6 Meters
Locked
12
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I purchased a used
FT 100 just to monitor 6 while using the other bands with the K3. Today
there is a great opening. Signals are screaming from the FT 100 and hardly
heard on the K3 using an antenna switch. Guess I better get a Preamp in
line quickly.
Phil
Philip
LaMarche www.w9dvm.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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On Sun, 25 Jan 2009 12:34:03 -0500
"Phil LaMarche" <[hidden email]> wrote: > I purchased a used FT 100 just to monitor 6 while using the other bands with > the K3. Today there is a great opening. Signals are screaming from the FT > 100 and hardly heard on the K3 using an antenna switch. Guess I better get > a Preamp in line quickly. > > Phil > > > Philip LaMarche > LaMarche Enterprises, Inc. > <http://www.instantgourmetspices.com/> www.instantgourmetspices.com > > www.w9dvm.com <http://www.w9dvm.com/> > 800-395-7795 pin 02 > 727-944-3226 >FAX 727-937-8834 > NASFT 30210 > W9DVM Phil, You're right about the 6mtr. band being practically deaf in the K3!!! I did order the 6m. preamp because of that short-coming! But you would have thought that the BOYZ @ Elecraft would'nt have short-changed 6m sensitivity as ALL THE OTHER BANDS HEAR WELL!!! Why build a quality rig if one-band is only added as a "after-thought"??? Jim/nn6ee S/N 2406 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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What's so amazing is that others tell me how good their K3 is on 6. This is a unit built by AB7R who is tops with Elecraft and it was checked out before selling. The other bands are wonderful. Just a point, my Flex 1000 and Flex 5000 was the same way and part of the reason I switched. Still happy I did, especially with the Lp Pan which emulates Flex. BUT to have an old 400 buck FT100 body slam it is quite puzzling. Phil Philip LaMarche LaMarche Enterprises, Inc. www.instantgourmetspices.com www.w9dvm.com 800-395-7795 pin 02 727-944-3226 FAX 727-937-8834 NASFT 30210 W9DVM -----Original Message----- From: JIM DAVIS [mailto:[hidden email]] Sent: Sunday, January 25, 2009 2:12 PM To: Phil LaMarche; [hidden email] Subject: Re: [Elecraft] 6 Meters On Sun, 25 Jan 2009 12:34:03 -0500 "Phil LaMarche" <[hidden email]> wrote: > I purchased a used FT 100 just to monitor 6 while using the other > bands with the K3. Today there is a great opening. Signals are > screaming from the FT 100 and hardly heard on the K3 using an antenna > switch. Guess I better get a Preamp in line quickly. > > Phil > > > Philip LaMarche > LaMarche Enterprises, Inc. > <http://www.instantgourmetspices.com/> www.instantgourmetspices.com > > www.w9dvm.com <http://www.w9dvm.com/> > 800-395-7795 pin 02 > 727-944-3226 >FAX 727-937-8834 > NASFT 30210 > W9DVM ***** Phil, You're right about the 6mtr. band being practically deaf in the K3!!! I did order the 6m. preamp because of that short-coming! But you would have thought that the BOYZ @ Elecraft would'nt have short-changed 6m sensitivity as ALL THE OTHER BANDS HEAR WELL!!! Why build a quality rig if one-band is only added as a "after-thought"??? Jim/nn6ee S/N 2406 _______________________________________________ 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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Phil, Jim, others ...
I've been using my K3 on 6M with good
results. It hears
well, even without a preamp in my quiet
location. I did
add a DEM preamp which, of course "helped" a bit,
but
-not- to the extent that I was able to hear
anything I could
not already hear with the basic K3.
When they became available added the PR6 just to "keep
it in the family" and it works well. I sold the DEM
pre-amp
to a local friend with a K3.
