6M Preamp
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While having a 6-meter preamplifier may help when signals are weak, if the band well and truly opens, signals will be so strong that overload will be most operator's main problem. Remember that during the openings of 1948 and 1959, many stations managed to work WAS with transmitters that put out less than 10 watts (Gonset "Communicators" and the like) and had receivers where a 10 db noise figure was considered good, and many were much worse, plus many were using very simple antennas (eg: a ground-plane vertical). Up this way, Tim, KL7WE (SK) did indeed work WAS (from Alaska) with a barefoot 2 to 3 watt output ICOM IC-502 set in the 1970's. Not trying to discourage anyone from having a preamplifier available, but just mentioning that with a bit of patience, a "stock" radio may be all you need. - Jim, KL7CC > _______________________________________________ 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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Yes, the 502, I had one of those and worked with the built in antenna to
great results with 2 watts. The K3 has some good noise filtering and the filters are helpful. I have two other radios capable of 6 meters and have not done a comparison. Bill -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Jim Wiley Sent: Thursday, October 23, 2008 3:32 PM To: Greg-N4CC Cc: [hidden email] Subject: Re: [Elecraft] 6M Preamp While having a 6-meter preamplifier may help when signals are weak, if the band well and truly opens, signals will be so strong that overload will be most operator's main problem. Remember that during the openings of 1948 and 1959, many stations managed to work WAS with transmitters that put out less than 10 watts (Gonset "Communicators" and the like) and had receivers where a 10 db noise figure was considered good, and many were much worse, plus many were using very simple antennas (eg: a ground-plane vertical). Up this way, Tim, KL7WE (SK) did indeed work WAS (from Alaska) with a barefoot 2 to 3 watt output ICOM IC-502 set in the 1970's. Not trying to discourage anyone from having a preamplifier available, but just mentioning that with a bit of patience, a "stock" radio may be all you need. - Jim, KL7CC _______________________________________________ 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 Julian, G4ILO
As some one who bought the K3 purely for it's RX performance on 6m, can some
one tell me once and for all if it is as good as, or better/worse than, other radios like the Icom 756 pro etc... It was my understanding from information provided that it was, is this not the case?? 73 Andy http://www.gd0tep.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Julian, G4ILO Sent: 23 October 2008 19:52 To: [hidden email] Subject: RE: [Elecraft] 6M Preamp Joe Subich, W4TV-3 wrote: > > I don't know that you can say performance on six meters should > have been higher than the performance on the HF bands. There > are probably more K3 users who will never use six meters in any > serious way than those who will. However, the Elecraft preamp > does represent a substantial premium for RX Loop pass-through and > ease of integration. Whether the premium is justified is a > decision for the user and the option allows those who need it > to get the performance without taxing those who will never benefit > from it. > the performance on the HF bands. I'm saying that it should not be worse than an IC-756 PRO III, a TS-2000 or an FT-2000 would be, considering the claims made about the K3's performance. I have no idea of the proportion of K3 users who will never use 6 meters in any serious way. However I think there are quite a few, such as myself, who will have some fun on the band from time to time simply because modern HF transceivers now include it. I'm certainly not serious enough about 6m to spend money on a preamp for it, so I'm feeling a little short-changed after receiving information that the K3 is so deaf on 6m that you need one. The other radios mentioned above certainly are usable on 6m without a preamp by all but the most diehard enthusiast who would probably want it at the masthead anyway. ----- Julian, G4ILO. K2 #392 K3 #222. http://www.g4ilo.com/ G4ILO's Shack http://www.ham-directory.com/ Ham Directory http://www.g4ilo.com/kcomm.html KComm for Elecraft K2 and K3 -- View this message in context: http://n2.nabble.com/6M-Preamp-tp1366337p1369367.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.175 / Virus Database: 270.8.2/1741 - Release Date: 23/10/2008 07:54 _______________________________________________ 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 Julian, G4ILO
