[Elecraft] IF Shift, PB Tuning, and why neither completely eliminates QRM
These terms are often used interchangeably. It's like the terms "biannual" and "semi-annual." One is supposed to mean "every six months" and the other "every other year," but some dictionaries list them as synonyms, because you can make a case for either word having either definition. Similarly, there's nothing about either the term "I.F. Shift" or "Passband Tuning" that helps the average operator tell which one you're talking about. They're too vague. But there really are two different concepts here. I'll explain what I think they are, and then explain why most implementations don't really protect you against out-of-band signals. There are at least two kinds of "shifting" covered by these terms: - In one case you're just shifting the pitch of the I.F. without changing the bandwidth. A more accurate term would be "Pitch Shifting." - In the other case you're shifting *two* I.F.s in opposite directions, reducing the degree of I.F. filter overlap from 100% to something lower, so that the ultimate bandwidth (at audio) is reduced. The center pitch of the passband may or may not change at the same time. Let's call this "Filter Shifting." Either approach may appear to reduce QRM. But the QRM may in fact still be there. How can this be? It's because the bandwidth first filter has not actually changed; you're just listening to the portion of its passband that's making it through to the second I.F. The rest of the first I.F. filter's passband is still there, exposing subsequent stages to overload, AGC pumping, etc. That's why some seemingly modern radios break down in contest situations: they use a fairly wide first filter (often without telling you), then tighten or shift the *second* I.F. filter, which you perceive as a reduced bandwidth. But if a signal within the first passband exceeds the signal-handling capability of a subsequent stage, it sounds like, well--crap. (That's another name for serious in-band IMD.) A much better approach to the "Filter Shifing" problem would be to actually *narrow* the first crystal filter, protecting all subsequent stages. This is why the K2's variable-passband filter is such a great tool. You can narrow it down at the same time you narrow the DSP or audio filter. Of course the variable-passband filter is most useful in CW mode because it's optimized for narrow bandwidths, but it can certainly be used in SSB modes as well. In the case of the K2, ignoring audio filtering, the "quantized" version of I.F. shift that I mentioned earlier (using different BFO settings with the same crystal filter) is like the "Pitch Shifting" case. However, as soon as the pitch-shifted passband starts to hit a wall (namely the basic audio response of the radio and/or the DSP filter passband), the bandwidth starts getting narrower, too. This has some of the effects of "Filter Shifting," whether intended or not. Ideally you'd have variable-passband filters usable in all modes, along with several controls, e.g. SHIFT, WIDTH, HI CUT, and LO CUT. It would then be possible to optimize the passband intuitively, as required to deal with QRM (that's the point). And like I mentioned, you'd like to have the benefit of not just shifted filters, but filters that get narrower as required. How does all this apply to the K2? Obviously there isn't room for a suite of passband controls. But you might be able to emulate this functionality using a computer, given the proper remote control commands. (Sounds like something else for the wish-list.) You could also modify the K2's variable-passband CW filter to optimize for wide bandwidths (SSB/DATA) rather than narrow. The same crystals are used both in the main (stock) filter and the KSB2. All you'd need to do is use smaller varactor diodes, preferably a matched set. You might be able to get a 1200-2400 Hz passband range with acceptably low ripple. Food for thought. 73, Wayne N6KR --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@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
RE: [Elecraft] IF Shift vs. Passband Tuning?