73! Ken Kopp - K0PP
_______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Phil LaMarche-2
Very strange. Went to 6 on the K3 and my speaker was full of signals. Worked Texas and Mexico with +9 signals. This morning the 100 heard everything and when switched to K3, hardly anything. Maybe the K3 gods helped. I have 5 elements at 80 ft. Phil Philip LaMarche LaMarche Enterprises, Inc. www.instantgourmetspices.com www.w9dvm.com 800-395-7795 pin 02 727-944-3226 FAX 727-937-8834 NASFT 30210 W9DVM -----Original Message----- From: Jack Colson [mailto:[hidden email]] Sent: Sunday, January 25, 2009 3:10 PM To: Phil LaMarche Subject: Re: [Elecraft] 6 Meters 50.062 SW of Ocala. Down South in EL86 is W9DR and if I recall he is on about 071. I am hearing a TI and XE beacons now on 6 with my beam pointed NE. Good luck. ----- Original Message ----- From: "Phil LaMarche" <[hidden email]> To: "'Jack Colson'" <[hidden email]> Sent: Sunday, January 25, 2009 3:06 PM Subject: RE: [Elecraft] 6 Meters > > Thank you. Do you know the frequency? > > Phil > > > Philip LaMarche > LaMarche Enterprises, Inc. > www.instantgourmetspices.com > > www.w9dvm.com > 800-395-7795 pin 02 > 727-944-3226 > FAX 727-937-8834 > NASFT 30210 > W9DVM > > > > -----Original Message----- > From: Jack Colson [mailto:[hidden email]] > Sent: Sunday, January 25, 2009 2:52 PM > To: Phil LaMarche > Subject: Re: [Elecraft] 6 Meters > > Phil have you found a CW beacon to listen to on 6 meters? There are > several in range of Tampa. I have a homebuilt pre-amp for 6 and it > does make a difference but I can still copy the weak signals w/o the > external amp in the shack. I have a FT-100D and it is a very hot > receiver. If you look at the Sherwood measurements that is quite > obvious. > > 73 > Jack > ----- Original Message ----- > From: "Phil LaMarche" <[hidden email]> > To: "'JIM DAVIS'" <[hidden email]>; <[hidden email]> > Sent: Sunday, January 25, 2009 2:37 PM > Subject: Re: [Elecraft] 6 Meters > > >> >> What's so amazing is that others tell me how good their K3 is on 6. >> This is >> a unit built by AB7R who is tops with Elecraft and it was checked out >> before >> selling. The other bands are wonderful. Just a point, my Flex 1000 >> and >> Flex 5000 was the same way and part of the reason I switched. Still >> happy I >> did, especially with the Lp Pan which emulates Flex. BUT to have an >> old 400 >> buck FT100 body slam it is quite puzzling. >> >> Phil >> >> >> Philip LaMarche >> LaMarche Enterprises, Inc. >> www.instantgourmetspices.com >> >> www.w9dvm.com >> 800-395-7795 pin 02 >> 727-944-3226 >> FAX 727-937-8834 >> NASFT 30210 >> W9DVM >> >> >> >> -----Original Message----- >> From: JIM DAVIS [mailto:[hidden email]] >> Sent: Sunday, January 25, 2009 2:12 PM >> To: Phil LaMarche; [hidden email] >> Subject: Re: [Elecraft] 6 Meters >> >> On Sun, 25 Jan 2009 12:34:03 -0500 >> "Phil LaMarche" <[hidden email]> wrote: >>> I purchased a used FT 100 just to monitor 6 while using the other >>> bands with the K3. Today there is a great opening. Signals are >>> screaming from the FT 100 and hardly heard on the K3 using an >>> antenna >>> switch. Guess I better get a Preamp in line quickly. >>> >>> Phil >>> >>> >>> Philip LaMarche >>> LaMarche Enterprises, Inc. >>> <http://www.instantgourmetspices.com/> www.instantgourmetspices.com >>> >>> www.w9dvm.com <http://www.w9dvm.com/> >>> 800-395-7795 pin 02 >>> 727-944-3226 >>>FAX 727-937-8834 >>> NASFT 30210 >>> W9DVM >> > >> ***** >> >> Phil, >> >> You're right about the 6mtr. band being practically deaf in the K3!!! >> I did >> order the 6m. preamp because of that short-coming! But you would have >> thought that the BOYZ @ Elecraft would'nt have short-changed 6m >> sensitivity >> as ALL THE OTHER BANDS HEAR WELL!!! >> >> Why build a quality rig if one-band is only added as a >> "after-thought"??? >> >> Jim/nn6ee >> S/N 2406 >> >> >> >> >> >> _______________________________________________ >> 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 Phil LaMarche-2
Hummm that is indeed weird. When this was bought up last summer I thought
