Impossible mission? USB with the 13khz filter for PSK31 on Digipan
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Re: Impossible mission? USB with the 13khz filter for PSK31 on Digipan
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I don't use Digipan but I doubt if it is capable of displaying that big a slice of bandwidth. The maximum that can be received is half the sampling rate the software uses. Many of the older digimode programs use a sampling rate of 8KHz or 11.025KHz. So my first question is what sampling rate are you using? My second question is, what is the point anyway? All the PSK31 activity here takes place in a bandwidth of about 3KHz. So a 4KHz waterfall would show you all you wanted to see. If it covered any wider then stations operating close together would be hard to tell apart.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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I don't use Digipan but I doubt if it is capable of displaying that big a slice of bandwidth. The maximum that can be received is half the sampling rate the software uses. Many of the older digimode programs use a sampling rate of 8KHz or 11.025KHz. So my first question is what sampling rate are you using?
Thanks for the advice.....I am running at 12Khz, giving me a 6Khz receive limit on the computer...good point. Still, I can only get about 4Khz out of the K3 even though I have the 12Khz filter, and I wouldn't be surprised to find other software out there that will go much wider. My second question is, what is the point anyway? All the PSK31 activity here takes place in a bandwidth of about 3KHz. I guess a lot of the time that is true, but certainly during the PSK 31 contests things broaden out a bit. So a 4KHz waterfall would show you all you wanted to see. If it covered any wider then stations operating close together would be hard to tell apart. I don't understand what you mean by that. Why would they be harder to tell apart if I had more bandwidth? I don't want to run broadbandwidth all the time, just long enough to find somthing interesting and then I want to narrow down to 50Khz (I also have the 200hz filter) to peak it up. Actually, that brings up another point, I wish the filter shift would move in increments smaller than the current increment so that I could really zero in on psk31 signals, as they are so close sometimes, and I like to operate in the smallest bandwidth possible. Thanks again, Tom-N2YTF |
Re: Impossible mission? USB with the 13khz filter for PSK31on Digipan
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In reply to this post by Tom-N2YTF
> Unfortunately, despite specifically enabling the KFL3B-FM > 13Khz filter in USB mode, I cannot get 13Khz of bandwidth in > USB receive. As a matter of fact, I cannot seem to get much > more then 4Khz of receive in USB receive mode. You will not see more than 4 KHz of audio in any mode. The DSP includes a "brickwall" cut-off at 4200 Hz in SSB, DATA, AM and FM with a lower (2800 Hz) cutoff in CW. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Thomas Tumino > Sent: Thursday, January 29, 2009 12:59 PM > To: [hidden email] > Subject: [Elecraft] Impossible mission? USB with the 13khz > filter for PSK31on Digipan > > > Hi there, > > I am running my K3 with Digipan computer software on PSK 31. > I also have a full complement of 5 filters in the K3, with > the widest being the KFL3B-FM 13Khz filter. > > Because Digipan can receive many PSK signals at once > (Multichannel Window), I would like to set my K3 to receive > USB through the 13Khz filter. > > Unfortunately, despite specifically enabling the KFL3B-FM > 13Khz filter in USB mode, I cannot get 13Khz of bandwidth in > USB receive. As a matter of fact, I cannot seem to get much > more then 4Khz of receive in USB receive mode. I can get the > XFIL display to tell me I am receiving through the 13Khz > filter, but only about 4Khz of audio will pass through > (perhaps the DSP??). > > Am I missing something here, or is this just an oversight in > firmware design? Multichannel simultaneous receive of a > massive chunk of bandwidth is a great feature of Digipan that > I would love to take advantage of with my K3. > > Does someone know how to receive USB at a 13Khz bandwidth with the K3? > > 73, > Tom-N2YTF > _______________________________________________ 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 |
Re: Impossible mission? USB with the 13khz filter for PSK31on Digipan
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With LP-PAN and PowerSDR or Winrad you can open up the audio bandwidth (20Khz?) 73, Barry N1EU |
Re: Impossible mission? USB with the 13khz filter for PSK31on Digipan
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In reply to this post by Joe Subich, W4TV-4
LP Pan and WinRad are using the K3's IF, not the audio output from the K3.