Jeff, As far as I know, IF shift and Passbasnd Tuning are the same thing - just different names for the advertizing hype folks to enjoy. The major benefit of Passband tuning is that an interfering signal can be moved off the edge of that reciever passband without changing the pitch of the received signal. IMHO, the same thing can be accomplished by reducing the receiver bandwidth - it matters not whether it is CW or SSB. If the offending signal is on the low side of the wanted signal, it will be necessary to reduce the low frequency content on the wanted signal - OTOH with a voice signal, there will be a lot of information (intelligibility) lost if the passband does not contain energy in the 300 to 500 Hz range, so cutting the low frequency offending signal will result in a loss of intelligibility for the wanted signal. Cutting the high frequency end is quite feasible, and can be accomplished easily by using the variable bandwidth filter provided in the base K2. I can set the normal IF filters to a bandwidth of 1600 Hz and still maintain intelligibility for the male voice (the female voice begins to loose intelligibility at a bandwidth of 1800 Hz or less). Set the low frequency corner of the passband at 300 Hz and accept whatever the high froequency end may be - this is not passband tuning, but is reduction of the high frequency end of the received signal, and I find it as useful (if not more useful) than true passband tuning. I normall set the SSB IF filters to OP1 for the FL1 position, then 300 Hz less for the FL2 position - note that the numbers displayed on the K2 may not be a good indication of the actual bandwidth for wide filter settings, use Spectrogram to determine the actual filter width. With a 2300 (or 2400 Hz) OP1 bandwidth, I set Spectrogram markers at 300 and 2600 Hz then center the passband between those markers. Then FL2 thru FL4 are set to progressively more narrow bandwidths - FL2 = 2200 Hz, FL3 = 1900 Hz, FL4 = 1600 Hz. The important thing is to keep he low frequency corner of the bandpass at 300 Hz to maintain good intelligiblilty. Be aware that the filter bandwidths indicated by the K2 may be substantially different than what is indicated by the K2 display - use Spectrogram to determine the actual filter bandwidth - If the K2 indicates 2200 kHz for the filter bandwidth, it may acually be 2600 Hz wide and quite ragged in the passband - sett it for the actual width as observed o the Spectrogram display. OK, all the above is valid for SSB - for CW, I find it sufficient to simply switch to a more narrow IF filter - if you center the passband at your chosen sidetine pitch, bothe the low and high requencies will be reduced by switching to a more narrow filter. 73, Don W3FPR > -Original Message- > Are IF shift and passband tuning (PBT) the same thing? I assume > that they produce the same effect. I have a Ten-Tec Argonaut V > that has PBT, but I have never used that feature, thus I don't > miss it on my K2. I guess I just don't grasp what PBT would do > for me that I can't do with RIT and the variable width DSP filter > of the Argonaut V. However, I'm a CW op; someone commented that > IF shift is more useful on SSB than on CW. Why is that? > > Thanks, 73 & 72, > Jeff > WB5GWB > Long Island, NY > ___ Elecraft mailing list Post to: Elecraft@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
Re: [Elecraft] I.F. shift thoughts
Now you've done it... On Tue, 8 Aug 2006 7:47 pm, wayne burdick wrote: I think I need an understudy :) ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] IF Shift vs. Passband Tuning?
Hi gang, Are IF shift and passband tuning (PBT) the same thing? I assume that they produce the same effect. I have a Ten-Tec Argonaut V that has PBT, but I have never used that feature, thus I don't miss it on my K2. I guess I just don't grasp what PBT would do for me that I can't do with RIT and the variable width DSP filter of the Argonaut V. However, I'm a CW op; someone commented that IF shift is more useful on SSB than on CW. Why is that? Thanks, 73 & 72, Jeff WB5GWB Long Island, NY ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] I.F. shift thoughts
You can obtain a "quantized" version of I.F. shift with the K2, as someone else mentioned: just assign up to 4 different BFO frequencies when you set up the SSB filters (and use the same bandwidth for each). Hitting XFIL would then rotate through your pre-set shifts. The VFO will read correctly in all cases because CAL FIL offsets the VCO frequency to match each selected BFO setting. However, this is not a continuous control. We could add a menu entry, assignable to PF1 or PF2, that would let you use the VFO knob to get continuous I.F. shift. This is actually on the wish list already, but it requires a number of fairly complex changes to the firmware. It also is one of many functions that we didn't implement because we were out of code space. There are newer chips available that do have enough space, so all I have to do is finish everything else I'm working on. Maybe next year. I think I need an understudy :) 73, Wayne N6KR --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@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
Re: [Elecraft] Why no IF shift ?
Jim, Have just been able to get to read your e-mail. Will answer in full later today - 02:50 am at the moment - probably direct to avoid using Discussion List bandwidth. 73, Geoff GM4ESD - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] ; elecraft@mailman.qth.net Sent: Wednesday, August 09, 2006 12:27 AM Subject: Re: [Elecraft] Why no IF shift ? In a message dated 8/8/06 6:41:46 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: One problem with single down conversion receivers is that their "stronger" spurious responses which, depending on the IF used, can be close to or even in one or more of the frequency bands covered by the receiver. How? ___ Elecraft mailing list Post to: Elecraft@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
RE: [Elecraft] Why no IF shift ?