my K3 must be special as I kept it on 6m the whole summer. I would switch back and forth between rigs and never found the K3 lacking. Could be my simple setup? Not much feedline loss, the antenna is very low to the ground and near the shack. Probably not over 25 feet of feedline. 73 de jay/w5jay.. > > What's so amazing is that others tell me how good their K3 is on 6. This > is > a unit built by AB7R who is tops with Elecraft and it was checked out > before > selling. The other bands are wonderful. Just a point, my Flex 1000 and > Flex 5000 was the same way and part of the reason I switched. Still happy > I > did, especially with the Lp Pan which emulates Flex. BUT to have an old > 400 > buck FT100 body slam it is quite puzzling. > > Phil > > > Philip LaMarche > LaMarche Enterprises, Inc. > www.instantgourmetspices.com > > www.w9dvm.com > 800-395-7795 pin 02 > 727-944-3226 > FAX 727-937-8834 > NASFT 30210 > W9DVM > > > > -----Original Message----- > From: JIM DAVIS [mailto:[hidden email]] > Sent: Sunday, January 25, 2009 2:12 PM > To: Phil LaMarche; [hidden email] > Subject: Re: [Elecraft] 6 Meters > > On Sun, 25 Jan 2009 12:34:03 -0500 > "Phil LaMarche" <[hidden email]> wrote: >> I purchased a used FT 100 just to monitor 6 while using the other >> bands with the K3. Today there is a great opening. Signals are >> screaming from the FT 100 and hardly heard on the K3 using an antenna >> switch. Guess I better get a Preamp in line quickly. >> >> Phil >> >> >> Philip LaMarche >> LaMarche Enterprises, Inc. >> <http://www.instantgourmetspices.com/> www.instantgourmetspices.com >> >> www.w9dvm.com <http://www.w9dvm.com/> >> 800-395-7795 pin 02 >> 727-944-3226 >>FAX 727-937-8834 >> NASFT 30210 >> W9DVM > **************************************************************************** > ***** > > Phil, > > You're right about the 6mtr. band being practically deaf in the K3!!! I > did > order the 6m. preamp because of that short-coming! But you would have > thought that the BOYZ @ Elecraft would'nt have short-changed 6m > sensitivity > as ALL THE OTHER BANDS HEAR WELL!!! > > Why build a quality rig if one-band is only added as a "after-thought"??? > > Jim/nn6ee > S/N 2406 > > > > > > _______________________________________________ > 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 JIM DAVIS-11
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In reply to this post by Phil LaMarche-2
My K3 hears just fine. I compared it to the receiver in my IC-7800 today on an XE2 from DL95 slipping into EM48. The K3 heard just as well, and actually handled my line noise on 6M better. I listened using the PR6 with the rig preamp in and out, just the internal preamp on, and no preamps at all
Lou, W0FK
St. Louis, MO
"The difference between stupidity and genius is that genius has its limits." Albert Einstein |
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In reply to this post by AC7AC
Ron D'Eau Claire wrote:
> >As Wayne's often mentioned here, the advanced up-conversion design of >the K3 is superior for HF but makes incorporating VHF a real challenge. No challenge at all... had it been thought about at the design stage. Since the K3 is top-of-the-line in so many other respects, it rankles that the 6m sensitivity is poorer than that of many 'inferior' transceivers. Even my old IC746 has a built-in alternative preamp for 6m which makes it easily capable of hearing antenna noise, which my K3 cannot (and yes, it does meet the published sensitivity specification). Phil just discovered something very similar with his old FT100. I'm not shouting or getting angry, but do remain quietly insistent that the inferior 6m sensitivity is a blemish on the K3's otherwise excellent performance. With great respect, it doesn't matter whether 6m is a minority interest or not; this is about excellence and what's needed to achieve it. All the K3 does need for 6m is an alternative preamp with slightly more gain and a lower noise figure than the existing preamp (which was optimized mainly for strong signal handling). That's all it takes to shift the K3's window of dynamic range downward by several dB, which will make it capable of hearing antenna noise on 50MHz at a quiet site; which presently it isn't [1]. Although a preamp can improve the sensitivity by a few dB, the penalty is that a greater number of decibels must always be lost at the strong-signal end of the dynamic range. However, the K3 is better placed than any other transceiver to trade off a little of its dynamic range for a marked improvement in weak-signal performance. The PR6 and many alternative preamps have proved those points. But the point that many people are making is that an adequate 6m preamp did not *have* to be an external accessory. Much of the size and complexity of the PR6 is due to its being an external unit. With forethought, something similar but *much* smaller and simpler could have been designed as an integral part of the KXV3 assembly - there's plenty of space in there. A selectable internal preamp is still possible as a modification involving a few track cuts (watch this space). All the above can be expressed in more technical detail, in terms of antenna noise temperatures and signal/noise ratio on weak signals, but that's the Sunday evening version... oops, Monday morning. [1] if anyone can distinctly hear 6m antenna noise on a bare K3, yours is not a "quiet" site. If you can't hear antenna noise but still claim to be able to hear "all the weak signals"... are you sure you've heard them *all*? -- 73 from Ian GM3SEK Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek _______________________________________________ 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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Ian,
