Re: [Elecraft] KPA-200
Steve Ward writes: Seems to me the biggest issue would be (DC) power. Most of the rigs that can do 200w internally seem to come with their own custom power supplies that give 24 or 48 VDC. Running 200w on 13.8VDC requires a LOT of amperes and is probably not practical. I believe you are right Steve. It was a whimsical idea. It makes no sense to think inside the box (pun.) 73, Fred, AE6IC, K3#2241 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
Dave, I performed similar tests using a Marconi signal generator in the following test configurations: 1) static benchmark test: generator directly coupled to 144Mhz receiver 2) live on the air tests: smal antenne coupled to generator, receiver uses outdoor 144Mhz antenna. Test was performed with outdoor antenna aimed at a quiet direction. My results between hearing the weak signal in the noise yes/no: static benchmark setup: 1.8 dB Live on the air setup: 2.2-2.5 dB Same happens when I insert the DCI 4-pole 144 bandfilter, which has 0.8dB insertion loss; never ever heard any difference in copying weak signals. These results and some 15 years of trying various pre amps in many situations, made me decide to forget about this whole pre-amp hype (I never did EME, so cannot decide on that) on VHF. 73 Mark, PA5MW At the noise level, I had to work pretty hard to convince myself that I could hear the difference that one db would make. Two db was noticeable, but just barely. Three db was definitely noticeable and in my opinion could easily make the difference between making a weak signal DX contact or not. 73, Dave AB7E __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
I agree that 200 watts inside the K3 isn't a good idea (heat) but having an external (300-400 watt?) amp that could be driven by 10 watts of input (key point here!) would be sweet! This amp could be used by all the Elecraft rigs, not just the K3. For contests turn it up to the low power limit per the rules. On 30m, run full power and be a big gun. I assume a lower power amp (1/2 KW) would be considerably cheaper to build buy. - Keith N1AS - - K3 711 - -Original Message- From: Fred Atchley Subject: Re: [Elecraft] KPA-200 Actually Gary, KPA-200 sounds like a good idea. I like contesting and prefer low power. The problem is that different contests define low power as 100, 150 or 200 W. It would be nice to optimize low power for any given contest. BTW, I wonder if the KAT3 would also need to be replaced. 73, Fred __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
I'm with you on this one, Keith! I'm a low power CW contester and would surely enjoy using the 150 or 200 W power limit when appropriate instead of accepting the db or so of loss with my 100W K3. I have NO interest in running a KW, however, so high power amps have no appeal here. A small amp with internal power supply with 200W or more capability would be quite interesting. For my purposes it wouldn't even need to be linear. As someone else pointed out, class C, D or E could make for an interesting design! 73 Craig AC0DS __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
We do not see 200W inside the K3 any time soon. The heat, current and other issues make this difficult. 73, Eric WA6HHQ Elecraft List Moderator, among other things :-) _..._ Darwin, Keith wrote: I agree that 200 watts inside the K3 isn't a good idea (heat) but having an external (300-400 watt?) amp that could be driven by 10 watts of input (key point here!) would be sweet! This amp could be used by all the Elecraft rigs, not just the K3. For contests turn it up to the low power limit per the rules. On 30m, run full power and be a big gun. I assume a lower power amp (1/2 KW) would be considerably cheaper to build buy. - Keith N1AS - - K3 711 - -Original Message- From: Fred Atchley Subject: Re: [Elecraft] KPA-200 Actually Gary, KPA-200 sounds like a good idea. I like contesting and prefer low power. The problem is that different contests define low power as 100, 150 or 200 W. It would be nice to optimize low power for any given contest. BTW, I wonder if the KAT3 would also need to be replaced. 73, Fred __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
a external 200-400 watt amp is a fairly trivial design, if you want one order some parts and get building. You could do this with a couple 813's for pretty low cost, or solid state for a bit more money. I'm surprised how many people sit on their rear end and complain about this or that product not existing, and how elecraft should design one for them. Start acting like hams and try rolling your own, you have complete control over the feature set you want then. If you are unwilling to do this, I think you have no business clogging the reflector with your criticisms and wish lists, why not keep the posts on topic to actual elecraft products, their building, and troubleshooting. /end rant. Matt W8ESE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