> I'm not saying that performance on six meters should have > been higher than the performance on the HF bands. I'm saying > that it should not be worse than an IC-756 PRO III, a TS-2000 > or an FT-2000 would be, considering the claims made about the > K3's performance. No, you are asking for a lower MDS than on HF without regard to the overall performance of the radio in terms of dynamic range. There are many K3 users who rely on dynamic range and freedom from interference on HF that blows away any of the radios you list. Even on six meters they K3 dynamic range far exceeds that of the YaeComWood radios you cite. Above all, your information concerning sensitivity is just plain wrong. The ARRL Lab data shows the FT-2000 sensitivity (MDS) on 50 MHz (preamp off) at -122 dBm ... and measures the K3 MDS at -128 dBm (preamp off). Similarly, with "preamp 1" the FT-2000 measured at -131 dBm vs. -135 dBm for the K3 (internal preamp). If you want to compare the TS-2000, its MDS (preamp off) is -127 dBm rising to -142 dBm with preamp on but with a dynamic range of only 66dB (worse than a 30 year old FT-101!). To complete your comparisons, the Icom has the same -136 dBm MDS with "preamp 1" and a dynamic range of only 74 dB. I would say that Eric and Wayne made exactly the right design decisions with a -136 dBm MDS and 100 dB dynamic range. Yes, the K3's MDS is slightly worse on 50 MHz than on 14 MHz due to the additional filtering in the front end. However, even with a lousy vertical antenna, my receiver noise always increases by at least 2 dB when switching from a dummy load to the antenna. A second higher gain, preamplifier would be of no value to the vast majority of K3 users ... in fact it would likely be counter- productive as it would harm the excellent dynamic range of the radio. Why should those who have no need for the ultra high sensitivity on a band they rarely use subsidize performance that benefits only a limited few? > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Julian, G4ILO > Sent: Thursday, October 23, 2008 2:52 PM > To: [hidden email] > Subject: RE: [Elecraft] 6M Preamp > > > > > > Joe Subich, W4TV-3 wrote: > > > > I don't know that you can say performance on six meters should > > have been higher than the performance on the HF bands. There > > are probably more K3 users who will never use six meters in any > > serious way than those who will. However, the Elecraft preamp > > does represent a substantial premium for RX Loop pass-through and > > ease of integration. Whether the premium is justified is a > > decision for the user and the option allows those who need it > > to get the performance without taxing those who will never benefit > > from it. > > > I'm not saying that performance on six meters should have > been higher than the performance on the HF bands. I'm saying > that it should not be worse than an IC-756 PRO III, a TS-2000 > or an FT-2000 would be, considering the claims made about the > K3's performance. > > I have no idea of the proportion of K3 users who will never > use 6 meters in any serious way. However I think there are > quite a few, such as myself, who will have some fun on the > band from time to time simply because modern HF transceivers > now include it. I'm certainly not serious enough about 6m to > spend money on a preamp for it, so I'm feeling a little > short-changed after receiving information that the K3 is so > deaf on 6m that you need one. The other radios mentioned > above certainly are usable on 6m without a preamp by all but > the most diehard enthusiast who would probably want it at the > masthead anyway. > > ----- > Julian, G4ILO. K2 #392 K3 #222. > http://www.g4ilo.com/ G4ILO's Shack > http://www.ham-directory.com/ Ham > Directory http://www.g4ilo.com/kcomm.html KComm for > Elecraft K2 and K3 > -- > View this message in context: > http://n2.nabble.com/6M-Preamp-tp1366337p1369367.html > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Because the K3 is advertised as a "high performance 160-6m transceiver", not a "high performance 160-10m transceiver with 6m coverage at a lower level of performance." I don't see why good 6m receive performance is necessarily incompatible with good HF dynamic range. Preamps can be switched out, and some Japanese made radios I believe have separate preamps for their VHF bands. Wayne has explained why the sensitivity on 6m is not as good as on other bands and it is clear that this is as a result of a design compromise made on the basis that HF performance was paramount. As someone else in this thread pointed out, this compromise is not something that is widely publicised, and it might have affected some people's purchase decisions. I might not have sold the 6m transverter I used with my K2 if I had known that the K3 was not going to have the superior performance on all bands that I thought it was going to have. Still, I'm glad to hear from other contributors to this thread who have said that they have found the stock K3 just fine. Given that I'm in a fairly noisy urban environment, perhaps the preamp would have been a waste of money for me anyway.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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In reply to this post by gd0tep
gd0tep wrote:
>As some one who bought the K3 purely for it's RX performance on 6m, can >some one tell me once and for all if it is as good as, or better/worse >than, other radios like the Icom 756 pro etc... It was my understanding >from information provided that it was, is this not the case?? The K3's sensitivity specification corresponds to a noise figure of about 13dB. My K3 meets its sensitivity spec almost exactly, but at this site it can barely hear antenna noise on 6m. By contrast, the old IC-746 hears 6m antenna noise easily because it has a VHF-optimized preamp built in. Even that ageing mid-range rig has a choice of two different preamps (and a third dedicated to 2m). Of course it's still possible to work lots of weak DX on 6m using the standard K3 receiver; but in the limit, some QSOs will be lost that could have been completed with a more sensitive receiver. The K3 with a preamp is probably the best 6m receiver available; but this high-end rig should have included a competent 6m preamp and bypass relays on the original KVXV3 board, and not as a clumsy afterthought. -- 73 from Ian GM3SEK _______________________________________________ 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 Julian, G4ILO
