K3 #441 received
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From my posting from last week:
- Ordered (with 50% deposit) 6 June 2007 with subsequent modifications. - Received and responded to "Lisagram" late Tuesday, 12 Feb 2008. - Called by Madeline for final payment info on Thursday, 14 Feb. - Received UPS shipping notice late that same day. Scheduled delivery is 19 Feb. Update: - Received K3/100 kit today (Tuesday, 19 Feb) as promised. Now I have a big decision to make. Should I drive up to Boulder from Denver to see Rob Sherwood's talk or stay home and assemble my new toy? Other alternatives that I've considered that would give Rob another K3 sample to test: - Assemble it when I get back home around midnight. No - I really need my beauty sleep and generally function badly when I'm tired. - Let Rob assemble and align it himself. No - someone will say he's too expert and that would bias the results. - Assemble it later when my workload permits. But I might be "disqualified" for being an electronics engineer and firmware developer who might tweak the performance in Elecraft's favor. - Have my daughter, an art historian, assemble and align it. Oops, can't do that - she's living in France. Oh my, what to do? Gus Hansen KB0YH _______________________________________________ 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 a message dated 2/19/2008 3:17:50 P.M. Pacific Standard Time,
[hidden email] writes: >From my posting from last week: - Ordered (with 50% deposit) 6 June 2007 with subsequent modifications. - Received and responded to "Lisagram" late Tuesday, 12 Feb 2008. - Called by Madeline for final payment info on Thursday, 14 Feb. - Received UPS shipping notice late that same day. Scheduled delivery is 19 Feb. Update: - Received K3/100 kit today (Tuesday, 19 Feb) as promised. Now I have a big decision to make. Should I drive up to Boulder from Denver to see Rob Sherwood's talk or stay home and assemble my new toy? Other alternatives that I've considered that would give Rob another K3 sample to test: - Assemble it when I get back home around midnight. No - I really need my beauty sleep and generally function badly when I'm tired. - Let Rob assemble and align it himself. No - someone will say he's too expert and that would bias the results. - Assemble it later when my workload permits. But I might be "disqualified" for being an electronics engineer and firmware developer who might tweak the performance in Elecraft's favor. - Have my daughter, an art historian, assemble and align it. Oops, can't do that - she's living in France. Oh my, what to do? Gus Hansen KB0YH _______________________________________________ Align a K3 ???? Al WA6VNN **************Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/ 2050827?NCID=aolcmp00300000002598) _______________________________________________ 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 Augie "Gus" Hansen
Go to Rob's talk and make a video for the rest of us to enjoy and learn.
Have someone else drive while you sit in the back seat doing the assembly ; o ) David G3UNA snip > Now I have a big decision to make. Should I drive up to Boulder from > Denver to see Rob Sherwood's talk or stay home and assemble my new toy? > > > Oh my, what to do? > > Gus Hansen > KB0YH > _______________________________________________ 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 David,
> Go to Rob's talk and make a video for the rest of us to enjoy and > learn. Have someone else drive while you sit in the back seat doing > the assembly ; o ) I chose to attend the Boulder Amateur Radio Club (BARC) meeting. Couldn't get a chauffeur so had to postpone the assembly, probably until this weekend. Following the basic club meeting and discussion, Rob's presentation and the interleaved Q&A took about two hours and was an evening well spent. BARC is in the process of setting up new clubhouse facilities at the Boulder County Airport, where this meeting took place. Unfortunately no taping was done. However, much of the content was merged from the Dayton presentations that Rob makes available on his web site: http://www.sherweng.com/ Regarding receiver performance, Rob emphasized the importance of good narrow-spaced dynamic range, correct AGC behavior in the presence of impulse noise, and low local oscillator phase noise. Good narrow-spaced dynamic range is particularly important for CW contesters, less so for phone operators. The K3 is the first rig he has tested that exceeds 100 dB for close-in (2 kHz) spacing dynamic range. In addition, Rob spent some time talking about the sad state of transmit IMD in virtually all modern transmitters, except perhaps those that provide Class A operation. Splatter on SSB transmissions, especially with solid state PAs, is usually due to aggressive use of ALC to control power. And key clicks on CW transmissions usually result from ALC and rise/fall time issues. Gus Hansen KB0YH K2 S/N 3302 K3 S/N 441 _______________________________________________ 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 |
Class - A operatiom (was K3 #441 received)
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Augie's report on on Mr. Sherwood's remarks were quite interesting. The last remark concerning poor transmit specifications interested me.
