Re: [Elecraft] RSGB RadCom K3 review posted on RSGB Members web page
Overall I am very pleased with the review that Peter produced. Having chided him somewhat over the lack of a K2 review, I and others pushed him quite hard towards producing one for the K3. Given that the K3 is quite a different beast to the Far East Black Boxes he normally reviews, the end result IMHO is quite good. I don't know where, given the continual changes in the K3 development/manufacturing timeline would be a better place to conduct a review. I don't think the RadCom (RSGB) has had any interest either way in the K3 review, other than to provide an interesting read for the membership. As has been said before the RSGB does not purchase radios anonymously, the reviewer is normally loaned them by a dealer. The K3 review is very different in that this time the unit came from a user. Probably this approach is better at showing the rig, warts and all. 73 Stewart G3RXQ On Thu, 19 Jun 2008 05:49:29 -0700, David Yarnes wrote: > Ian and All, > > While I agree with much of what you say, and I sympathize with the various > issues, I can't quite agree that it necessarily is a "good reason" for > everything. > > First of all, U.K. stations had the same access to K3's as U.S. stations > did. Indeed, many U.K. bound units were included in the early shipments. > But Elecraft's production delays does make it extremely complex to get a > unit on any kind of a predictable timeline. If Radcom intended to review > the K3 (and I would assume they should have been interested from day 1), > they should have probably been quicker off the mark to get a unit in the > "Que", unless they were willing to delay review until they had proper time > to do it right. I'm not saying Peter did it wrong--indeed his review may be > quite accurate based on the radio he had--but saying he didn't have enough > time suggests a hurried review. > > It seems to me that any committment to make such a review should be > predicated on having sufficient time to do it properly. If Radcom wants it > done earlier, they should insure access to a unit on a timely basis. The > timing should not be the sole responsibility of the author. > > I also don't understand why any review (QST, Radcom, or otherwise) would be > done without allowing sufficient time for communication with the > manufacturer in case problems arise. Now, if the manufacturer doesn't > cooperate, so be it. But I assume Elecraft, or any manufacturer, would want > to be consulted about any claimed specifications not achieved. The need to > work with the manufuacturer should be disclosed, as it says something about > the status of "production units", but the long term benefit of the review > really depends on disclosing whether or not claimed specifications are > achievable, and what it took to get there. After all, the problem could > possibly be on either end. > > In short, I think any review that is "rushed" due to time constraints is of > limited value. I'm not being naive' about deadlines, but deadlines must be > imposed reasonably. I also think that a review should be something that is > updatable. If issues occur, which are subsequently resolved, I think it's > good practice to disclose them on a timely basis in a subsequent issue, > including how it was achieved. Buyers rely heavily on such reviews, and I > would think it is in everyone's interest to do them as completely as > possible. And they shouldn't "pull any punches" either. I hate it when > reviewers seem to "gloss" around certain issues. If it doesn't perform as > advertised, say so!!! > > Dave W7AQK > > - Original Message - > From: "Ian White GM3SEK" <[EMAIL PROTECTED]> > To: > Sent: Thursday, June 19, 2008 12:21 AM > Subject: Re: [Elecraft] RSGB RadCom K3 review posted on RSGB Members web > page > > >> Like the ARRL review, this one was very much a first shot - and as we all >> well know, the K3 is a moving target. >> >> A few words about Radcom reviews may help put this into perspective. >> Availability of new models is typically several months behind the USA, and >> quite frequently the QST review is already in print before a reviewer in >> Europe can even lay hands on the hardware. This puts reviewers under >> intense time pressure. >> >> On receiving the equipment, the reviewer has a very short time to make >> some basic functional checks, just to confirm that the equipment is fit to >> be reviewed. More than once, I have rejected equipment at this point, and >> I'm sure Peter Hart has too. But once a reviewer commits himself to the >> magazine's production schedule, the process cannot
Re: [Elecraft] RSGB RadCom K3 review posted on RSGB Members web page