Hi Group, PRESS your delete button now if you don't like long winded arguement. For the price paid for K2, we have the chance to enjoy exceptionally RX performance near the top end transceivers. Naturally, we have to give up something e.g. band scope specturm, manual notch within AGC loop, IF shift, band pass tuning, FM mode and general TX/RX coverage etc Part of the price paid for K2 is for customer services and support. Elecraft has to be profitable in their business in order to survive. Bearing in mind, quite a portion of the ham population is fond of multiband multifunction all mode rigs. It is nothing wrong for them but competition in the ham rig market is keen. If we are NOT prepared to give up something for such a high performance K2, the price for K2 could be much higher and not affordable by most of the hams. Just taking IC7800 as an example, only 25% of the sale goes to the ham market whereas 75% goes to the institutional users. ICOM earn most of their profit from corporate users. Therefore, you can imagine how many hams can afford high end rigs at high price. For what we got from the K2 is quite a good balance among performance, functions and pricing. Clearly, if there were a new K3 with all the missing functions mentioned in para. 1 above and at similar price tag, I would be delighted to jump into it. However, we have to be realisitc and Eleraft has to make his profit to survive. I share the 'miss' of IF shift and did ask similar question about 4 years ago when I first built my s/n1146. Eventually, I accepted it as a compromise. I have the luck to own / play around most of the top end rigs but I still love my K2. 73 Johnny Siu VR2XMC From: "Don Wilhelm" <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] To: <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>, Subject: RE: [Elecraft] Why no IF shift ? Date: Tue, 8 Aug 2006 20:39:34 -0400 Folks, (long philosophical response - delete if not interested in my opinion). Some very good points mentioned in this thread, but the reality of all of it is compromise. For any given price target, some tradeoffs must be made. If I can interpret the K2 design goals loosely, the dynamic range was considered uppermost, and good sensitivity and IP3 performance running a close second. To achieve that in a kit product, single conversion IMHO is the only realistic way to go. Yes, there ae very good designs out there for multi-conversion receivers and they have their costs and limitations, but the K2 is a compromise of all that. It is single conversion because that is the way to contain the dynamic range and good IP3 characteristics within the chosen price range. It is well known that one must get into the $3K+++ transceivers to achieve those receive parameters that K2/100 owners have achieved for less than half that price. Certainly, IF shift is not an easy acomplishment with a single conversion transceiver. Answering one question posed in the thread which asked why a BFO frequency knob would not do the deed - the answer is YES, BUT - if only the BFO frequency is changed, the displayed frequency would no longer be correct - the firmware currently corrects for both the BFO and VFO frequencies and displays the correct carrier frequency, so while passband tuning might be accomplished simply by changing the BFO, the VFO would have to be altered manually to compensate for the BFO shift, and the resulting frequency on the dial would be incorrect. We used to do exactly that on receivers with a variable BFO, but then we did not have digital dials that were good to the nearest 10 Hz (but I digress). When CAL FIL is run, all that is taken into consideration in the firmware, and the EEPROM values contain the result of that calibration run which produces correct carrier frequency dial readings - you have to give up one thing to gain another in any design process unless 'price is no object'. If the world were perfect, we would all have receivers with a 120+ dB dynamic range, straight sided selectivity curves (with perfectly flat pass band shapes and no change in group delay across the passband), MDS figures in the -160 dB range and all that at a cost of less than $100 - of course I am dreaming based on today's technology and price/performance criteria that would be within the budget of the majority of hams. There is no sense in developing a superior design for production that would sell only one unit because of the cost involved - that is the stuff that extreme designs can produce, but those are currently the stuff of advanced homebrewers - they are the designs of tomorrow when the price of such designs comes down to an affordable level suitable for production. 73, Don W3FPR ___ Elecraft mailing list Post to: Elecraft@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
Re: [Elecraft] Why no IF shift ?