On Thu, 2008-10-23 at 05:05 -0700, Julian, G4ILO wrote:
> I can always use the FT-817. Just how deaf is the K3 on 6m really, anyway? Not very deaf at all. It's just not capable of hearing to the thermal nose floor at a good setup. Having said that Stock K3's have managed EME contacts so it's not far off and the stock K3 is definitely better on 6m than many of the other mid priced HF+6m, radios out there and runs veritable rings around the 817 on 6m in the sensitivity stakes. Adding the preamp here ( I am one of the 6m-pre beta testers) to my good set-up (7 element long yagi in a very quiet rural location) helps by a couple of dB, well worth having for weak signal work but makes no difference for 95% of my 6m Contacts If your local noise floor is not quiet then the 6m pre won't help a bit. A quick test is does the received nose level drop significantly (several dB) when you switch from your antenna to a 50Ohm Dummy load? If so then it is unlikely a preamp will help. 73 Brendan -- Don‘t complain. Nobody will understand. Or care. And certainly don‘t try to fix the situation yourself. It‘s dangerous. Leave it to a highly untrained, unqualified, expendable professional. _______________________________________________ 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 gm3sek
> The K3's sensitivity specification corresponds to a noise figure > of about 13dB. My K3 meets its sensitivity spec almost exactly, That's the point. The K3 meets its specifications. > The K3 with a preamp is probably the best 6m receiver available; > but this high-end rig should have included a competent 6m preamp > and bypass relays on the original KVXV3 board, and not as a clumsy > afterthought. You will never get agreement as to what should be included in the KXV3 (transverter board) or the overall "package." Low band fans will tell you the transceiver should include full receive antenna switching (e.g., relays to allow the KRX3 to use the transmit antenna while the main receiver uses the RX antenna and/or allow each receiver to use a different low noise receive antenna. There is simply is no room for the "other" functions on the KXV3 and no justification for adding the extra cost (and operational complexity) for features that will only be used by a small fraction of users. Elecraft have struck an excellent balance - designing a rig with an equal level of performance across the operating range and providing an interface (KXV3) that allows those who want additional performance or features (better rx antenna switching, higher sensitivity on 50 MHz, UHF/VHF transverters, KRX3, etc.) to add them as needed and at reasonable cost. > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Ian > White GM3SEK > Sent: Thursday, October 23, 2008 6:23 PM > To: [hidden email] > Subject: Re: [Elecraft] 6M Preamp > > > gd0tep wrote: > >As some one who bought the K3 purely for it's RX performance > on 6m, can > >some one tell me once and for all if it is as good as, or > better/worse > >than, other radios like the Icom 756 pro etc... It was my > understanding > >from information provided that it was, is this not the case?? > > The K3's sensitivity specification corresponds to a noise figure of > about 13dB. My K3 meets its sensitivity spec almost exactly, > but at this > site it can barely hear antenna noise on 6m. > > By contrast, the old IC-746 hears 6m antenna noise easily > because it has > a VHF-optimized preamp built in. Even that ageing mid-range rig has a > choice of two different preamps (and a third dedicated to 2m). > > Of course it's still possible to work lots of weak DX on 6m using the > standard K3 receiver; but in the limit, some QSOs will be lost that > could have been completed with a more sensitive receiver. > > The K3 with a preamp is probably the best 6m receiver available; but > this high-end rig should have included a competent 6m preamp > and bypass > relays on the original KVXV3 board, and not as a clumsy afterthought. > > > > -- > > 73 from Ian GM3SEK _______________________________________________ > 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 Julian, G4ILO
Julian,
".... clear that this is as a result of a design compromise made on the basis that HF performance was paramount" I don't think it was a compromise, if it was intentional to keep performance at peak. Weak signal work usually requires preamp at the antenna not at the radio, and personally I'd rather have the focus on MDS with excellent ears. The excellent ears without MDS are useless in high noise and strong adjacent sigs. 73, Bill K9YEQ K2 #35; KX1 #35; K3 #1744; mini mods -----Original Message----- Still, I'm glad to hear from other contributors to this thread who have said that they have found the stock K3 just fine. Given that I'm in a fairly noisy urban environment, perhaps the preamp would have been a waste of money for me anyway. ----- Julian, G4ILO. K2 #392 K3 #222. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Joe Subich, W4TV-3
