IF shift
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Hey friends, how hard would it be to implement something along the
lines of an IF shift, ala the TS830S IF shift? That's something I really like about my 830 and it seems like it would be a nice addition to the K2. Along the same lines, would it be feasible to have an outboard S-meter needle? I guess I'm somewhat old fashioned :) I do have the DSP module in my K2, and I guess I could achieve similar results with that, yes? It's just that it's not a simple knob to turn... Thanks for any thoughts, Jeff _______________________________________________ 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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What is the point of IF shift? What purpose does it serve? Can't you do the same thing (or nearly so) with RIT? My understanding of IF shift is that it allows you to move an interfering signal to the edge of the passband and attenuate it by doing so. Seems that nearly the same result can be achieved with RIT. Please correct me if I'm wrong on this. 73 de dave ab9ca Jeff Kinzli wrote: > Hey friends, how hard would it be to implement something along the > lines of an IF shift, ala the TS830S IF shift? That's something I > really like about my 830 and it seems like it would be a nice addition > to the K2. > > Along the same lines, would it be feasible to have an outboard S-meter > needle? > > I guess I'm somewhat old fashioned :) > > I do have the DSP module in my K2, and I guess I could achieve similar > results with that, yes? It's just that it's not a simple knob to > turn... > > Thanks for any thoughts, > > Jeff > _______________________________________________ > 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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dave wrote:
> > What is the point of IF shift? What purpose does it serve? > > Can't you do the same thing (or nearly so) with RIT? > > My understanding of IF shift is that it allows you to move an > interfering signal to the edge of the passband and attenuate it by doing > so. Seems that nearly the same result can be achieved with RIT. Please > correct me if I'm wrong on this. > > 73 de dave > ab9ca Timing is everything, I just logged on and there was your question. IF shift [a la the TS830] moves the signals in the passband but does not change their pitch. RIT moves them, but their pitch changes. I sold my TS830 with IF shift, and I do miss it on the TS850 and K2 [although the K2 filters are so good, they tend to make up for it a little]. IF Shift [aka passband tuning from the Collins days] is cool on CW, and fantastic on RTTY. Art Collins achieved it in the 75A4 by actually rotating the entire PTO assembly to keep the received pitch the same. Now days it's done with magic. 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 Jeff Kinzli
One of the strengths of the K2 is its single-conversion design. That is, in
part, responsible for the extremely good specifications the receiver enjoys. However, i.f. shift such as other rigs often feature require a multiple-conversion design with all the issues that come with additional mixers, oscillators and complexity. Even so, you can enjoy i.f. shift with the K2. It's not as flexible as the multiple-conversion receivers use, but it does a FB job for me. Simply set up for different i.f. bandpass positions on your four XFIL filter positions. Remember that FL1 is always used for transmit, so that one must be set for the best transmit audio quality; its position will be set, in part, by your voice and the microphone you use. Even so, you'll probably find it's the best general-purpose position for receive too. Now you can set the other filters to put the passband closer to or farther from the carrier frequency as you desire. I have one position set closer to the carrier frequency for SWL-ing, since that provides better bass response on broadcast signals. You don't even have to use the OPT1 filter for the other positions, if you want a "tighter" bandwidth. You can use adjustable-bandwidth filters and crank one down tight for minimum bandpass and set it according to your tastes. Now, when you encounter a weak or QRM-ridden signal, you can select between the four different filter and filter settings by pressing the XFIL button. Ron AC7AC -----Original Message----- Hey friends, how hard would it be to implement something along the lines of an IF shift, ala the TS830S IF shift? That's something I really like about my 830 and it seems like it would be a nice addition to the K2. Along the same lines, would it be feasible to have an outboard S-meter needle? I guess I'm somewhat old fashioned :) I do have the DSP module in my K2, and I guess I could achieve similar results with that, yes? It's just that it's not a simple knob to turn... Thanks for any thoughts, Jeff _______________________________________________ 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 Jeff Kinzli
Jeff,