------------------------- 73, Greg - AB7R Whidbey Island WA NA-065 On Thu Jan 29 11:02 , Barry N1EU sent: > > > >Joe Subich, W4TV-4 wrote: >> >> >> >>> Unfortunately, despite specifically enabling the KFL3B-FM >>> 13Khz filter in USB mode, I cannot get 13Khz of bandwidth in >>> USB receive. As a matter of fact, I cannot seem to get much >>> more then 4Khz of receive in USB receive mode. >> >> You will not see more than 4 KHz of audio in any mode. The >> DSP includes a "brickwall" cut-off at 4200 Hz in SSB, DATA, >> AM and FM with a lower (2800 Hz) cutoff in CW. >> > >With LP-PAN and PowerSDR or Winrad you can open up the audio bandwidth >(20Khz?) > >73, >Barry N1EU > >-- >View this message in context: http://n2.nabble.com/Impossible-mission--USB-with- >Sent from the Elecraft mailing list archive at Nabble.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 _______________________________________________ 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 Joe Subich, W4TV-4
_______________________________________________ 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 |
Re: Impossible mission? USB with the 13khz filter for PSK31on Digipan
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In reply to this post by Greg - AB7R
I didn't see that requirement in the original post's question: "Does someone know how to receive USB at a 13Khz bandwidth with the K3?" Actually, I tried it and it seems that PowerSDR is limited to 10Khz and Winrad less than that, so LP-PAN evidently won't get you there either at this time. 73, Barry N1EU |
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The K3 audio channel is designed for communications audio in a bandwidth
of 5 kHz or less. There are a number of reasons for this. Using the 13 kHz roofing filter doesn't change that. It does widen the IF passband and make the radio more susceptible to nearby, very strong signals. Think of it as a way to emulate the performance of high-IF radios with wide roofing filters :-) In addition, most PSK31 activity takes place in a 3 kHz or less window on most bands since that is what most SSB filters will pass in most radios. I almost always narrow the passband once I have a QSO in progress since a strong station coming on can activate the AGC and push down the signal I am trying to copy, or affect the soundcard input, etc. 73, Lyle KK7P _______________________________________________ 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 |
Re: Impossible mission? USB with the 13khz filter for PSK31on Digipan
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In reply to this post by Tom-N2YTF
> I wonder why they setup the radio that way....thats > a limiting factor when using programs like CW skimmer > which like Digipan decodes a 3Khz+ swath of CW stations > all at once...... It looks like DigiPan will run/display up to 5500 Hz - that doesn't seem to be a significant benefit above the K3's 4200 Hz limit. CW Skimmer requires separate I/Q sources in order to do broadband decoding and that's not available from the K3 audio interface (Line Out). I don't know the DAC clock rate is but if possible it would be nice to be able to sretch the response to 5500 or 6000 Hz for occasional use with AM/SWL/etc. However, I'd rather see per mode EQ and some extensions to the CAT interface first. 73, ... Joe, W4TV > -----Original Message----- > From: Thomas Tumino [mailto:[hidden email]] > Sent: Thursday, January 29, 2009 4:35 PM > To: [hidden email]; [hidden email] > Subject: RE: [Elecraft] Impossible mission? USB with the > 13khz filter for PSK31on Digipan > > > > Unfortunately, despite specifically enabling the KFL3B-FM > > 13Khz filter in USB mode, I cannot get 13Khz of bandwidth in > > USB receive. As a matter of fact, I cannot seem to get much > > more then 4Khz of receive in USB receive mode. > > You will not see more than 4 KHz of audio in any mode. The > DSP includes a "brickwall" cut-off at 4200 Hz in SSB, DATA, > AM and FM with a lower (2800 Hz) cutoff in CW. > > 73, > > ... Joe, W4TV > > Joe, > I wonder why they setup the radio that way....thats > a limiting factor when using programs like CW skimmer > which like Digipan decodes a 3Khz+ swath of CW stations > all at once...... > 73-Tom-N2YTF > > > > > > -----Original Message----- > > From: [hidden email] > > [mailto:[hidden email]] On Behalf Of Thomas Tumino > > Sent: Thursday, January 29, 2009 12:59 PM > > To: [hidden email] > > Subject: [Elecraft] Impossible mission? USB with the 13khz > > filter for PSK31on Digipan > > > > > > Hi there, > > > > I am running my K3 with Digipan computer software on PSK 31. > > I also have a full complement of 5 filters in the K3, with > > the widest being the KFL3B-FM 13Khz filter. > > > > Because Digipan can receive many PSK signals at once > > (Multichannel Window), I would like to set my K3 to