Much forethought was put into this (at the design stage). We knew ahead of time that the 6-m MDS was going to be in the -135 dBm range with the internal preamp, due to the losses in the T-R switching and narrow band-pass filtering. Both were required for this design. A separate 6-m preamp would only have boosted 6-m MDS by a couple of dB because it follows the other front-end losses. Thus we elected -- from the start -- to provide for an *external* 6-m preamp, patched between RX ANT IN/OUT. With this solution, we get a world-class 6-m MDS in the -144 dBm range, and you don't pay for it unless you need it. Every rig has tradeoffs. This was one of ours. 73, Wayne N6KR Ian White GM3SEK wrote: >> As Wayne's often mentioned here, the advanced up-conversion design of >> the K3 is superior for HF but makes incorporating VHF a real >> challenge. > > No challenge at all... had it been thought about at the design stage. --- 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 AC7AC
Elecraft K3 is sold as a "High Performance Radio",
this is in print clearly stated on the web page. The 6m RX in K3 can not be called high performance. With a NF of above 10 and MDS as it is. The transmitter on SSB has so poor IMD that it can not be called high performance. ARRL and many others has measured poor TX IMD. I hear K3´s on the air every day with poor SSB TX IMD. People do have problems with PSK and other digital modes due to poor TX performance. IMO 6m is fixed with the preamp, no big issue anymore. However it should be stated in advertisement that for high performance on 6m K3 needs a preamp. Then we have the transmitter, what to do?? The problem has been swept under the carpet and it doesn´t go away by itself, it is stil there, under the carpet. 73 Jim SM2EKM ---------------------- Ron D'Eau Claire wrote: > I can't speak for the engineering or product decisions that went into > offering 6 meters with the K3, but for an excellent low-noise 6 meter > capability Elecraft does offer the XV50 transverter which is well integrated > into the K3 and K2 rigs offering direct frequency readout, all of the > capabilities of the base K3 (or K2), and the 6 meter band becomes part of > the band selection just like the HF bands. > > The XV144, 222 and 432 round out the same capability, letting you cycle > through bands using the K2 or K3 bandswitch from 160 through 70 cm with one > rig, and each of the VHF/UHF transverters has a low-noise high-performance > receive front end designed specifically for that band. > > As Wayne's often mentioned here, the advanced up-conversion design of the K3 > is superior for HF but makes incorporating VHF a real challenge. Using an XV > transverter specifically designed for each VHF band keeps the K3 (or K2) > operating as a tunable I.F. in the HF (28 MHz) range. > > Ron AC7AC > > > > -----Original Message----- > > On Sun, 25 Jan 2009 12:34:03 -0500 > "Phil LaMarche" <[hidden email]> wrote: >> I purchased a used FT 100 just to monitor 6 while using the other bands > with >> the K3. Today there is a great opening. Signals are screaming from the > FT >> 100 and hardly heard on the K3 using an antenna switch. Guess I better > get >> a Preamp in line quickly. >> >> Phil >> >> >> Philip LaMarche >> LaMarche Enterprises, Inc. >> <http://www.instantgourmetspices.com/> www.instantgourmetspices.com >> >> www.w9dvm.com <http://www.w9dvm.com/> >> 800-395-7795 pin 02 >> 727-944-3226 >> FAX 727-937-8834 >> NASFT 30210 >> W9DVM > **************************************************************************** > ***** > > Phil, > > You're right about the 6mtr. band being practically deaf in the K3!!! I did > order the 6m. preamp > because of > that short-coming! But you would have thought that the BOYZ @ Elecraft > would'nt have short-changed > 6m sensitivity as ALL THE OTHER BANDS HEAR WELL!!! > > Why build a quality rig if one-band is only added as a "after-thought"??? > > Jim/nn6ee > S/N 2406 > > > _______________________________________________ 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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Hi Jan,