Wow. Thanks Don!! john-n4dsp - Original Message - From: "Don Wilhelm" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; Sent: Tuesday, August 08, 2006 8:39 PM Subject: RE: [Elecraft] Why no IF shift ? Folks, (long philosophical response - delete if not interested in my opinion). Some very good points mentioned in this thread, but the reality of all of it is compromise. For any given price target, some tradeoffs must be made. If I can interpret the K2 design goals loosely, the dynamic range was considered uppermost, and good sensitivity and IP3 performance running a close second. To achieve that in a kit product, single conversion IMHO is the only realistic way to go. Yes, there ae very good designs out there for multi-conversion receivers and they have their costs and limitations, but the K2 is a compromise of all that. It is single conversion because that is the way to contain the dynamic range and good IP3 characteristics within the chosen price range. It is well known that one must get into the $3K+++ transceivers to achieve those receive parameters that K2/100 owners have achieved for less than half that price. Certainly, IF shift is not an easy acomplishment with a single conversion transceiver. Answering one question posed in the thread which asked why a BFO frequency knob would not do the deed - the answer is YES, BUT - if only the BFO frequency is changed, the displayed frequency would no longer be correct - the firmware currently corrects for both the BFO and VFO frequencies and displays the correct carrier frequency, so while passband tuning might be accomplished simply by changing the BFO, the VFO would have to be altered manually to compensate for the BFO shift, and the resulting frequency on the dial would be incorrect. We used to do exactly that on receivers with a variable BFO, but then we did not have digital dials that were good to the nearest 10 Hz (but I digress). When CAL FIL is run, all that is taken into consideration in the firmware, and the EEPROM values contain the result of that calibration run which produces correct carrier frequency dial readings - you have to give up one thing to gain another in any design process unless 'price is no object'. If the world were perfect, we would all have receivers with a 120+ dB dynamic range, straight sided selectivity curves (with perfectly flat pass band shapes and no change in group delay across the passband), MDS figures in the -160 dB range and all that at a cost of less than $100 - of course I am dreaming based on today's technology and price/performance criteria that would be within the budget of the majority of hams. There is no sense in developing a superior design for production that would sell only one unit because of the cost involved - that is the stuff that extreme designs can produce, but those are currently the stuff of advanced homebrewers - they are the designs of tomorrow when the price of such designs comes down to an affordable level suitable for production. 73, Don W3FPR -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Tuesday, August 08, 2006 7:27 PM To: [EMAIL PROTECTED]; elecraft@mailman.qth.net Subject: Re: [Elecraft] Why no IF shift ? In a message dated 8/8/06 6:41:46 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > One problem with single down conversion receivers is that their > "stronger" spurious responses which, depending on the IF used, can be close > to or even in one or more of the frequency bands covered by the receiver. How? In a single conversion superhet, the most important spurs are the image and IF feedthrough. In the case of a K2, the image is always about 9.830 MHz from the desired signal, and the IF is around 4.915 MHz. The bandpass filters take care of those spurs very well, in my experience. If > > bandpass filters are used between the antenna connector and the mixer, their > > selectivity might offer some degree of protection against signals coming in > at spurious response frequencies outside but close to the bands covered but > obviously no protection against anything coming in at an "in-band" spurious > response frequency. What in band spurs exist in the K2? The choice of IF that reduces this problem in a single > > down conversion receiver is quite limited. > > In a double conversion receiver, up and then down, assuming that sensible > design and construction practices are followed, the close or in-band > spurious responses (if they exist) are considerably reduced. > That may be the case in a general-coverage receiver, but in a ham-bands-only design, the spurious responses are easily handled by good input filters. > Then there is the internal birdie problem, usually created by one or more > of > the receiver's oscillators and /or their harmonics getting together to > produce a signal at some spurious response frequency of the receiver. Again, this
RE: [Elecraft] Why no IF shift ?