IF shift is practical in multiconversion receivers, but the K2 is a single conversion design (for fewer spurs, better dynamic range and better IMD). To implement IF shift in a single conversion receiver would mean changing the BFO in sync with the VFO - and that is not an easy feat. It might be practical in a one-band, one sideband receiver, but I don't think you would want to sacrifice your multiband K2 just to have IF shift. If you wish to extend the principle to both sidebands or to additional bands, the scheme gets complex. Yes, a larger microprocessor could possibly do that, but there are other requests for added functions when (and if) more storage space is available - due to the complexity of IF shift in a single conversion design, I would believe that is WAY down on Wayne's list of 'things to do'. 73, Don W3FPR > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]]On Behalf Of Jeff Kinzli > Sent: Wednesday, February 07, 2007 6:50 PM > To: [hidden email] > Subject: [Elecraft] IF shift > > > Hey friends, how hard would it be to implement something along the > lines of an IF shift, ala the TS830S IF shift? That's something I > really like about my 830 and it seems like it would be a nice addition > to the K2. > > Along the same lines, would it be feasible to have an outboard > S-meter needle? > > I guess I'm somewhat old fashioned :) > > I do have the DSP module in my K2, and I guess I could achieve similar > results with that, yes? It's just that it's not a simple knob to > turn... > > Thanks for any thoughts, > > Jeff > _______________________________________________ > 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 > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.432 / Virus Database: 268.17.29/673 - Release Date: > 2/6/2007 5:52 PM > No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.29/673 - Release Date: 2/6/2007 5:52 PM _______________________________________________ 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 dave-281
Dave and Jeff,
Dave you are right in saying that that both IF Shift and RIT (or even the main tuning knob) can be used to move an interfering signal out of the IF passband. The advantage of IF Shift is that the 'beat note' from / of the signal you want does not change as you move the interfering signal, but when using RIT it will change just as it would when tuning the receiver. This means that if RIT is used to get rid of the interfering signal the audio beat note from the wanted signal could change enough to make it necessary to bypass any narrow audio filter used for CW reception, assuming that the receiver does not have a BFO whose frequency can be changed using a front panel control to maintain the beat note at a fixed value. The required circuitry for IF Shift exists within the K2, but I imagine that the required changes to the firmware would determine whether or not the circuits could be used in this way. Jeff, I think that an outboard S meter would be quite feasible if the K2's AGC does not drift. 73, Geoff GM4ESD ----- Original Message ----- From: "dave" <[hidden email]> To: <[hidden email]> Sent: Thursday, February 08, 2007 12:07 AM Subject: Re: [Elecraft] IF shift > > What is the point of IF shift? What purpose does it serve? > > Can't you do the same thing (or nearly so) with RIT? > > My understanding of IF shift is that it allows you to move an interfering > signal to the edge of the passband and attenuate it by doing so. Seems > that nearly the same result can be achieved with RIT. Please correct me > if I'm wrong on this. > > 73 de dave > ab9ca _______________________________________________ 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 Jeff Kinzli
Jeff and gang,
If you're working CW, don't forget about the CW-Reverse feature of the K2. This feature accomplishes the same thing as IF shift, although the degree of passband frequency shift isn't adjustable in real time. 73 & 72, Jeff WB5GWB Long Island, NY _______________________________________________ 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 Jeff Kinzli
In the article from the contester on the Elecraft site, N6 something, he
setup the SSB filters to act a bit like an IF shift. One filter to the left, one to the right, and one center. Thought that was interesting. David Wilburn [hidden email] K4DGW Jeff Kinzli wrote: > Hey friends, how hard would it be to implement something along the > lines of an IF shift, ala the TS830S IF shift? That's something I > really like about my 830 and it seems like it would be a nice addition > to the K2. > > Along the same lines, would it be feasible to have an outboard S-meter > needle? > > I guess I'm somewhat old fashioned :) > > I do have the DSP module in my K2, and I guess I could achieve similar > results with that, yes? It's just that it's not a simple knob to > turn... > > Thanks for any thoughts, > > Jeff > _______________________________________________ > 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 Jeff Kinzli
David Wilburn wrote:
> In the article from the contester on the Elecraft site, N6 something, he > setup the SSB filters to act a bit like an IF shift. One filter to the > left, one to the right, and one center. Thought that was interesting. ------------------------------------------------------------------ Very interesting. I would guess that the result would be rather like two dimensional binaural reception if I understand left, right and center correctly. Did the article appear on this Reflector? 73, Geoff GM4ESD _______________________________________________ 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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This article had a big impact on my choice of the rig. It was written
from the user's point of view, and with extensive hands on experience. http://www.elecraft.com/TechNotes/ncjk2100.pdf David Wilburn [hidden email] K4DGW Geoffrey Mackenzie-Kennedy wrote: > David Wilburn wrote: > >> In the article from the contester on the Elecraft site, N6 something, >> he setup the SSB filters to act a bit like an IF shift. One filter to >> the left, one to the right, and one center. Thought that was >> interesting. > > > ------------------------------------------------------------------ > > Very interesting. I would guess that the result would be rather like > two dimensional binaural reception if I understand left, right and > center correctly. Did the article appear on this Reflector? > > 73, > Geoff > GM4ESD > > > _______________________________________________ > 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 Ron D'Eau Claire-2
Hi Ron
"One of the strengths of the K2 is its single-conversion design. That is, in part, responsible for the extremely good specifications the receiver enjoys. However, i.f. shift such as other rigs often feature require a multiple-conversion design with all the issues that come with additional mixers, oscillators and complexity. " Well, I'm not sure this is totally true. Before I got my first K2, I used a Kenwood TS-180S which had a very nice IF shift feature. It was also a single conversion radio, with an IF of about 8.3 MHz. I loaned the manual to Eric and Wayne so they could see how it was done. Sure wish there was a way to implement it in the K2. 73, Bob N6WG The Little Station with Attitude _______________________________________________ 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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Bob,
With due respect to Ron, IF Shift is very easy to design into a single conversion receiver with a selective IF filter *provided* that the IF to Audio detector is some form of mixer with BFO injection, such as a product detector. It would probably be difficult to implement in the K2 not because of the required circuits, which are already there, but because of the firmware changes and related alignment problems. Also the control needs to be manual on the front panel, not via some menu. 73, Geoff GM4ESD ----- Original Message ----- From: "Bob Tellefsen" <[hidden email]> To: "Ron D'Eau Claire" <[hidden email]>; "'Jeff Kinzli'" <[hidden email]>; <[hidden email]> Sent: Thursday, February 08, 2007 4:40 PM Subject: Re: [Elecraft] IF shift > Hi Ron > > "One of the strengths of the K2 is its single-conversion design. That is, > in > part, responsible for the extremely good specifications the receiver > enjoys. > However, i.f. shift such as other rigs often feature require a > multiple-conversion design with all the issues that come with additional > mixers, oscillators and complexity. " > > Well, I'm not sure this is totally true. Before I got my first K2, I used > a > Kenwood TS-180S which had a very nice IF shift feature. It was also a > single conversion radio, with an IF of about 8.3 MHz. I loaned the manual > to Eric and Wayne so they could see how it was done. > > Sure wish there was a way to implement it in the K2. > 73, Bob N6WG > The Little Station with Attitude _______________________________________________ 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
Hi, Bob:
Yes, I have learned about that one since posting my comment! I tend to forget that controllers today can do things that were not practical a few years ago. Stuart (I think it was) pointed out that Art Collins actually accomplished passband tuning by mechanically rotating the whole oscillator assembly in one of his designs. All of these approaches add complexity. Complexity isn't necessarily bad, but it's almost always more expensive either to design or to reproduce. Ron AC7AC -----Original Message----- Hi Ron "One of the strengths of the K2 is its single-conversion design. That is, in part, responsible for the extremely good specifications the receiver enjoys. However, i.f. shift such as other rigs often feature require a multiple-conversion design with all the issues that come with additional mixers, oscillators and complexity. " Well, I'm not sure this is totally true. Before I got my first K2, I used a Kenwood TS-180S which had a very nice IF shift feature. It was also a single conversion radio, with an IF of about 8.3 MHz. I loaned the manual to Eric and Wayne so they could see how it was done. Sure wish there was a way to implement it in the K2. 73, Bob N6WG The Little Station with Attitude _______________________________________________ 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 Jeff Kinzli