I don't think the K3/100's -29 dB for TX IMD is all that far out of line with today's 100 watt class rig. In fact most 100 watt 13.8 volt rigs are a dB or two from this. I think the K3 QRP rig wasn't this good on bands above 17m @ higher power, but still measured -27 dB. Although it would be nice to have it much better (mid 30s or even in the 40s), even my Icom 7700 is was only measured @ -28dB with MRF150 final with 48 volts on them. Seems very rare for a current rig to be in the high -30s and -40s. So I am not sure what the bench mark would be on TX IMD these days or if we could afford it? Question, can you hear IMD off the air or just the artifacts? As Wayne said earlier everything is a trade off. 73 de jay/w5jay.. ----- Original Message ----- From: "Jan Erik Holm" <[hidden email]> Cc: <[hidden email]> Sent: Sunday, January 25, 2009 11:53 PM Subject: [Elecraft] 6 Meters and TX IMD Elecraft K3 is sold as a "High Performance Radio", this is in print clearly stated on the web page. The 6m RX in K3 can not be called high performance. With a NF of above 10 and MDS as it is. The transmitter on SSB has so poor IMD that it can not be called high performance. ARRL and many others has measured poor TX IMD. I hear K3´s on the air every day with poor SSB TX IMD. People do have problems with PSK and other digital modes due to poor TX performance. IMO 6m is fixed with the preamp, no big issue anymore. However it should be stated in advertisement that for high performance on 6m K3 needs a preamp. Then we have the transmitter, what to do?? The problem has been swept under the carpet and it doesn´t go away by itself, it is stil there, under the carpet. 73 Jim SM2EKM ---------------------- Ron D'Eau Claire wrote: > I can't speak for the engineering or product decisions that went into > offering 6 meters with the K3, but for an excellent low-noise 6 meter > capability Elecraft does offer the XV50 transverter which is well > integrated > into the K3 and K2 rigs offering direct frequency readout, all of the > capabilities of the base K3 (or K2), and the 6 meter band becomes part of > the band selection just like the HF bands. > > The XV144, 222 and 432 round out the same capability, letting you cycle > through bands using the K2 or K3 bandswitch from 160 through 70 cm with > one > rig, and each of the VHF/UHF transverters has a low-noise high-performance > receive front end designed specifically for that band. > > As Wayne's often mentioned here, the advanced up-conversion design of the > K3 > is superior for HF but makes incorporating VHF a real challenge. Using an > XV > transverter specifically designed for each VHF band keeps the K3 (or K2) > operating as a tunable I.F. in the HF (28 MHz) range. > > Ron AC7AC > > > > -----Original Message----- > > On Sun, 25 Jan 2009 12:34:03 -0500 > "Phil LaMarche" <[hidden email]> wrote: >> I purchased a used FT 100 just to monitor 6 while using the other bands > with >> the K3. Today there is a great opening. Signals are screaming from the > FT >> 100 and hardly heard on the K3 using an antenna switch. Guess I better > get >> a Preamp in line quickly. >> >> Phil >> >> >> Philip LaMarche >> LaMarche Enterprises, Inc. >> <http://www.instantgourmetspices.com/> www.instantgourmetspices.com >> >> www.w9dvm.com <http://www.w9dvm.com/> >> 800-395-7795 pin 02 >> 727-944-3226 >> FAX 727-937-8834 >> NASFT 30210 >> W9DVM > **************************************************************************** > ***** > > Phil, > > You're right about the 6mtr. band being practically deaf in the K3!!! I > did > order the 6m. preamp > because of > that short-coming! But you would have thought that the BOYZ @ Elecraft > would'nt have short-changed > 6m sensitivity as ALL THE OTHER BANDS HEAR WELL!!! > > Why build a quality rig if one-band is only added as a "after-thought"??? > > Jim/nn6ee > S/N 2406 > > > _______________________________________________ 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 AC7AC
Ron D'Eau Claire wrote:
> > As Wayne's often mentioned here, the advanced up-conversion design of the K3 The K3 is not an up-conversion design. With the exception that the second IF is digital and rather low, it is more like the double conversion amateur bands superhets that preceded the big commercial move to up-conversion. One other thing. I'm not clear whether people are really complaining about sensitivity, or whether they are actually complaining about gain. Sensitivity is about signal being louder than noise. Gain is about both signal and noise being loud. -- David Woolley "The Elecraft list is a forum for the discussion of topics related to Elecraft products and more general topics related ham radio" List Guidelines <http://www.elecraft.com/elecraft_list_guidelines.htm> _______________________________________________ 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 Jay Bromley
I did change subject to TX IMD only.