Eric, the posts on this thread by Gary, Keith and me are positive with regard to Elecraft, so please do not consider them as criticisms in any way. I've been a Ham since 1957 and Elecraft is the best thing to happen since 807's. Thanks for a great reflector. 73, Fred __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
Matt, W8ESE, wrote: a external 200-400 watt amp is a fairly trivial design, if you want one order some parts and get building. You could do this with a couple 813's for pretty low cost, or solid state for a bit more money. --- 813s! I'm with you Matt! I have to constantly remind myself that Ham radio has changed. For some of us, the first and most interesting part of Ham radio is the challenge of building and modifying gear. For others, the most interesting part of Ham radio is snagging new DX or hitting a bigger contest score. Many of these Hams are looking for plug 'n play solutions. They have little or no interest in building. Of course most of us are a little bit of both, but the swing is definitely toward the plug 'n play group here on the Elecraft reflector. We're all Hams, but becoming more disparate in our interests as times change. I sometimes feel like I'm bouncing back and forth across a warp in space-time, reading here about people drooling over a $13,000 legal-limit amplifier or a better feeling knob, then finding in my in-box other e-mails about Hams who are still cobbling their receivers and transmitters together from scrapped 1960's TV sets and building variable condensers out of discarded food cans. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
I like to homebrew some of my equipment, all, if I could produce equipment as good as Elecraft's and some of the other well known vendors. Building an amplifier is one area I believe the ham can come close to building a product as good as the average vendor's. If you are talking about tube amps, I think the ham can do a better job then many of the vendor amps. If you want a fully integrated amp for the K2 and/or K3 that will be a little harder and you might want to wait for Elecraft. Frank - W4NHJ - Original Message - From: Matt Palmer kd8...@gmail.com To: Elecraft@mailman.qth.net Sent: Tuesday, May 19, 2009 10:10 AM Subject: Re: [Elecraft] KPA-200 a external 200-400 watt amp is a fairly trivial design, if you want one order some parts and get building. You could do this with a couple 813's for pretty low cost, or solid state for a bit more money. I'm surprised how many people sit on their rear end and complain about this or that product not existing, and how elecraft should design one for them. Start acting like hams and try rolling your own, you have complete control over the feature set you want then. If you are unwilling to do this, I think you have no business clogging the reflector with your criticisms and wish lists, why not keep the posts on topic to actual elecraft products, their building, and troubleshooting. /end rant. Matt W8ESE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] KPA-200
Snip a external 200-400 watt amp is a fairly trivial design, if you want one order some parts and get building. You could do this with a couple 813's for pretty low cost, or solid state for a bit more money. I'm surprised how many people sit on their rear end and complain about this or that product not existing, and how elecraft should design one for them. Start acting like hams and try rolling your own, you have complete control over the feature set you want then. If you are unwilling to do this, I think you have no business clogging the reflector with your criticisms and wish lists, why not keep the posts on topic to actual elecraft products, their building, and troubleshooting. End snip Oh, I didn't realise I was causing such consternation. After reading the above quoted text I feel as though I don't need to read this type of post in the future. I have better things to do with my time anyway, I certainly do not have to put up with this type of comment. Unsubscribe is just as easy and I can do that without needing to design and build anything so you can continue along with comments in the same vein but I will not be getting them cluttering up my inbox. And to think I thought this was a hobby?...how wrong I have been. Gary Sent via BlackBerry® from Telstra __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