Morning Dale,
Passband Tuning can be incorporated into a single conversion receiver which uses a product detector. The method used in most commercial receivers for amateur use (putting aside DSP) is to have two IF filters in cascade along with mixers. By varying the injection frequencies to these mixers the passband of one filter can be made to 'slide over' the passband of the second filter thus changing the overall IF bandwidth. The input and output signal frequencies are sometimes kept to be the same, sometimes not. It is desireable to do this early on in the receiver chain, but it has been achieved in an outboard addition using audio input. If you view a single conversion receiver which uses a product detector as a dual conversion receiver with the second IF being at audio, then you will see the makings for Passband Tuning and IF Shift are there. The second IF filter required for Passband Tuning would be a good audio filter with steep skirts, although audio DSP might help here if its intermod performance is good. Please understand that I am risking some oversimplifications for the sake of Reflector bandwidth. The problem with implementing anything extra into the K2 which involves tight control over the LO (VCO) and BFO frequencies is, I understand, the firmware. This could be the deciding factor. 73, Geoff GM4ESD Dale WC7S wrote on Friday, February 09, 2007 at 12:21 AM: I would like to have a way to "adopt" a circuit for passband tuning, similar to what was in the Drake R4B or in the Icom 761. What would be involved to incorporate something in that area? Is it a non-item, from the view of single conversion? Thanks, Dale --... ...-- Dale - WC7S in Wy _______________________________________________ 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 Jeff Kinzli
N7XY queried:
>"One of the strengths of the K2 is its single-conversion design. That is, in >part, responsible for the extremely good specifications the receiver enjoys. >However, i.f. shift such as other rigs often feature require a >multiple-conversion design with all the issues that come with additional >mixers, oscillators and complexity. " > >Well, I'm not sure this is totally true. Before I got my first K2, I used a >Kenwood TS-180S which had a very nice IF shift feature. It was also a >single conversion radio, with an IF of about 8.3 MHz. I loaned the manual >to Eric and Wayne so they could see how it was done. > >Sure wish there was a way to implement it in the K2. TS-820S is another example of single conversion with IF shift. You can do with K2, but bit too granular with current front panel interface. I believe it is even mentioned in the manual. Making a knob into interface for IF shift is entirely possible, since knobs are already used as interface to change frequencies of stuff inside. "Firmware says no" (apologies to Little Britain ;^) Saying it can't be done & not appreciating what IF shift is good for probably helps keep it that way. ;^( 73 & HLNY, VR2BrettGraham _______________________________________________ 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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Brett, that quote was from N6WG, not me.
73, Bob, N7XY On Feb 9, 2007, at 3:57 PM, VR2BrettGraham wrote: > N7XY queried: > >> "One of the strengths of the K2 is its single-conversion design. >> That is, in >> part, responsible for the extremely good specifications the >> receiver enjoys. >> However, i.f. shift such as other rigs often feature require a >> multiple-conversion design with all the issues that come with >> additional >> mixers, oscillators and complexity. " >> >> Well, I'm not sure this is totally true. Before I got my first >> K2, I used a >> Kenwood TS-180S which had a very nice IF shift feature. It was >> also a >> single conversion radio, with an IF of about 8.3 MHz. I loaned >> the manual >> to Eric and Wayne so they could see how it was done. >> >> Sure wish there was a way to implement it in the K2. > > TS-820S is another example of single conversion with IF shift. > > You can do with K2, but bit too granular with current front panel > interface. I believe it is even mentioned in the manual. > > Making a knob into interface for IF shift is entirely possible, > since knobs are already used as interface to change > frequencies of stuff inside. > > "Firmware says no" (apologies to Little Britain ;^) > > Saying it can't be done & not appreciating what IF shift > is good for probably helps keep it that way. ;^( > > 73 & HLNY, VR2BrettGraham > > _______________________________________________ > 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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