Amen Joe. It is amazing the gripes you hear and the justifications for
them. The specs were advertised; if you didnt like them, why did you purchase a K3? I am a very satisfied K3 customer and I have used the K3 to work weak dx on all the bands 160-6 meters.......... Jim K4JAF ----- Original Message ----- From: "Joe Subich, W4TV" <[hidden email]> To: "'Ian White GM3SEK'" <[hidden email]>; <[hidden email]> Sent: Thursday, October 23, 2008 5:57 PM Subject: RE: [Elecraft] 6M Preamp > > >> The K3's sensitivity specification corresponds to a noise figure >> of about 13dB. My K3 meets its sensitivity spec almost exactly, > > That's the point. The K3 meets its specifications. > >> The K3 with a preamp is probably the best 6m receiver available; >> but this high-end rig should have included a competent 6m preamp >> and bypass relays on the original KVXV3 board, and not as a clumsy >> afterthought. > > You will never get agreement as to what should be included in > the KXV3 (transverter board) or the overall "package." Low band > fans will tell you the transceiver should include full receive > antenna switching (e.g., relays to allow the KRX3 to use the > transmit antenna while the main receiver uses the RX antenna > and/or allow each receiver to use a different low noise receive > antenna. There is simply is no room for the "other" functions > on the KXV3 and no justification for adding the extra cost (and > operational complexity) for features that will only be used by > a small fraction of users. > > Elecraft have struck an excellent balance - designing a rig > with an equal level of performance across the operating range > and providing an interface (KXV3) that allows those who want > additional performance or features (better rx antenna switching, > higher sensitivity on 50 MHz, UHF/VHF transverters, KRX3, etc.) > to add them as needed and at reasonable cost. > > > > >> -----Original Message----- >> From: [hidden email] >> [mailto:[hidden email]] On Behalf Of Ian >> White GM3SEK >> Sent: Thursday, October 23, 2008 6:23 PM >> To: [hidden email] >> Subject: Re: [Elecraft] 6M Preamp >> >> >> gd0tep wrote: >> >As some one who bought the K3 purely for it's RX performance >> on 6m, can >> >some one tell me once and for all if it is as good as, or >> better/worse >> >than, other radios like the Icom 756 pro etc... It was my >> understanding >> >from information provided that it was, is this not the case?? >> >> The K3's sensitivity specification corresponds to a noise figure of >> about 13dB. My K3 meets its sensitivity spec almost exactly, >> but at this >> site it can barely hear antenna noise on 6m. >> >> By contrast, the old IC-746 hears 6m antenna noise easily >> because it has >> a VHF-optimized preamp built in. Even that ageing mid-range rig has a >> choice of two different preamps (and a third dedicated to 2m). >> >> Of course it's still possible to work lots of weak DX on 6m using the >> standard K3 receiver; but in the limit, some QSOs will be lost that >> could have been completed with a more sensitive receiver. >> >> The K3 with a preamp is probably the best 6m receiver available; but >> this high-end rig should have included a competent 6m preamp >> and bypass >> relays on the original KVXV3 board, and not as a clumsy afterthought. >> >> >> >> -- >> >> 73 from Ian GM3SEK _______________________________________________ >> 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 _______________________________________________ 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 W7GJ, Lance
Hi all,
Personally I wish Elecraft had resisted the temptation to include the 6m band in the K3. Grafting the 6m band, which is a VHF band, on to a HF transceiver will always be a compromise at best and at worst it might affect HF performance negatively. In my opinion ICOM made a good choice in their low end transceivers (IC-718, IC-7200) to eliminate 6m and FM mode. Both choices are generally unneeded by HF operators and both make good engineering optimizations possible for the mainstream HF modes. Knut - AB2TC
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In reply to this post by Jim Cox
I believe the right to freedom of speech extends to this reflector, Jim. I think Elecraft themselves may have inadvertently helped to feed the impression that the K3 was below par on 6m by rushing out an accessory preamp that was not announced at the time of the K3 launch, even ahead of accessories that were announced then such as the voice recorder. I have even had the opinion expressed to me privately that since the preamp was "necessary" Elecraft ought to be providing it free of charge to existing customers! Therefore I make no apology for raising this matter. I hope that others have found the ensuing thread informative and ultimately reassuring that the external preamp is only necessary for those who require the ultimate performance - just as with any other transceiver. I believe the K3 would not be as good as it is today if the only feedback Elecraft got from its customers was fanboy adulation.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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