People has measured down to -24 dB. As I recall ARRL first had a lower figure but "somehow" it got revised. My own measurements show that it´s not usable above 100W. I would keep it at 80W or lower, something seems to happen above 80W. No artifacts, I can hear IMD on the air and also others can. This is the story. At an early stage I heard a friend down in Belgium and I got puzzled since he seemed so wide, lots of trash outside his passband. Then when a friend in Sweden got his K3 we did some testing and the picture was the same. After this I have heard others and it´s following suit. Then, first time I use my K3 on 20m SSB I started to get "splatter reports", also get an email from a friend telling me I had a lot of trash outside my passband due to poor TX IMD, at that point I ran K3 at 120W. As you say, it´s getting rare these days with radios in the -30 to -40 dB bracket. And we are just going to be content with it? No not IMO. Listen on the bands, the situation has become terrible and it´s the same on CW where we have key clix all over the place. Even the K3 has key clix, 5 ms rise/fall time is not enough, I wish it could be set to higher figure. Anyway I will rest my case. I have written about this before and I can clearly see that Elecraft ain´t interested so why should I waist my time. 73 Jim SM2EKM --------------------------------- Jay Bromley wrote: > Hi Jan, > I don't think the K3/100's -29 dB for TX IMD is all that far out of line > with today's 100 watt class rig. In fact most 100 watt 13.8 volt rigs are a > dB or two from this. I think the K3 QRP rig wasn't this good on bands above > 17m @ higher power, but still measured -27 dB. Although it would be nice to > have it much better (mid 30s or even in the 40s), even my Icom 7700 is was > only measured @ -28dB with MRF150 final with 48 volts on them. Seems very > rare for a current rig to be in the high -30s and -40s. > > So I am not sure what the bench mark would be on TX IMD these days or if we > could afford it? > > Question, can you hear IMD off the air or just the artifacts? > > As Wayne said earlier everything is a trade off. > > 73 de jay/w5jay.. > > > ----- Original Message ----- > From: "Jan Erik Holm" <[hidden email]> > Cc: <[hidden email]> > Sent: Sunday, January 25, 2009 11:53 PM > Subject: [Elecraft] 6 Meters and TX IMD > > > Elecraft K3 is sold as a "High Performance Radio", > this is in print clearly stated on the web page. > > The 6m RX in K3 can not be called high performance. > With a NF of above 10 and MDS as it is. > > The transmitter on SSB has so poor IMD that it can > not be called high performance. ARRL and many others > has measured poor TX IMD. I hear K3´s on the air > every day with poor SSB TX IMD. People do have > problems with PSK and other digital modes due to > poor TX performance. > > IMO 6m is fixed with the preamp, no big issue anymore. > However it should be stated in advertisement that for > high performance on 6m K3 needs a preamp. > > Then we have the transmitter, what to do?? The problem > has been swept under the carpet and it doesn´t go > away by itself, it is stil there, under the carpet. > > 73 Jim SM2EKM > ---------------------- > Ron D'Eau Claire wrote: >> I can't speak for the engineering or product decisions that went into >> offering 6 meters with the K3, but for an excellent low-noise 6 meter >> capability Elecraft does offer the XV50 transverter which is well >> integrated >> into the K3 and K2 rigs offering direct frequency readout, all of the >> capabilities of the base K3 (or K2), and the 6 meter band becomes part of >> the band selection just like the HF bands. >> >> The XV144, 222 and 432 round out the same capability, letting you cycle >> through bands using the K2 or K3 bandswitch from 160 through 70 cm with >> one >> rig, and each of the VHF/UHF transverters has a low-noise high-performance >> receive front end designed specifically for that band. >> >> As Wayne's often mentioned here, the advanced up-conversion design of the >> K3 >> is superior for HF but makes incorporating VHF a real challenge. Using an >> XV >> transverter specifically designed for each VHF band keeps the K3 (or K2) >> operating as a tunable I.F. in the HF (28 MHz) range. >> >> Ron AC7AC >> >> >> >> -----Original Message----- >> >> On Sun, 25 Jan 2009 12:34:03 -0500 >> "Phil LaMarche" <[hidden email]> wrote: >>> I purchased a used FT 100 just to monitor 6 while using the other bands >> with >>> the K3. Today there is a great opening. Signals are screaming from the >> FT >>> 100 and hardly heard on the K3 using an antenna switch. Guess I better >> get >>> a Preamp in line quickly. >>> >>> Phil >>> >>> >>> Philip LaMarche >>> LaMarche Enterprises, Inc. >>> <http://www.instantgourmetspices.com/> www.instantgourmetspices.com >>> >>> www.w9dvm.com <http://www.w9dvm.com/> >>> 800-395-7795 pin 02 >>> 727-944-3226 >>> FAX 727-937-8834 >>> NASFT 30210 >>> W9DVM >> **************************************************************************** >> ***** >> >> Phil, >> >> You're right about the 6mtr. band being practically deaf in the K3!!! I >> did >> order the 6m. preamp >> because of >> that short-coming! But you would have thought that the BOYZ @ Elecraft >> would'nt have short-changed >> 6m sensitivity as ALL THE OTHER BANDS HEAR WELL!!! >> >> Why build a quality rig if one-band is only added as a "after-thought"??? >> >> Jim/nn6ee >> S/N 2406 >> >> >> > > > _______________________________________________ > 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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Jan Erik Holm wrote:
> Anyway I will rest my case. I have written about this before > and I can clearly see that Elecraft ain´t interested so > why should I waist my time. > > 73 Jim SM2EKM > You obviously are not happy with the rig. My K3 works fine. The IMD gets a bit worse over 100W but then Elecraft do state not to run SSB over 100W. I suggest if you are so annoyed with it that you simply sell the rig and buy something else. 73 Ian -- Ian J Maude, G0VGS SysOp GB7MBC DX Cluster Member RSGB, GQRP, FISTS K2 #4044 |K3 #455 http://www.amateurradiotraining.org _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Jan Erik Holm
Jan Erik Holm wrote on Monday, January 26, 2009 8:52 AM
As you say, it´s getting rare these days with radios in the -30 to -40 dB bracket. And we are just going to be content with it? No not IMO. Jan, I agree in the context of Amateur Service radios. The time might come perhaps sooner than later when it does not matter whether or not we amateurs are content to put up with poor Tx IMD performance, somebody else might set the limits for us if we do not. Although the Amateur Service has been allowed for decades to police itself, there is growing pressure from some users who have been assigned allocations adjacent to our bands to clean up what could be called "outside band edge whiskers" created by amateurs, be they key clicks or IMD products or other types of garbage. Forty years ago in Canada the Type Approval specs for low power HF transmitters for use in commercial services set the limit for Tx IMD at 30db below each tone in a two tone test at full rated PEP output. Input to mic connector, also to any other audio input interface. I must own up to being involved in writing those specs. However today such a limit does not reflect what is required by responsible spectrum management nor does it reflect what can be ahcieved in practice at reasonable cost. We need to look for much better performance than 30db below test tone. FWIW 73, Geoff GM4ESD _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Is there a "sweet spot" to which one can adjust the power output for minimum IMD, if so, how would you do it easily? I presume you would need another rx or spectrum analyser. And I bet it changes with antenna reflections, ie from one end of the band to the other.
I dare say a lot of K3s are followed by linears which add even more IMD, so, it might be tricky to optimise for the station as a whole and not just at minimum drive from the K3; perhaps a power pad is needed, but who would bother ? It is hoped that the Elecraft linear might take this into account. David G3UNA ---- Geoffrey Mackenzie-Kennedy <[hidden email]> wrote: > Jan Erik Holm wrote on Monday, January 26, 2009 8:52 AM > > As you say, it´s getting rare these days with radios in the > -30 to -40 dB bracket. And we are just going to be content > with it? No not IMO. > > Jan, > > I agree in the context of Amateur Service radios. > > The time might come perhaps sooner than later when it does not matter > whether or not we amateurs are content to put up with poor Tx IMD > performance, somebody else might set the limits for us if we do not. > Although the Amateur Service has been allowed for decades to police itself, > there is growing pressure from some users who have been assigned allocations > adjacent to our bands to clean up what could be called "outside band edge > whiskers" created by amateurs, be they key clicks or IMD products or other > types of garbage. > > Forty years ago in Canada the Type Approval specs for low power HF > transmitters for use in commercial services set the limit for Tx IMD at 30db > below each tone in a two tone test at full rated PEP output. Input to mic > connector, also to any other audio input interface. I must own up to being > involved in writing those specs. However today such a limit does not reflect > what is required by responsible spectrum management nor does it reflect what > can be ahcieved in practice at reasonable cost. We need to look for much > better performance than 30db below test tone. > > FWIW > > 73, > Geoff > GM4ESD > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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TX IMD just goes on getting worse as you increase the power. It starts getting worse much more quickly as you approach and then exceed the maximum rated power. So your "sweet spot" would be "as little power as possible." :) The issue with the K3 is that the transmitter does not seem to be as clean as is possible with the "state of the sart", even given the restrictions imposed by having a 13.8VDC supply. I am only able to make PSK31 IMD measurements which are not directly comparable with two tone measurements usually used for SSB transmitters, but I assume that they both reflect upon the TX amplifier linearity, or lack of it. My K3 goes from -30dB at 2W to -22dB at 12W. My K2 goes from -29dB at 2W to -27dB at 14W (both measured on 30m). Therefore it seems to me that my K2 has a cleaner transmitter (at least as far as IMD goes) than my K3, which I find surprising since the K2 was built my me nearly 10 years ago using only the barest minimum of test equipment, whereas the K3 low power PA module was aligned and tested by Elecraft with a lab full of equipment. It seems to be the way on this reflector that anyone who makes any criticism of anything Elecraft makes comes in for a lot of abuse and ridicule. But I wonder whether those who claim the TX IMD of the K3 is poor actually have a valid point, but their K3s are just not as well set up as those belonging to people who don't see anything wrong with them? It seems unlikely to me that Elecraft would deliberately choose a worse design of PA for the K3 than that used successfully for years in the K2. Yet the figures I just gave seem to suggest that considerably better performance is possible. Obviously, my test results are for the QRP version. But if the signal going in to the 10W PA is not as good as it could be, the output is certainly not going to be any better.