receive > > USB through the 13Khz filter. > > > > Unfortunately, despite specifically enabling the KFL3B-FM > > 13Khz filter in USB mode, I cannot get 13Khz of bandwidth in > > USB receive. As a matter of fact, I cannot seem to get much > > more then 4Khz of receive in USB receive mode. I can get the > > XFIL display to tell me I am receiving through the 13Khz > > filter, but only about 4Khz of audio will pass through > > (perhaps the DSP??). > > > > Am I missing something here, or is this just an oversight in > > firmware design? Multichannel simultaneous receive of a > > massive chunk of bandwidth is a great feature of Digipan that > > I would love to take advantage of with my K3. > > > > Does someone know how to receive USB at a 13Khz bandwidth > with the K3? > > > > 73, > > Tom-N2YTF > > > _______________________________________________ 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 |
Re: Impossible mission? USB with the 13khz filter for PSK31on Digipan
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In reply to this post by Barry N1EU
On Thu, Jan 29, 2009 at 11:02 PM, Leigh L. Klotz, Jr. WA5ZNU
<[hidden email]> wrote: > Since PowerSDR was origianally designed for the even wider SDR devices, > I'd expect that it would be able to show you more than 10Khz. Maybe it's > a setting? Perhapshe LP-PAN yahoo group would be the place to look. > Leigh, we're talking about audio output, not panadapter diplay width. Besides a panadapter display, the LP-PAN software will demodulate any displayed signal under user control and provide demodulated audio output. 73, Barry N1EU _______________________________________________ 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 Joe Subich, W4TV-4
_______________________________________________ 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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> Typical FM bandwidth is 5Khz, so the DSP really needs to be changed as
> in its current state the K3 is chopping off 1Khz of received signal in > FM, or 20% of the bandwidth. There is more than one FM standard in use in Amateur radio around the globe. In some parts of the U.S., 2 meter channels are on 20 kHz spacing, some are on 15 kHz spacing. In some parts of the world, channels are 12.5 kHz apart, or moving towards 12.5 kHz spacing. The rule of thumb for FM signals is that the bandwidth is (2 * deviation) + Fmod where Fmod is the highest audio frequency. This is an oversimplification, but serves to illustrate the idea. In the K3 we have a 13 kHz wide IF filter. By limiting deviation to 4.5 kHz and Fmod to 3 kHz, we occupy about 12 kHz. If we allowed 5 kHz audio and 5 kHz deviation, we'd occupy 15 kHz. Such operation leaves no room for frequency error or adjacent channel rejection in a 15 kHz channel region. By limiting the audio response to about 3 kHz, we ensure that we are compatible with existing channels and will be compatible with future narrower channels. In the case of AM, we will be increasing the upper audio frequency response. 73, Lyle KK7P _______________________________________________ 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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No, Carson's rule is occupied bandwidth = 2*(deviation + maximum
modulating frequency) For 5 KHz deviation and 3 KHz highest modulating frequency, bandwidth is 16 KHz. For 4.5 KHz and 3 KHz, it's 15 KHz, not 13. Jack K8ZOA Lyle Johnson wrote: >> Typical FM bandwidth is 5Khz, so the DSP really needs to be changed as >> in its current state the K3 is chopping off 1Khz of received signal in >> FM, or 20% of the bandwidth. >> > > There is more than one FM standard in use in Amateur radio around the > globe. In some parts of the U.S., 2 meter channels are on 20 kHz > spacing, some are on 15 kHz spacing. In some parts of the world, > channels are 12.5 kHz apart, or moving towards 12.5 kHz spacing. > > The rule of thumb for FM signals is that the bandwidth is (2 * > deviation) + Fmod where Fmod is the highest audio frequency. This is an > oversimplification, but serves to illustrate the idea. > > In the K3 we have a 13 kHz wide IF filter. By limiting deviation to 4.5 > kHz and Fmod to 3 kHz, we occupy about 12 kHz. > > If we allowed 5 kHz audio and 5 kHz deviation, we'd occupy 15 kHz. Such > operation leaves no room for frequency error or adjacent channel > rejection in a 15 kHz channel region. > > By limiting the audio response to about 3 kHz, we ensure that we are > compatible with existing channels and will be compatible with future > narrower channels. > > In the case of AM, we will be increasing the upper audio frequency response. > > 73, > > Lyle KK7P > > > _______________________________________________ > 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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Hello Jack!