>From my days in Vo-Tech Electronics in High School some 40 years ago....isn't Class A not very efficient? You can get more power out of class AB1 or AB2 but you have to keep to the linear portion of the curve to avoid distortion. I guess what is happening is that the rigs are not keeping to the linear portion of the curve because of over drive by the operator or by the circuitry to compensate for something or other. A linear amp has to operated in the linear part of the curve. Right? So, what are these rigs doing? If I remember correctly, isn't Yaesu's FT9000 or FT1000XXX has a button that allows Class-A operation? What rigs run Class A? How does that sound on the RX end and what do you give up on the TX end? Power out? Interesting discussion with Mr. Sherwood's Data and comments. Lee - K0WA In our day and age it seems that Common Sense is in short supply. If you don't have any Common Sense - get some Common Sense and use it. If you can't find any Common Sense, ask for help from somebody who has some Common Sense. Is Common Sense divine? _______________________________________________ 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 Wed, 20 Feb 2008 08:28:13 -0800 (PST), Lee Butler wrote:
>Augie's report on on Mr. Sherwood's remarks were quite interesting. The last remark concerning poor transmit specifications interested me. > >>From my days in Vo-Tech Electronics in High School some 40 years ago....isn't Class A not very efficient? You can get more power out of class AB1 or AB2 but you have to keep to the linear portion of the curve to avoid distortion. I guess what is happening is that the rigs are not keeping to the linear portion of the curve because of over drive by the operator or by the circuitry to compensate for something or other. A linear amp has to operated in the linear part of the curve. Right? So, what are these rigs doing? > >If I remember correctly, isn't Yaesu's FT9000 or FT1000XXX has a button that allows Class-A operation? The FT-1000MP rigs have Class A capability. I always excited my Alpha 87A in that setting in both CW and SSB. I think the newer high end Yaesu rigs have it too. > >What rigs run Class A? > >How does that sound on the RX end and what do you give up on the TX end? Power out? > >Interesting discussion with Mr. Sherwood's Data and comments. > >Lee - K0WA > > > >In our day and age it seems that Common Sense is in short supply. If you don't have any Common Sense - get some Common Sense and use it. If you can't find any Common Sense, ask for help from somebody who has some Common Sense. Is Common Sense divine? >_______________________________________________ >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 "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." --Benjamin Franklin 1775 Support the entire Constitution, not just the parts you like. http://www.n5ge.com http://www.eQSL.cc/Member.cfm?N5GE _______________________________________________ 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
Amateur Radio Operator N5GE
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In reply to this post by k0wa@swbell.net
I was in attendance at Rob Sherwood's talk last night also. It was quite
good and very informative. It was not videotaped. Would have been tough to format it for U-tube, as was 2 hours with lots of audience interaction. Having succeeded at least partially in getting more meaningful CW receive measurements accepted (Close-in 2 KHz dynamic range), Rob's next focus indeed seems to be reducing transmitted IMD from today's (more likely tomorrow's) rigs. This will be a design issue rather than a measurement issue. The class A rigs are definitely superior (by 10 to 20 db if I remember his data correctly) in this regard, but of course there are the very consequential power dissipation and efficiency issues which may discourage their use by most operators. Question is, can better transmit IMD performance be achieved with careful design of class AB amplifiers? Rob said that he had not yet measured the transmit IMD of the K3 but plans to do so in the next week or two. Should be interesting. 73 ... Craig AC0DS _______________________________________________ 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 Augie "Gus" Hansen
Is there a radio club in the Boulder area then? I am visiting this summer. Depending on timing, I may have a K3 and it would be great to visit.
Mike
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AD6XY - Mike wrote:
> Is there a radio club in the Boulder area then? I am visiting this summer. > Depending on timing, I may have a K3 and it would be great to visit. Yes, a very active one at that. Check out the the BARC web site: http://www.qsl.net/w0dk/ They also run a BARC Jrs. youth program, which does a great job of getting youngsters interested and participating in ham radio. Gus Hansen KB0YH _______________________________________________ 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 k0wa@swbell.net
In a message dated 2/20/08 11:29:20 AM Eastern Standard Time, [hidden email]
writes: > isn't Class A not very efficient? That depends on how you define efficiency. First off, an ideal Class A amplifier that is not overdriven and is dealing only with symmetrical waveforms draws the same DC power regardless of signal level. That means its efficiency goes up and down with signal level. Also means that the amp must be capable of dissipating the full DC input with no signal, or at low signal levels. At full power, when amplifying sine waves, an ideal Class A amplifier can deliver 50% efficiency. IOW, on CW or FM/FSK, an ideal Class A amp can deliver 1 watt of RF for every 2 watts of DC. So even at full power and ideal conditions, a Class A amplifier dealing with sine waves has to dissipate half the DC input. Of course in the real world you don't get ideal efficiency. 35-40% overall is very good - I don't know if manufactured rigs are that good. You can get more power out of class AB1 or AB2 but you have to keep to the > linear portion of the curve to avoid distortion. I guess what is happening > is that the rigs are not keeping to the linear portion of the curve because > of over drive by the operator or by the circuitry to compensate for something > or other. A linear amp has to operated in the linear part of the curve. > Right? So, what are these rigs doing? The "linear part of the curve" is pretty limited for real-world devices. Yet to get max power, the whole curve is used. It only takes a little bit of nonlinearity to create distortion products. For example, suppose an amplifier with 100W output has enough nonlinearity to produce a distortion product that is 1 watt. Such an amp's distortion is only 20dB down. To reach 40 dB down, (.01%) the distortion product would have to be only 10 milliwatts. 73 de Jim, N2EY ************** Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/ 2050827?NCID=aolcmp00300000002598) _______________________________________________ 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 |
Re: Class - A operatiom (was K3 #441 received)
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Jim <[hidden email]> wrote on Thursday, February 21, 2008 at 2:03 AM:
> It only takes a little bit of nonlinearity to create distortion products. For > example, suppose an amplifier with 100W output has enough nonlinearity to > produce a distortion product that is 1 watt. Such an amp's distortion is > only > 20dB down. To reach 40 dB down, (.01%) the distortion product would have > to be > only 10 milliwatts. Not to be forgotten are the distortion products generated by the exciter. A perfect distortion free linear amplifier driven by an exciter whose IMD products are only 30db down will produce an output with products down 30db approximately. A case of 'garbage in - garbage out'. 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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