Folks, (long philosophical response - delete if not interested in my opinion). Some very good points mentioned in this thread, but the reality of all of it is compromise. For any given price target, some tradeoffs must be made. If I can interpret the K2 design goals loosely, the dynamic range was considered uppermost, and good sensitivity and IP3 performance running a close second. To achieve that in a kit product, single conversion IMHO is the only realistic way to go. Yes, there ae very good designs out there for multi-conversion receivers and they have their costs and limitations, but the K2 is a compromise of all that. It is single conversion because that is the way to contain the dynamic range and good IP3 characteristics within the chosen price range. It is well known that one must get into the $3K+++ transceivers to achieve those receive parameters that K2/100 owners have achieved for less than half that price. Certainly, IF shift is not an easy acomplishment with a single conversion transceiver. Answering one question posed in the thread which asked why a BFO frequency knob would not do the deed - the answer is YES, BUT - if only the BFO frequency is changed, the displayed frequency would no longer be correct - the firmware currently corrects for both the BFO and VFO frequencies and displays the correct carrier frequency, so while passband tuning might be accomplished simply by changing the BFO, the VFO would have to be altered manually to compensate for the BFO shift, and the resulting frequency on the dial would be incorrect. We used to do exactly that on receivers with a variable BFO, but then we did not have digital dials that were good to the nearest 10 Hz (but I digress). When CAL FIL is run, all that is taken into consideration in the firmware, and the EEPROM values contain the result of that calibration run which produces correct carrier frequency dial readings - you have to give up one thing to gain another in any design process unless 'price is no object'. If the world were perfect, we would all have receivers with a 120+ dB dynamic range, straight sided selectivity curves (with perfectly flat pass band shapes and no change in group delay across the passband), MDS figures in the -160 dB range and all that at a cost of less than $100 - of course I am dreaming based on today's technology and price/performance criteria that would be within the budget of the majority of hams. There is no sense in developing a superior design for production that would sell only one unit because of the cost involved - that is the stuff that extreme designs can produce, but those are currently the stuff of advanced homebrewers - they are the designs of tomorrow when the price of such designs comes down to an affordable level suitable for production. 73, Don W3FPR > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] > Sent: Tuesday, August 08, 2006 7:27 PM > To: [EMAIL PROTECTED]; elecraft@mailman.qth.net > Subject: Re: [Elecraft] Why no IF shift ? > > > In a message dated 8/8/06 6:41:46 AM Eastern Daylight Time, > [EMAIL PROTECTED] writes: > > > > One problem with single down conversion receivers is that their > > "stronger" spurious responses which, depending on the IF used, > can be close > > to or even in one or more of the frequency bands covered by the > receiver. > > How? > > In a single conversion superhet, the most important spurs are the > image and > IF feedthrough. In the case of a K2, the image is always about > 9.830 MHz from > the desired signal, and the IF is around 4.915 MHz. The bandpass > filters take > care of those spurs very well, in my experience. > > If > > > > bandpass filters are used between the antenna connector and the > mixer, their > > > > selectivity might offer some degree of protection against > signals coming in > > at spurious response frequencies outside but close to the bands > covered but > > obviously no protection against anything coming in at an > "in-band" spurious > > response frequency. > > What in band spurs exist in the K2? > > The choice of IF that reduces this problem in a single > > > > down conversion receiver is quite limited. > > > > In a double conversion receiver, up and then down, assuming > that sensible > > design and construction practices are followed, the close or in-band > > spurious responses (if they exist) are considerably reduced. > > > > That may be the case in a general-coverage receiver, but in a > ham-bands-only > design, the spurious responses are easily handled by good input filters. > > > Then there is the internal birdie problem, usually created by > one or more > > of > > the receiver's oscillators and /or their harmonics getting together to > > produce a signal at some spurious response frequency of the receiver. > > Again, this is dependent on the design. For a ham-bands-only > receiver, the > birdies can be placed outside the ham bands. > > If the > > > > Front E
Re: [Elecraft] Why no IF shift ?
In a message dated 8/8/06 6:41:46 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > One problem with single down conversion receivers is that their > "stronger" spurious responses which, depending on the IF used, can be close > to or even in one or more of the frequency bands covered by the receiver. How? In a single conversion superhet, the most important spurs are the image and IF feedthrough. In the case of a K2, the image is always about 9.830 MHz from the desired signal, and the IF is around 4.915 MHz. The bandpass filters take care of those spurs very well, in my experience. If > > bandpass filters are used between the antenna connector and the mixer, their > > selectivity might offer some degree of protection against signals coming in > at spurious response frequencies outside but close to the bands covered but > obviously no protection against anything coming in at an "in-band" spurious > response frequency. What in band spurs exist in the K2? The choice of IF that reduces this problem in a single > > down conversion receiver is quite limited. > > In a double conversion receiver, up and then down, assuming that sensible > design and construction practices are followed, the close or in-band > spurious responses (if they exist) are considerably reduced. > That may be the case in a general-coverage receiver, but in a ham-bands-only design, the spurious responses are easily handled by good input filters. > Then there is the internal birdie problem, usually created by one or more > of > the receiver's oscillators and /or their harmonics getting together to > produce a signal at some spurious response