Ian and All, While I agree with much of what you say, and I sympathize with the various issues, I can't quite agree that it necessarily is a "good reason" for everything. First of all, U.K. stations had the same access to K3's as U.S. stations did. Indeed, many U.K. bound units were included in the early shipments. But Elecraft's production delays does make it extremely complex to get a unit on any kind of a predictable timeline. If Radcom intended to review the K3 (and I would assume they should have been interested from day 1), they should have probably been quicker off the mark to get a unit in the "Que", unless they were willing to delay review until they had proper time to do it right. I'm not saying Peter did it wrong--indeed his review may be quite accurate based on the radio he had--but saying he didn't have enough time suggests a hurried review. It seems to me that any committment to make such a review should be predicated on having sufficient time to do it properly. If Radcom wants it done earlier, they should insure access to a unit on a timely basis. The timing should not be the sole responsibility of the author. I also don't understand why any review (QST, Radcom, or otherwise) would be done without allowing sufficient time for communication with the manufacturer in case problems arise. Now, if the manufacturer doesn't cooperate, so be it. But I assume Elecraft, or any manufacturer, would want to be consulted about any claimed specifications not achieved. The need to work with the manufuacturer should be disclosed, as it says something about the status of "production units", but the long term benefit of the review really depends on disclosing whether or not claimed specifications are achievable, and what it took to get there. After all, the problem could possibly be on either end. In short, I think any review that is "rushed" due to time constraints is of limited value. I'm not being naive' about deadlines, but deadlines must be imposed reasonably. I also think that a review should be something that is updatable. If issues occur, which are subsequently resolved, I think it's good practice to disclose them on a timely basis in a subsequent issue, including how it was achieved. Buyers rely heavily on such reviews, and I would think it is in everyone's interest to do them as completely as possible. And they shouldn't "pull any punches" either. I hate it when reviewers seem to "gloss" around certain issues. If it doesn't perform as advertised, say so!!! Dave W7AQK - Original Message - From: "Ian White GM3SEK" <[EMAIL PROTECTED]> To: Sent: Thursday, June 19, 2008 12:21 AM Subject: Re: [Elecraft] RSGB RadCom K3 review posted on RSGB Members web page Like the ARRL review, this one was very much a first shot - and as we all well know, the K3 is a moving target. A few words about Radcom reviews may help put this into perspective. Availability of new models is typically several months behind the USA, and quite frequently the QST review is already in print before a reviewer in Europe can even lay hands on the hardware. This puts reviewers under intense time pressure. On receiving the equipment, the reviewer has a very short time to make some basic functional checks, just to confirm that the equipment is fit to be reviewed. More than once, I have rejected equipment at this point, and I'm sure Peter Hart has too. But once a reviewer commits himself to the magazine's production schedule, the process cannot be stopped. If subtle issues emerge from the detailed measurements, the reviewer will report whatever he sees. 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek ___ 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 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] RSGB RadCom K3 review posted on RSGB Members web page
Stewart I agree with you. I haven't completely read the RSGB K3 review yet. But I think I will trust the ARRL results, Bob Sherwood's and those of Elecraft more than those of the 'RSGB'. 73 Rob G3RCE - Stewart G3RXQ said: More the need for advertising revenue, I suspect... - ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
