate to have both the K3 and an Orion II, and I 
intend to try and duplicate Fred's described setup to see if I can achieve 
the effect he outlines, and to do it with both radios.  For one thing, I 
never use a tone as low as 400 hz.  I've always set my radios so that the 
received tone was in the 600 to 700 hz range.  Apparently, according to 
Fred, I may be doing it all wrong!  My reaction has always been that a lower 
tone seemed to sound too much like the background noise, so I set things 
higher.  Also, I'm not sure I've ever reached for the notch control to limit 
nearby QRM, unless it was hetrodyne type of interference.  Shame on me I 
think. This may be partly because I'm still somewhat married in my operating 
habits to the old notch technology which meant that using a notch on CW was 
counterproductive.  If the interference was anything other than a solid tone 
(i.e. hetrodyne), using the notch would cause the CW signal to be also 
notched.  Poof!  But newer technology, like that on the K3, allows you to 
notch out a variety of offenders without materially degrading the received 
CW signal.  Now, I know that, but for some reason I haven't taken full 
advantage of it.  This probably exposes the fact that I may not have read 
the manual sufficiently!  Now that I think about it, I can say that I have 
recently tinkered with the notch when trying to deal with the chinese radar 
on 40 meters, and with some success.  You might think this would have caused 
my hand to slap my forehead a bit harder!  Age has apparently numbed my 
brain more than I realized.

In my view, the QRM fighting tools of the K3 are superior to the Orion II 
(filters, notch, NB, etc.), so I'm thinking this could be a very interesting 
(and enlightening) experiment.  But it seems very likely I haven't operated 
either radio at their full potential.  I probably also need to reassess my 
complement of headphones!

Thanks to Bill for passing this tidbit along, and to Fred for authoring it.

Dave W7AQK

----- Original Message ----- 
From: "Bill W4ZV" <btippett at alum.mit.edu>
To: <elecraft at mailman.qth.net>
Sent: Sunday, April 20, 2008 3:44 PM
Subject: Re: [Elecraft] K3 CW Rx Audio

>
>
>
> DOUGLAS ZWIEBEL wrote:
>>
>> I can't, for the life of me, figure why anyone would want to listen to
>> cw with a really wide filter, but.....
>>
>
>>From K3ZO many time winner of Dayton pileup contests:
>
> I just got back from Thailand so am reading all of this old discussion
> for the first time, but as an
> Orion owner, and since someone mentioned me in a post, I thought I
> ought to comment.
>
> I have always preferred to use the filters between my ears rather than
> the ones that come
> with radios and never liked narrow filters because the ringing bothers
> me a lot.  N3UM and
> W4AU convinced me to go with the Orion mainly because they said it
> "doesn't ring."  Well
> in my opinion it does, but you can zero out the ringing by using a
> bandwidth of exactly
> 970 Hz, so when I'm on CW that's where my bandwidth is always set.
> Precisely because
> in a DX contest I had a loud W2 perch 670 Hz above me and used the
> Orion's very FB notch
> filter to notch him out, I now also use the notch filter set for 670
> Hz tone and 300 Hz bandwidth
> full time while on CW, because in the Orion the notch filter appears
> to the user to act like another filter in series with the regular one.
> This combination has given me reception pleasure like I
> haven't had for years (maybe my Drake R4C with the Sherwood mods got
> close way back when).
>
> Nevertheless taking Tom's main point, narrowing a filter mainly so you
> can squeeze up right close to another guy running on an adjacent
> channel is not a good reason to use a narrow filter.  In my experience
> you always want to know what is going on around you as you run.
> Narrowing the filter beyond a certain point deprives you of the audio
> version of peripheral vision, and you lose if you
> cut yourself off from what's going on around you that way.  Tom is
> right when he says that it will
> lower your rate even though you think you're really banging away.
>
> With a rig like the Orion the tone you set your sidetone monitor to is
> also very important.  I like to copy CW at 400 Hz, and I have been
> surprised when people have commented that 400 Hz is a much lower tone
> than they like to use.  I believe it is established science that the
> lower the tone you use to copy, the better your ear is at separating
> out tones which differ in frequency very
> little from each other.  I actually thought I was using a rather high
> choice of tone, as I recall
> some articles I read years ago, perhaps by professional ship-to-shore
> ops, advocating 200 or
> 300 Hz as their tones of choice.
>
> I also believe in using a first-class pair of headphones.  The
> arguments about "communications quality audio" vs "high fi audio" have
> never cut any mustard with me.  In 60 years of using all kinds of
> different receivers, speakers and headphones, I am of the firm belief
> that the ear wants to extract as much information as it can get from
> any receiving setup, meaning that whatever is the final
> apparatus used to translate electrons into sound, it should be as good
> as scientifically practical in transmitting the widest range of sounds
> with as flat a response as possible.  Therefore my German Sennheiser
> headset has pride of place in my shack.
>
> As those who are familiar with my views on the subject of people who
> are quick to send "QRL" can attest however, this does not mean that I
> allow  someone else to determine for me what my optimum receiving
> bandwidth should be.  When I started contesting in 1952 nobody ever
> talked about level playing fields or how someone stole your frequency.
> It was just assumed that if things got too hot for you, you moved.
> That was part of the game.  We have since shot ourselves in the foot
> by relegating our beginners to two meter FM  where they got the idea
> that all channels everywhere should be as crystal clear as the ones
> they got started with at the beginning.
>
> Back when men were men, a crowded band full of signals was a joy to
> behold, a challenge to be reckoned with and mastered.  I know this
> discussion has been mainly about CW, but the best example I can think
> of to illustrate this particular point was 75 meter phone on a winter
> night with
> the green tinge of aurora flickering on the northern horizon.  Yes, in
> the "AM days" the band on such a night would be filled with
> heterodynes from one end to the other -- we called it "jingle bells"
> -- and there were about three signals in the whole band that you could
> actually copy, and yet the presence of all those heterodynes meant
> there were sure a hell of a lot of us in there trying.
>
> Over the years we have been afforded the right to QSY at will within
> wide portions of spectrum
> of which most of our bands consist precisely because we have convinced
> our authorities that we, more efficiently than any other radio
> service, have demonstrated that we can share limited spectrum capably
> and get maximum production out of it.  Be careful how much you wish
> the QRM would just go away, the FCC's answer might be to duplicate the
> 60 meter experience on all our other bands.
>
> And if I sound like a nasty old codger, well, having just turned 70, I
> feel I have a right to act my age, and besides, if I don't comment
> now, I may never get another chance.
>
> Season's greetings to you all!
>
> 73, Fred, K3ZO
>
> -- 
> View this message in context: 
> http://www.nabble.com/K3-CW-Rx-Audio-tp16798925p16799865.html
> Sent from the Elecraft mailing list archive at Nabble.com.
>
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> 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
> 