frequency of the receiver. Again, this is dependent on the design. For a ham-bands-only receiver, the birdies can be placed outside the ham bands. If the > > Front End, LO and IF are not properly shielded in separate "boxes" with all > associated DC and control lines filtered, then expect birdies in a single > down conversion receiver. The same method of construction should be used in > a double conversion receiver. I suspect that commercial double conversion > amateur receivers have received a bad press because for reasons of cost this > > is usually not done. > There are some very good up/down double conversion amateur receivers. But they all suffer from the same problem: The signal has to go through several stages and conversions before it gets to the sharp filters. In a single conversion design like the K2, the number of stages and conversions between antenna and sharp filter is minimized. > It is true that every conversion degrades the performance, but for several > years the technology has been available that allows a double conversion > receiver to be built which exhibits an IIP3 of +40dbm > at an offset of 2 kHz while running at full gain, Noise Figure of 8db on > 10m. I have one here. The downside is that each one of the three VHF roofing > > filters / embedded amplifiers selected draws 240 mA. > There's also the issue of price > With double conversion, in addition to true "IF Shift" a form of continuous > > bandwidth control can also be introduced. > 73 de Jim, N2EY ___ Elecraft mailing list Post to: Elecraft@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
RE: [Elecraft] K60XV - the drama continues
John, The Info 080 says that the main K2 microprocessor knows that the option is present, but its firmware has not properly responded. Check the soldering at the header pins (both the RF Board and the option board) and check the soldering at the K60XV firmware chip. If that does not correct it, I recommend that you call Scott or Brian at Elecraft and discuss the possibility of a firmware chip replacement. There is one very remote possibility that the header in the RF board has a pin that is not making adequate contact. 73, Don W3FPR > -Original Message- > > The Don responded in usual rapid manner that my K60XV was probably > not plugged in properly...pins off by a space. > > I have now tried many times and here's how it behaves... > > If the pins are off (which I verified) then the band cannot be > found. Display shows all other bands when scrolling thru. > > If the pins are correctly inserted, the evil "INFO 080" is displayed > immediately upon turning the unit on. > > Other than replacing the processor on the board, the manual is > silent...checked the values of R1 and C12 and the notch on U1 is > facing the relay. > > ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] K60XV - the drama continues
The Don responded in usual rapid manner that my K60XV was probably not plugged in properly...pins off by a space. I have now tried many times and here's how it behaves... If the pins are off (which I verified) then the band cannot be found. Display shows all other bands when scrolling thru. If the pins are correctly inserted, the evil "INFO 080" is displayed immediately upon turning the unit on. Other than replacing the processor on the board, the manual is silent...checked the values of R1 and C12 and the notch on U1 is facing the relay. Any ideas? John AB8WH ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] OT: FS: Vibroplex "Code Warrior Junior" paddles
Paddles have been sold, thanks to all that enquired. W0EB ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] Re: Why no IF shift ?
Thanks to the various respondents. I got the point. BTW, my passband question was about SSB, no CW. Though I do some phone contesting, I am obviously not experienced enough, is that why I am grateful to the IF shift of my FT-100D :-) ? Do I correctly understand ( my K2 will arrive next week ) that, if the BFO would be a frontpanel button, a bandpass shift would be born ? ( delta tune + delta BFO = bandpass shift ? ). Could one make such a BFO button oneself or does the firmware forbid such ? Again, thanks to all.. Peter, PE1E - Original Message - From: "PE1E" <[EMAIL PROTECTED]> To: Sent: Tuesday, August 08, 2006 12:50 AM Subject: Why no IF shift ? > Bit by bit I learn K2 is loaded with quality not commonly found in other HF > ham gear. > Why no ( real.. ) IF shift ? ( common in all " other " rigs , even my cheap > FT-100's ). > > Peter, PE1E > ___ Elecraft mailing list Post to: Elecraft@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
Re: [Elecraft] RE: Band Conditions (Ron D'Eau Claire)
Nice post Clark. Agree with you on Ron. One can learn much from his through posts. 73 john-n4dsp - Original Message - From: "Clark Macaulay" <[EMAIL PROTECTED]> To: "ElecraftList" Sent: Tuesday, August 08, 2006 10:21 AM Subject: [Elecraft] RE: Band Conditions (Ron D'Eau Claire) Ron, Just a quick note to tell you how much I appreciate your reasoned and complete answers on virtually every topic you choose. At times, I feel like I'm learning from the master and wish I could package all of your experience and advice on a ROM and plug it into my left temple! Even though I'm an Extra, I still have much to learn, and you (among others on this list) are helping me to become the type of ham I wanna be. 73, Clark, ke4rq ___ Elecraft mailing list Post to: Elecraft@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 -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.405 / Virus Database: 268.10.7/411 - Release Date: 8/7/2006 ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] OT: FS: Vibroplex "Code Warrior Junior" paddles