Eric Swartz - WA6HHQ, Elecraft wrote: Looks like he clearly had a bad 500 Hz filter. It does not match our measurements here or Sherwood's. We'll make sure the customer gets a replacement. We were not contacted prior to publication so we were unable to replace it ahead of time. Like the ARRL review, this one was very much a first shot - and as we all well know, the K3 is a moving target. A few words about Radcom reviews may help put this into perspective. Availability of new models is typically several months behind the USA, and quite frequently the QST review is already in print before a reviewer in Europe can even lay hands on the hardware. This puts reviewers under intense time pressure. On receiving the equipment, the reviewer has a very short time to make some basic functional checks, just to confirm that the equipment is fit to be reviewed. More than once, I have rejected equipment at this point, and I'm sure Peter Hart has too. But once a reviewer commits himself to the magazine's production schedule, the process cannot be stopped. If subtle issues emerge from the detailed measurements, the reviewer will report whatever he sees. The issue about the 500Hz filter was one of that kind, and I don't believe it was dealt with unfairly. All parties agree that it would be extremely hard to spot by a normal user. The problem does need to be investigated - was it confined to that individual filter, or could it affect any or all of them... or is there a measurement problem? - but all that needs to be done on a much longer and more (ahem) measured timescale. The reason Elecraft didn't make the front cover seems perfectly simple - no dark conspiracy but simply that Alinco provided superb photo artwork that no editor could possibly resist. Sorry, folks, but editors of radio magazines see far too many pictures of black boxes with glowing displays... Also, their TX tests were incorrectly run at 120W instead of at our spec limit of 100w. TX IMD will degrade at least 5 dB at 120W. That's there for the CW guys ;-) Equally important would be that Peter's editorial deadline (which is the same as mine) would have been before the major firmware update that considerably improved the SSB performance. It's pretty certain that he didn't try any upgrades himself, or else he'd surely have mentioned how simple it is. All of these issues could perhaps be addressed in a "10,000 mile report" sometime down the road. (I'll be away now until Tuesday. Mike - listen out for me in Abingdon... you won't need a radio :-) -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
On Wed, 18 Jun 2008 11:14:07 -0700 (PDT), AD6XY - Mike wrote: > > I have Radcom in front of me. The editor has two reviews, the K3 and a new > Alinco hand held. I suppose it shows the state of amateur radio in the UK > that the hand held makes the front cover. More the need for advertising revenue, I suspect... 73 Stewart G3RXQ ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
Bill W4ZV wrote: > > > > AD6XY - Mike wrote: >> >> >> So... to your figures. The 500Hz filter is 8 dB worse than the 2.7 kHz >> filter out of band but at close spacings. According to the review it >> suffers non-linearites not noted in the 2.7kHz stock filter nor the 8 >> pole INRAD the 400Hz filter. >> > > NOT SO...G3SJX only tested the 2.7k, 1.8k and a 500...NOT a 400. He was > speculating about the 400 because Sherwood and ARRL had good measurements > with one (Sherwood had nearly identical IMD measurements with the 500 > which I posted previously - below). > The wonders of English. It depends how you read "according to the review". In any case we now know it was a flawed filter or (if you are right about the 1.8k) perhaps a problem in the IF of that particular K3. The faulty 500Hz filter at 40kHz spacing has a 3rd order intercept of +27 dBm Just what we need over here in Europe to counter the broadcast signals just above 7.1 MHz. I take Eric's point about the power measurements but I speculate most operators (but obviously excluding all elecraft owners and QRPers who would never dream of doing such a thing) tune their transmitters for maximum power in attempting to crack a pile-up or for a contest. It is a fair assessment of what it could sound like on air, in the worst hands and it is still very good. Mike -- View this message in context: http://www.nabble.com/RSGB-RadCom-K3-review-posted-on-RSGB-Members-web-page-tp17988333p17990867.html Sent from the Elecraft mailing list archive at Nabble.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] RSGB RadCom K3 review posted on RSGB Members web page
The spec difference is almost impossible to detect in normal usage. It takes very clean lab signal generators to test. We're talking about extreme signals that might just start to cause barely noticeable IMD in the 'bad' filter. Even the 'bad' filter IMD is better than most other rigs on the market. It just looks like a one off failure. (This can happen in any xtal filter from any mfg.) 73, Eric Jerry Flanders wrote: At 02:44 PM 6/18/2008, Eric Swartz - WA6HHQ, Elecraft wrote: Looks like he clearly had a bad 500 Hz filter. It does not match our measurements here or Sherwood's. We'll make sure the customer gets a replacement. Just curious - do you guys check filters before shipping them? Most of us out here wouldn't have a clue if we had a bad filter - we would just suffer with poor performance without ever knowing why. Jerry W4UK ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