On the contest side, all the CQWW and CQ WPX contests for all three modes (CW, Phone and RTTY) have a 100 watt limit for the Low Power category. So do the NCJ NAQP and Sprint contests, twelve total each year. The reason for this is two-fold. First, 100 watts covers the majority of HF transceivers and second, it is a larger distinction from High Power. If someone wants to run more than 100 watts, they can enter the High Power category. Unfortunately, ARRL still has a 150 watt PEP limit on their Low Power category. However, the effective difference between 100 and 150 watts is negligible in reality and many contesters, including the serious ones, don't worry about running 100 watts in ARRL contests. Ed - W0YK Eric, WA6HHQ replied: We do not see 200W inside the K3 any time soon. The heat, current and other issues make this difficult. Darwin, Keith wrote: I agree that 200 watts inside the K3 isn't a good idea (heat) but having an external (300-400 watt?) amp that could be driven by 10 watts of input (key point here!) would be sweet! This amp could be used by all the Elecraft rigs, not just the K3. For contests turn it up to the low power limit per the rules. On 30m, run full power and be a big gun. I assume a lower power amp (1/2 KW) would be considerably cheaper to build buy. Fred Atchley replied: Actually Gary, KPA-200 sounds like a good idea. I like contesting and prefer low power. The problem is that different contests define low power as 100, 150 or 200 W. It would be nice to optimize low power for any given contest. BTW, I wonder if the KAT3 would also need to be replaced. 73, Fred __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
I worked someone using K2/10 with ALS600 modified for low power (by cutting some input resistors). He said he was getting 400W on most bands. Ignacy I agree that 200 watts inside the K3 isn't a good idea (heat) but having an external (300-400 watt?) amp that could be driven by 10 watts of input (key point here!) would be sweet! -- View this message in context: http://n2.nabble.com/KPA-200-tp2936305p2940559.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
--- Matt, W8ESE, wrote: a external 200-400 watt amp is a fairly trivial design, if you want one order some parts and get building. You could do this with a couple 813's for pretty low cost, or solid state for a bit more money. --- Ron, AC7AC, replied: *snip* For some of us, the first and most interesting part of Ham radio is the challenge of building and modifying gear. For others, the most interesting part of Ham radio is snagging new DX or hitting a bigger contest score. Many of these Hams are looking for plug 'n play solutions. They have little or no interest in building. While Matt has a point, I'm more inclined to hang with Ron. There is significant variation in interests. I've never been that interested in building. I wasn't back in 1977, and am not today. The K2 I build was lots of fun, but I've been there / done that. Yes, I am a ham but that doesn't mean I'm an electronics hobbyist. I'm a CW hobbyist. I like CW, I like sending code with bugs straight keys and the Elecraft gear is my chosen vehicle. I don't operate SSB, FM, Packet, VHF, UHF. Others do. Interests vary. I don't have time to build. I barely have time to be on the air at all. Full time job, part time job, Church duties, volunteering at the school, mowing the grass (2.5 acres) ... You get the idea. And, yes, I absolutely feel that discussing possible future amps and my desires for them is completely on-topic since Elecraft is interested in producing an amp. My views on which Pellet Rifles I prefer or why I use Canon rather than Nikon (http://DarwinPhotoVT.com) would be off topic so I won't post about those. 73! - Keith N1AS - - K3 711 - __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
Absolutely! :-) We always appreciate constructive feedback and suggestions. All that we ask is that people avoid posting on a high # of postings topic unless they have substantive info to add. 73, Eric WA6HHQ Fred Atchley wrote: Eric, the posts on this thread by Gary, Keith and me are positive with regard to Elecraft, so please do not consider them as criticisms in any way. I've been a Ham since 1957 and Elecraft is the best thing to happen since 807's. Thanks for a great reflector. 73, Fred __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