For sale: Vibroplex "Code Warrior Junior" paddles. Vibroplex's commercial version of the NorCal paddles. Tension is by magnets and there are no springs. Gold plated contacts and they have a unique feel that is easy to get used to. They are also pretty rugged and will take a bit of hard use. Finger pieces are fairly thick, clear plexiglas and I understand that if you don't like clear, you can get red ones from Vibroplex. Schurr or Begali paddles they aren't, but they are decent and work well with the K1 or K2's internal keyer. The base is powder coated steel and heavy enough to keep the paddles in place if you don't bang 'em around. This set was made in September of 2002. The date 09 02 and the serial # 1242 are engraved on the bottom. Vibroplex's price was $94.95. I'll sell this one for $65.00 shipped anywhere in the US. Canada and overseas will need to negotiate postage. I'll take money order or PayPal. Inquiries off list please to keep reflector bandwidth to a minimum, thanks. Jim Sheldon, W0EB K2 #4338 [EMAIL PROTECTED] ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] RE: Band Conditions (Ron D'Eau Claire)
Ron, Just a quick note to tell you how much I appreciate your reasoned and complete answers on virtually every topic you choose. At times, I feel like I'm learning from the master and wish I could package all of your experience and advice on a ROM and plug it into my left temple! Even though I'm an Extra, I still have much to learn, and you (among others on this list) are helping me to become the type of ham I wanna be. 73, Clark, ke4rq ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] K1
Greetings, I'm a new member and this is my first post. I'm about 1/3 of the way through the assembly of the K1 (with backlight) which I'll use on 20 and 40 meters. Over the years, I've put together a few dozen kits and would be grateful to know if there are any little "kinks" with this kit, or things that will improve performance that could be done during assembly. An example would be to replace a transistor and the biasing network attendant to it with other parts to have a quieter audio chain. All hints, tips, words of wisdom, counsel and advice are appreciated. 72, Tim Colbert K3HX Try Juno Platinum for Free! Then, only $9.95/month! Unlimited Internet Access with 1GB of Email Storage. Visit http://www.juno.com/value to sign up today! ___ Elecraft mailing list Post to: Elecraft@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
RE: [Elecraft] s/n 5567 Alignment and Test Part II problems
Terry, You do have a problem. First thing to do is check the soldering carefully, then re-check the soldering. When you have finished that, check the soldering. That is the most common failure. The second most common failure is components finding their way into the wrong holes. To narrow your search in this particular case, open the schematic to the RF Board sheet 1 of 4 and find the components shown in the upper left area - marked 'PLL Reference Oscillator'. You will likely find the source of your problem among those components - include the thermistor board (and the soldering on the back of it) in that list of suspects. Don't be concerned about the 4 MHz reference oscillator right now - just set C22 to the center position as indicated in the manual. After you complete the K2 and have everything working, you can take steps to set the reference accurately. The internal check you did says nothing about the accuracy of the 4 MHz oscillator - it only tells you that the counter is working. 73, Don W3FPR > -Original Message- > > > I have just completed RF assembly part II and started the > alignment and test when right off the bat I have a problem. > > > The "4 MHz Oscillator Calibration" step 3 on page 60 states "the > counter should show a frequency of 12090 kHz +/- 30 kHz". Well > mine reads 12600. Searching the archive I found plenty of > examples of the PLL reference oscillator range test but nothing > about not getting the wrong reading. I checked the freq probe by > testing and finding 4000.00 at C22. > > > Any suggestions on where to start troubleshooting. > > ___ Elecraft mailing list Post to: Elecraft@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
Re: [Elecraft] strong signal on 17 m in K1
(Copy of this also sent to elecraft mailing list) Paul, mine is 0n 18.113.7 loud and clear just like a cleane tone, my guess: 6th overtone from VFO, 18.113.7 / 6 gives 3.018 MHz and my VFO is ranged 3.000-3.090. Possible your VFO range is not the same as mine. I can also hear this on my portable Sangean world receiver. If I multiply 3.018 by 2, 3 and 4 etc also these frequencies is well heard on the sangean RX. Well in that case nothing to do i guess, I just dont need to operate around 18.113 Mc:s... Perhaps the VFO area in the K1 should be inside some sort of shielding, and passing thru a low-pass filter before the premix... 73 have a good day, / Chris tis 2006-08-08 klockan 03:02 -0700 skrev Paul Gates, KD3JF: > Krister, I hear the noise on 18.115.7 and am not sure what it is. > > Paul, KD3JF > Glen Burnie, Maryland > > Krister Eriksson <[EMAIL PROTECTED]> wrote: > Hello! > > I have noticed a very strong carrier in my K1 on 17 meter, I > forgot the > exact frequency, but around 18.113 This carrier is still there > even > with no antenna connected. Is this normal? > > Yesterday I was portable a few hours and the rig is working > fine, but > the condx is not very good now.. > > 73 / SM5KRI/P Chris > > > End of Elecraft Digest, Vol 28, Issue 8 > > *** > -- > Krister Eriksson > Ringduvegatan 23 > 724 70 Västerås, Sweden > > [Hamradio: SM5KRI] > [ [EMAIL PROTECTED] ] > > > ___ Elecraft mailing list Post to: Elecraft@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
Re: [Elecraft] Why no IF shift ?