Let's stop speculating. Did anybody talk to the guy? 73, Arie PA3A ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
AD6XY - Mike wrote: > > I have Radcom in front of me. The editor has two reviews, the K3 and a new > Alinco hand held. I suppose it shows the state of amateur radio in the UK > that the hand held makes the front cover. The K3 reviews very well > indeed. > > So... to your figures. The 500Hz filter is 8 dB worse than the 2.7 kHz > filter out of band but at close spacings. According to the review it > suffers non-linearites not noted in the 2.7kHz stock filter nor the 8 pole > INRAD the 400Hz filter. > NOT SO...G3SJX only tested the 2.7k, 1.8k and a 500...NOT a 400. He was speculating about the 400 because Sherwood and ARRL had good measurements with one (Sherwood had nearly identical IMD measurements with the 500 which I posted previously - below). There's another problem with the 1.8k data which also looks bad. Sorry but I trust Elecraft/Sherwood's published measurements of the 400/500 listed below. Peter may have had both a bad 1.8k and 500. http://mailman.qth.net/pipermail/elecraft/2008-June/091593.html http://mailman.qth.net/pipermail/elecraft/2008-June/091606.html 73, Bill -- View this message in context: http://www.nabble.com/RSGB-RadCom-K3-review-posted-on-RSGB-Members-web-page-tp17988333p17990221.html Sent from the Elecraft mailing list archive at Nabble.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] RSGB RadCom K3 review posted on RSGB Members web page
At 02:44 PM 6/18/2008, Eric Swartz - WA6HHQ, Elecraft wrote: Looks like he clearly had a bad 500 Hz filter. It does not match our measurements here or Sherwood's. We'll make sure the customer gets a replacement. Just curious - do you guys check filters before shipping them? Most of us out here wouldn't have a clue if we had a bad filter - we would just suffer with poor performance without ever knowing why. Jerry W4UK ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
Looks like he clearly had a bad 500 Hz filter. It does not match our measurements here or Sherwood's. We'll make sure the customer gets a replacement. We were not contacted prior to publication so we were unable to replace it ahead of time. Also, their TX tests were incorrectly run at 120W instead of at our spec limit of 100w. TX IMD will degrade at least 5 dB at 120W. That's there for the CW guys ;-) 73, Eric WA6HHQ AD6XY - Mike wrote: So... to your figures. The 500Hz filter is 8 dB worse than the 2.7 kHz filter out of band but at close spacings. According to the review it suffers non-linearites not noted in the 2.7kHz stock filter nor the 8 pole INRAD the 400Hz filter. These showed odd properties with tone spacing that makes me think it was the DSP responding to the wider skirts of the 5 pole 500Hz filter but maybe that particular filter had a fault, it happens with crystals. Even so 88 dB dynamic range at 2kHz is not at all bad. I am sure the experts can explain this behaviour but for now I think it might be better to order an 8 pole 400Hz filter than a 5 pole 500Hz one - you will be able to sleep better. Mike ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
I have Radcom in front of me. The editor has two reviews, the K3 and a new Alinco hand held. I suppose it shows the state of amateur radio in the UK that the hand held makes the front cover. The K3 reviews very well indeed. So... to your figures. The 500Hz filter is 8 dB worse than the 2.7 kHz filter out of band but at close spacings. According to the review it suffers non-linearites not noted in the 2.7kHz stock filter nor the 8 pole INRAD the 400Hz filter. These showed odd properties with tone spacing that makes me think it was the DSP responding to the wider skirts of the 5 pole 500Hz filter but maybe that particular filter had a fault, it happens with crystals. Even so 88 dB dynamic range at 2kHz is not at all bad. I am sure the experts can explain this behaviour but for now I think it might be better to order an 8 pole 400Hz filter than a 5 pole 500Hz one - you will be able to sleep better. Mike Douglas G. Bonett wrote: > > The numbers reported below are close to what I would expect if the 2.7 kHz > and > 500 Hz column labels were accidentally switched. Typo maybe? > > Doug N0HH > > > = > Yes something isn´t right. This was his