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 Jan Erik Holm
Not doubting your TX IMD report in PSK. But I typically see ~-32dB IMD when
checking PSK at 50W. ------------------------- 73, Greg - AB7R Whidbey Island WA NA-065 On Mon Jan 26 7:58 , "Julian, G4ILO" sent: > > > >David Cutter wrote: >> >> Is there a "sweet spot" to which one can adjust the power output for >> minimum IMD, if so, how would you do it easily? I presume you would need >> another rx or spectrum analyser. And I bet it changes with antenna >> reflections, ie from one end of the band to the other. >> >> I dare say a lot of K3s are followed by linears which add even more IMD, >> so, it might be tricky to optimise for the station as a whole and not just >> at minimum drive from the K3; perhaps a power pad is needed, but who would >> bother ? >> >> It is hoped that the Elecraft linear might take this into account. >> >> > > >TX IMD just goes on getting worse as you increase the power. It starts >getting worse much more quickly as you approach and then exceed the maximum >rated power. So your "sweet spot" would be "as little power as possible." :) > >The issue with the K3 is that the transmitter does not seem to be as clean >as is possible with the "state of the sart", even given the restrictions >imposed by having a 13.8VDC supply. I am only able to make PSK31 IMD >measurements which are not directly comparable with two tone measurements >usually used for SSB transmitters, but I assume that they both reflect upon >the TX amplifier linearity, or lack of it. > >My K3 goes from -30dB at 2W to -22dB at 12W. > >My K2 goes from -29dB at 2W to -27dB at 14W (both measured on 30m). > >Therefore it seems to me that my K2 has a cleaner transmitter (at least as >far as IMD goes) than my K3, which I find surprising since the K2 was built >my me nearly 10 years ago using only the barest minimum of test equipment, >whereas the K3 low power PA module was aligned and tested by Elecraft with a >lab full of equipment. > >It seems to be the way on this reflector that anyone who makes any criticism >of anything Elecraft makes comes in for a lot of abuse and ridicule. But I >wonder whether those who claim the TX IMD of the K3 is poor actually have a >valid point, but their K3s are just not as well set up as those belonging to >people who don't see anything wrong with them? > >It seems unlikely to me that Elecraft would deliberately choose a worse >design of PA for the K3 than that used successfully for years in the K2. Yet >the figures I just gave seem to suggest that considerably better performance >is possible. Obviously, my test results are for the QRP version. But if the >signal going in to the 10W PA is not as good as it could be, the output is >certainly not going to be any better. > >----- >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/6-Meters-tp2213777p2218679.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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In reply to this post by Julian, G4ILO
There is something that has been puzzling me for the last 17
years. In November of 1991, QST reviewed the Yaesu FT-990, which used a 13.8 vdc PA. Worst case measured 3rd order IMD was -38 dB, 5th order was -47 dB. This measurement was at 100 watts output. The review is available on ARRL's members-only web site. ARRL had this comment, "It's refreshing to see that it's possible to make a 100-W MF/HF radio with low voltage finals AND such low-distortion transmitter performance". As far as I know, no ham 13.8 volt radio has even come close to this TX IMD performance ever since. Looking at the 990 PA, there's a 2sc2166 predriver, a pair of 2sc3133 drivers, and a pair of 2sc2879 finals, all npn transistors, nothing exotic. So what was Yaesu's secret, and why hasn't anyone else even come close? Dave Hachadorian, K6LL Yuma, AZ . _______________________________________________ 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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