Ron AC7AC wrote: Others pointed out the reason - single conversion design. That single-conversion design is also what helps the K2's performance excel compared to those with multiple-conversions that allow for an "IF Shift" knob. Frequency conversions in receivers are like making copies in photography. You can go to great extremes to make each copy very high quality, but each generation degrades the image, just the same. In a receiver, every conversion degrades the performance, no matter how hard the engineers try to avoid it. - Hang on . One problem with single down conversion receivers is that their "stronger" spurious responses which, depending on the IF used, can be close to or even in one or more of the frequency bands covered by the receiver. If bandpass filters are used between the antenna connector and the mixer, their selectivity might offer some degree of protection against signals coming in at spurious response frequencies outside but close to the bands covered but obviously no protection against anything coming in at an "in-band" spurious response frequency. The choice of IF that reduces this problem in a single down conversion receiver is quite limited. In a double conversion receiver, up and then down, assuming that sensible design and construction practices are followed, the close or in-band spurious responses (if they exist) are considerably reduced. Then there is the internal birdie problem, usually created by one or more of the receiver's oscillators and /or their harmonics getting together to produce a signal at some spurious response frequency of the receiver. If the Front End, LO and IF are not properly shielded in separate "boxes" with all associated DC and control lines filtered, then expect birdies in a single down conversion receiver. The same method of construction should be used in a double conversion receiver. I suspect that commercial double conversion amateur receivers have received a bad press because for reasons of cost this is usually not done. It is true that every conversion degrades the performance, but for several years the technology has been available that allows a double conversion receiver to be built which exhibits an IIP3 of +40dbm at an offset of 2 kHz while running at full gain, Noise Figure of 8db on 10m. I have one here. The downside is that each one of the three VHF roofing filters / embedded amplifiers selected draws 240 mA. With double conversion, in addition to true "IF Shift" a form of continuous bandwidth control can also be introduced. 73, Geoff GM4ESD ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] Re: Why no IF shift?
Jim N2EY wrote :- >Most "other" rigs implement IF shift by an extra conversion step after the first fixed IF. This means there's a lot of gain and stages between the antenna and the sharp selectivity "knothole". No thanks. IMHO, IF shift is of limited use in a CW receiver ...> More so in a contest situation. Our CW contest club (ZM1A) presently uses an ICOM 781 and a K2 in a Multi-One or Multi-Two category in many contests. These are rigs of choice because of problems with other rigs in the shack - phase noise etc. As the host I get to pass the sandwiches, pizza wedges and pour the drinks, so I have the opportunity to closely observe class operators like Jacky F3CW (ZL3CW) and Aki ZL1GO (JA4EKO) in action when they are running at 200+ per hour. They seldom touch the transceivers - very occasionally adjust the RIT and very seldom reduce the filter width, only because there is some adjacent and temporary QRM. The 781 has IF Shift - unused. Our K2s have KAF2 filters (sometimes used) . These ops have filters in their ears. 73, Ken ZL1AIH ___ Elecraft mailing list Post to: Elecraft@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
[Elecraft] strong signal on 17 m in K1
Hello! I have noticed a very strong carrier in my K1 on 17 meter, I forgot the exact frequency, but around 18.113 This carrier is still there even with no antenna connected. Is this normal? Yesterday I was portable a few hours and the rig is working fine, but the condx is not very good now.. 73 / SM5KRI/P Chris > End of Elecraft Digest, Vol 28, Issue 8 > *** -- Krister Eriksson Ringduvegatan 23 724 70 Västerås, Sweden [Hamradio: SM5KRI] [ [EMAIL PROTECTED] ] ___ Elecraft mailing list Post to: Elecraft@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