measurements: > > CLOSE-IN INTERMODULATION ON 7MHz band,500Hz bandwidth, CW preamp off > > 2.7 kHz roofing 1.8 kHz roofing 500 Hz roofing > 2kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB > 3kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB > 5kHz +22dBm 103dB+12.5dBm 96dB+8.5dBm 92dB > 7kHz +22dBm 103dB+12.5dBm 96dB+13dBm95dB > 10kHz +22dBm 103dB+12.5dBm 96dB+17.5dBm 98dB > 15kHz +22dBm 103dB+12.5dBm 96dB+22dBm 101dB > 20kHz +22dBm 103dB+12.5dBm 96dB+25dBm 103dB > 30kHz +22dBm 103dB+12.5dBm 96dB+26.5dBm 104dB > 40kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB > 50kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB > > > > ___ > 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 > > -- View this message in context: http://www.nabble.com/RSGB-RadCom-K3-review-posted-on-RSGB-Members-web-page-tp17988333p17988830.html Sent from the Elecraft mailing list archive at Nabble.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] RSGB RadCom K3 review posted on RSGB Members web page
I don't understand why the IMD figures worsen as the roofing filter narrows. Also I've always been led to understand that the signal spacing likely to cause IMD problems is roughly 0.25 of the roofing filter bandwidth assuming a narrow final passband. On this basis, and even allowing for responses down to the -60dB level (say 5kHz for the 2.7K filter...) none of the quoted signal spacings should be 'getting through' any of the roofing filters listed. So at these spacings the IMD response should be a function only of the pre first mixer circuitry which doesn't explain (to me!) the significant variations with roofing filter. I'm sure I'm missing something here, perhaps about how these things are actually measured; anyone care to put me right? Stewart Rolfe, GW0ETF (K3/100 #145) Bill W4ZV wrote: > > > > Jan Erik Holm wrote: >> >> Yes something isn´t right. This was his measurements: >> >> CLOSE-IN INTERMODULATION ON 7MHz band,500Hz bandwidth, CW preamp off >> >> 2.7 kHz roofing 1.8 kHz roofing 500 Hz roofing >> 2kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB >> 3kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB >> 5kHz +22dBm 103dB+12.5dBm 96dB+8.5dBm 92dB >> 7kHz +22dBm 103dB+12.5dBm 96dB+13dBm95dB >> 10kHz +22dBm 103dB+12.5dBm 96dB+17.5dBm 98dB >> 15kHz +22dBm 103dB+12.5dBm 96dB+22dBm 101dB >> 20kHz +22dBm 103dB+12.5dBm 96dB+25dBm 103dB >> 30kHz +22dBm 103dB+12.5dBm 96dB+26.5dBm 104dB >> 40kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB >> 50kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB >> > > Yes, and also the 8-pole 1.8k should be better than the 5-pole 2.7k. Some > very strange results indeed but I'm sure Peter is reporting what he's > measuring. I cannot find his original Orion review but I recall it showed > the 2.4k 4-pole and 1.8k 8-pole to be much better than the 1.0k 4-pole at > 2 kHz spacings, which again did not make sense unless the 1k filter was > defective. > > 73, Bill > > -- View this message in context: http://www.nabble.com/RSGB-RadCom-K3-review-posted-on-RSGB-Members-web-page-tp17869976p17981961.html Sent from the Elecraft mailing list archive at Nabble.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] RSGB RadCom K3 review posted on RSGB Members web page
Jan Erik Holm wrote: > > Yes something isn´t right. This was his measurements: > > CLOSE-IN INTERMODULATION ON 7MHz band,500Hz bandwidth, CW preamp off > > 2.7 kHz roofing 1.8 kHz roofing 500 Hz roofing > 2kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB > 3kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB > 5kHz +22dBm 103dB+12.5dBm 96dB+8.5dBm 92dB > 7kHz +22dBm 103dB+12.5dBm 96dB+13dBm95dB > 10kHz +22dBm 103dB+12.5dBm 96dB+17.5dBm 98dB > 15kHz +22dBm 103dB+12.5dBm 96dB+22dBm 101dB > 20kHz +22dBm 103dB+12.5dBm 96dB+25dBm 103dB > 30kHz +22dBm 103dB+12.5dBm 96dB+26.5dBm 104dB > 40kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB > 50kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB > Yes, and also the 8-pole 1.8k should be better than the 5-pole 2.7k. Some very strange results indeed but I'm sure Peter is reporting what he's measuring. I cannot find his original Orion review but I recall it showed the 2.4k 4-pole and 1.8k 8-pole to be much better than the 1.0k 4-pole at 2 kHz spacings, which again did not make sense unless the 1k filter was defective. 73, Bill -- View this message in context: http://www.nabble.com/RSGB-RadCom-K3-review-posted-on-RSGB-Members-web-page-tp17869976p17980475.html Sent from the Elecraft mailing list archive at Nabble.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] RSGB RadCom K3 review posted on RSGB Members web page