> No, Carson's rule is occupied bandwidth = 2*(deviation + maximum > modulating frequency)... You are correct. Thank you for pointing this out. This is all the more reason why we can't increase the FM audio passband. In fact, we limit the upper end to 2.8 kHz and rapidly roll off response to higher frequency audio components. Fortunately, even with pre-emphasis, the highest frequency components of a typical voice don't have a lot of energy at the highest frequencies, so the resulting occupied bandiwdth is probably a little less. Those of our customers in areas with tight channel spacing need to reduce their deviation consistent with common Amateur FM practice in their area. Use CONFIG:FM DEV to set the peak deviation. 73, Lyle KK7P _______________________________________________ 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 KK7P
This is good news Lyle. I've been starting to enjoy what a great SWL radio the K3 is and a little more bandwidth will make it even greater! 73, Barry N1EU |
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On Jan 30, 2009, at 1:11 PM, Barry N1EU wrote: > Lyle Johnson wrote: >> >> In the case of AM, we will be increasing the upper audio frequency >> response. >> > This is good news Lyle. I've been starting to enjoy what a great SWL > radio > the K3 is and a little more bandwidth will make it even greater! Meanwhile, try using SSB to copy AM signals. This uses the same crystal filter (6 kHz) but allows for around 4 kHz of AF bandwidth. 73, Wayne N6KR --- 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 KK7P
Lyle, others ...
I'm a career two-way radio tech. I've been in the midst of amateur radio VHF/UHF FM since (almost) the beginning. The first 2M repeater in Florida was built in my shop. I've been Montana's frequency coordinator for 30+ years. In short, I think I'm qualified to enter into the FM deviation discussion. The industry's deviation standard is 4.5 kHz for today's 15 kHz channel spaced radios. Yes, there is a move to 12.5 kHz channel spacing in some services, but these (mostly) use "digital" techniques, and I don't for see this impacting any K3 users. Please consider this (+/- 4.5 kHz deviation) standard for the K3's FM mode. FWIW, when measured on Motorola's latest / greatest service monitor, my K3's (S/N 56 with a KFL3B FM filter and Ver. 2.80) transmitter deviates +/- 5.0 kHz on 52.525 with a menu setting of 4.0 kHz deviation. This is while using a "robust", sustained "F-o-u-r". (:-)) I didn't measure it on 10M FM. I won't enter into any discussion about ESSB, except to say most view a (transmitted) AM or SSB bandwith signal over 4.0 kHz wide to be excessive, discourteous and "not in good amateur practice". 73! Ken Kopp - K0PP _______________________________________________ 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 wayne burdick
On Fri, Jan 30, 2009 at 9:45 PM, wayne burdick <[hidden email]> wrote:
> > On Jan 30, 2009, at 1:11 PM, Barry N1EU wrote: > >> Lyle Johnson wrote: >>> >>> In the case of AM, we will be increasing the upper audio frequency >>> response. >>> >> This is good news Lyle. I've been starting to enjoy what a great SWL >> radio >> the K3 is and a little more bandwidth will make it even greater! > > Meanwhile, try using SSB to copy AM signals. This uses the same crystal > filter (6 kHz) but allows for around 4 kHz of AF bandwidth. Thanks Wayne. Yes, I do that sometimes! I also sometimes listen with K3/LP-PAN/Winrad because the 5.5Khz AF and sync detector combo make for real listening pleasure. I'd love an excuse to spring for a 13Khz roofing filter ;-) 73, Barry N1EU _______________________________________________ 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 Ken Kopp-3
Except that you did enter into the discussion of course. Why is
bandwidth over 4Khz "not in good amateur practice" or discourteous on a warm Sunday afternoon when there are all of 3 or 4 stations within hearing on 75 or 160, or when 20 is otherwise mostly deader than a doorknob? These generic statements presume that if the radio gives someone the possibility of a wider bandwidth, that it will be used at 9:00pm local on 75M -- not that the guys overdriving their amps on that band are a problem :-) So why restrict it in the radio? Why should the manufacturer of the radio be compelled to make someone's version of a "politically correct" decision? Makes no sense. It's no different than arguing that there should be a 55 (or even 65) mph governor on the car you drive, Don't think that would go over so well, even for those who mostly putt along in town at 45 in 25 MPH zones :) My personal opinion? Too many people are too used to living in CCR controlled neighborhoods, and just presume that the color of their front door is somehow a "group" decision :-) Grant/NQ5T On Jan 30, 2009, at 4:41 PM, Ken Kopp wrote: > L > I won't enter into any discussion about ESSB, except to say > most view a (transmitted) AM or SSB bandwith signal over > 4.0 kHz wide to be excessive, discourteous and "not in good > amateur practice". > > 7 _______________________________________________ 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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