Yes something isn´t right. This was his measurements: CLOSE-IN INTERMODULATION ON 7MHz band,500Hz bandwidth, CW preamp off 2.7 kHz roofing 1.8 kHz roofing 500 Hz roofing 2kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB 3kHz +19dBm 101dB+12.5dBm 96dB+2.5dBm 88dB 5kHz +22dBm 103dB+12.5dBm 96dB+8.5dBm 92dB 7kHz +22dBm 103dB+12.5dBm 96dB+13dBm95dB 10kHz +22dBm 103dB+12.5dBm 96dB+17.5dBm 98dB 15kHz +22dBm 103dB+12.5dBm 96dB+22dBm 101dB 20kHz +22dBm 103dB+12.5dBm 96dB+25dBm 103dB 30kHz +22dBm 103dB+12.5dBm 96dB+26.5dBm 104dB 40kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB 50kHz +22dBm 103dB+12.5dBm 96dB+27dBm 104dB He also wrote this: Third order intercept and dynamic range results were excellent, but results were a little dependent on which roofing filter was in circuit (see table). With the stock 2.7kHz filter, the intermodulation limited dynamic range held at over 100dB (in 500Hz DSP bandwidth) down to 2kHz spacing, probably the highest figure I have ever measured at this spacing. However, with the 500Hz 5 pole roofing filter, a degradation was seen at close spacings and non-linear effects such as hysteresis were also observed. A step drop in performance was triggered as the spacing was reduced, which did not follow the reverse pattern as the spacing was again increased. Now if something similar did happen in the Orion case a measurement error can be suspected. It isn´t logical to think two bad filters. de SM2EKM . Bill W4ZV wrote: Jan Erik Holm wrote: Interesting review. Considering IMDDR3 it seems like one should stay way from the 500 Hz filter, looks like the 400 Hz is the filter to get. I haven't read the review but he must have had a bad 500 Hz filter from what I've heard reported (i.e. the 2.7k better than the 500 Hz). That makes no sense and is contradictory to previous measurements by both Elecraft and Sherwood: Elecraft: Filter20kHz 10kHz 5kHz 2kHz 200 Hz, 5 pole100+ 100+ 100+ 95 250 Hz, 8 pole100+ 100+ 100+ 95 400 Hz, 8 pole100+ 100+ 100+ 95 500 Hz, 5 pole100+ 100+ 100+ 94 1 kHz, 8 pole 100+ 100+ 10094 2.7 kHz, 5 pole 100+ 98 92n/a 2.8 kHz, 8 pole 100+ 100 93n/a http://www.zerobeat.net/mediawiki/index.php/K3_Roofing_Filters Sherwood: Filter - IMD @ 2 kHz 500 Hz - 95 dB 400 Hz - 96 dB 200 Hz - 101 dB* *I listed the 200 Hz because it's a 5-pole filter (just like the 500 Hz) in case some believe there is an inherent problem with 5-pole filters. http://www.sherweng.com/table.html It's odd but Peter Hart reported something similar when he did Orion's review. The 2.4k filter was much better than the 1.0k, which again makes no sense unless the 1.0k was defective. I'm sure Peter reported what he measured but common sense would dictate that one should suspect something was wrong with the filter and request another when anomalous results like this are measured. It also reminds me when ARRL once reported better IMD performance with Preamp ON versus Preamp OFF. Common sense would say "TILT"! 73, Bill W4ZV ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
Jan Erik Holm wrote: > > Interesting review. > > Considering IMDDR3 it seems like one should stay > way from the 500 Hz filter, looks like the 400 Hz > is the filter to get. > I haven't read the review but he must have had a bad 500 Hz filter from what I've heard reported (i.e. the 2.7k better than the 500 Hz). That makes no sense and is contradictory to previous measurements by both Elecraft and Sherwood: Elecraft: Filter20kHz 10kHz 5kHz 2kHz 200 Hz, 5 pole100+ 100+ 100+ 95 250 Hz, 8 pole100+ 100+ 100+ 95 400 Hz, 8 pole100+ 100+ 100+ 95 500 Hz, 5 pole100+ 100+ 100+ 94 1 kHz, 8 pole 100+ 100+ 10094 2.7 kHz, 5 pole 100+ 98 92n/a 2.8 kHz, 8 pole 100+ 100 93n/a http://www.zerobeat.net/mediawiki/index.php/K3_Roofing_Filters Sherwood: Filter - IMD @ 2 kHz 500 Hz - 95 dB 400 Hz - 96 dB 200 Hz - 101 dB* *I listed the 200 Hz because it's a 5-pole filter (just like the 500 Hz) in case some believe there is an inherent problem with 5-pole filters. http://www.sherweng.com/table.html It's odd but Peter Hart reported something similar when he did Orion's review. The 2.4k filter was much better than the 1.0k, which again makes no sense unless the 1.0k was defective. I'm sure Peter reported what he measured but common sense would dictate that one should suspect something was wrong with the filter and request another when anomalous results like this are measured. It also reminds me when ARRL once reported better IMD performance with Preamp ON versus Preamp OFF. Common sense would say "TILT"! 73, Bill W4ZV -- View this message in context: http://www.nabble.com/RSGB-RadCom-K3-review-posted-on-RSGB-Members-web-page-tp17869976p17958106.html Sent from the Elecraft mailing list archive at Nabble.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] RSGB RadCom K3 review posted on RSGB Members web page
H! Makes me feel like I knew something when I decided to get the 400 hz filter instead of the 500 hz filter! As far as power settings, I usually like to follow a self imposed rule of never running a transceiver at more than 85% of "maximum". It probably is meaningless in many cases as far as really being a safety valve, but I figure that less than maximum strain ought to have some beneficial effect on the finals, etc. It probably sounds very arbitrary, but I follow this same rule in lots of things--even other than ham radio. In golf, for instance, I find that swinging the club at about 80-85% of what might be my maximum results in better contact and consistency. As far as the receiving station is concerned, 80 or 85 watts vs. 100 watts should be imperceptible. Although the K3 may not be one of them, there are lots of rigs out there that are very closely spec'd, either as to the finals, or the filters, etc. Some rigs have lots of "cushion"--the older TS-50 comes to mind, which apparently could easily run 200 watts or more with the finals in that rig. Some folks were actually cranking them up to that or higher! But nobody seemed to be too concerned about what the bandpass filters could handle, etc., and that bothered me enough to resist the temptation. So, I usually set my K3 at around 85 watts if I'm running QRO. Ignorance is bliss sometimes! Dave W7AQK - Original Message - From: "Jan Erik Holm" <[EMAIL PROTECTED]> Cc: Sent: Monday, June 16, 2008 10:19 PM Subject: Re: [Elecraft] RSGB RadCom K3 review posted on RSGB Members web page Interesting review. Considering IMDDR3 it seems like one should stay way from the 500 Hz filter, looks like the 400 Hz is the filter to get. Also the TX probably shouldn´t be cranked up to 120W but instead 100W should be maximum. 73 Jim SM2EKM -- Dave G4AON wrote: For those who are RSGB members, see: http://www.rsgb.org/membersonly/publications/reviews/index.php The K3 review by Peter Hart has just been posted. As it is copyright RSGB, so I can't quote much of it, but Peter concludes with: "The K3 is an impressive radio, which has attracted much interest and orders. One of the leading radios for close-in dynamic range and with excellent features, it is an ideal radio for use at home, field day or DXpeditions" 73 Dave, G4AON K3/100 #80 ___ 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 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] RSGB RadCom K3 review posted on RSGB Members web page
Interesting review. Considering IMDDR3 it seems like one should stay way from the 500 Hz filter, looks like the 400 Hz is the filter to get. Also the TX probably shouldn´t be cranked up to 120W but instead 100W should be maximum. 73 Jim SM2EKM -- Dave G4AON wrote: For those who are RSGB members, see: http://www.rsgb.org/membersonly/publications/reviews/index.php The K3 review by Peter Hart has just been posted. As it is copyright RSGB, so I can't quote much of it, but Peter concludes with: "The K3 is an impressive radio, which has attracted much interest and orders. One of the leading radios for close-in dynamic range and with excellent features, it is an ideal radio for use at home, field day or DXpeditions" 73 Dave, G4AON K3/100 #80 ___ 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] RSGB RadCom K3 review posted on RSGB Members web page
Dave G4AON wrote: For those who are RSGB members, see: http://www.rsgb.org/membersonly/publications/reviews/index.php The K3 review by Peter Hart has just been posted. As it is copyright RSGB, so I can't quote much of it, but Peter concludes with: "The K3 is an impressive radio, which has attracted much interest and orders. One of the leading radios for close-in dynamic range and with excellent features, it is an ideal radio for use at home, field day or DXpeditions" Hopefully Elecraft will obtain permission from RSGB to post the review publicly, as happened with the QST review. Most of the five pages are taken up by a description of the K3, which will be very familiar to existing users. The really interesting parts are towards the end, the on-air impressions and the measurements - although here too, many of the issues are familiar. One important thing to add is that the review would have been written *before* the major MCU 1.87 / DSP 1.69 update released on May 3rd, so Peter did not see the K3 in its current state of performance. -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek ___ 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