Guys - Personal criticisms are outside of the list guidelines. Please do NOT post emails saying a posting is inappropriate. Sent them to me instead. Please also do not post what a 'real ham' should, or should not be doing. It s a hobby, and all are welcome at all levels of expertise and interest. Wish lists and criticisms of the product are welcomed, as long as they are constructive. That's how we stay on top of what's really needed out there. :-) 73, Eric WA6HHQ Elecraft === rfenab...@gmail.com wrote: Snip a external 200-400 watt amp is a fairly trivial design, if you want one order some parts and get building. You could do this with a couple 813's for pretty low cost, or solid state for a bit more money. I'm surprised how many people sit on their rear end and complain about this or that product not existing, and how elecraft should design one for them. Start acting like hams and try rolling your own, you have complete control over the feature set you want then. If you are unwilling to do this, I think you have no business clogging the reflector with your criticisms and wish lists, why not keep the posts on topic to actual elecraft products, their building, and troubleshooting. End snip Oh, I didn't realise I was causing such consternation. After reading the above quoted text I feel as though I don't need to read this type of post in the future. I have better things to do with my time anyway, I certainly do not have to put up with this type of comment. Unsubscribe is just as easy and I can do that without needing to design and build anything so you can continue along with comments in the same vein but I will not be getting them cluttering up my inbox. And to think I thought this was a hobby?...how wrong I have been. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
On Tue, 19 May 2009 08:30:26 +0200, pa...@home.nl wrote: My results between hearing the weak signal in the noise yes/no: static benchmark setup: 1.8 dB Live on the air setup: 2.2-2.5 dB Several years ago, N6ZFO published some statistical analysis of Sweepstakes score suggesting that a 1 dB increase in transmitted signal strength is good for about a 2.6% increase in an operator's score. More than once, I've unsuccessfrully called a weak station with 800-1,000 watts, then pushed the amp up to legal power and worked him. It depends on QRM and QRN on the other end, and sometimes whether his RX antenna is pointed in your direction. I work a lot of stations that I wouldn't have heard without my Beverages. And lots of guys are stuck with S8 noise levels. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
I suppose 813's are still available, but I don't see them listed very often. I do, however, see 811's a lot. Wouldn't a couple of those work for that kind of power range? Maybe it would take 3, but they seem to be readily available, and pretty inexpensive. By the way, at the swap area at Dayton this year I saw an old Heath HA-14 (hadn't seen one of those for a while!). I think it uses 811's or 572B's--a pair--laying sideways. The guy was pretty proud of it though, as he wanted $900 for it! I guess they are rare enough that he was serious. Dave W7AQK - Original Message - From: Ron D'Eau Claire r...@cobi.biz To: Elecraft@mailman.qth.net Sent: Tuesday, May 19, 2009 7:52 AM Subject: Re: [Elecraft] KPA-200 Matt, W8ESE, wrote: a external 200-400 watt amp is a fairly trivial design, if you want one order some parts and get building. You could do this with a couple 813's for pretty low cost, or solid state for a bit more money. --- 813s! I'm with you Matt! I have to constantly remind myself that Ham radio has changed. For some of us, the first and most interesting part of Ham radio is the challenge of building and modifying gear. For others, the most interesting part of Ham radio is snagging new DX or hitting a bigger contest score. Many of these Hams are looking for plug 'n play solutions. They have little or no interest in building. Of course most of us are a little bit of both, but the swing is definitely toward the plug 'n play group here on the Elecraft reflector. We're all Hams, but becoming more disparate in our interests as times change. I sometimes feel like I'm bouncing back and forth across a warp in space-time, reading here about people drooling over a $13,000 legal-limit amplifier or a better feeling knob, then finding in my in-box other e-mails about Hams who are still cobbling their receivers and transmitters together from scrapped 1960's TV sets and building variable condensers out of discarded food cans. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
Fred Atchley writes: Actually Gary, KPA-200 sounds like a good idea. I like contesting and prefer low power. The problem is that different contests define low power as 100, 150 or 200 W. It would be nice to optimize low power for any given contest. BTW, I wonder if the KAT3 would also need to be replaced. 73, Fred Seems to me the biggest issue would be (DC) power. Most of the rigs that can do 200w internally seem to come with their own custom power supplies that give 24 or 48 VDC. Running 200w on 13.8VDC requires a LOT of amperes and is probably not practical. 73, Steve AD7OG K3 #1544 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] KPA-200
What would the K3 be like if one could order an optional plug in module to replace the 100W PA with a 200W PA? Just a thought...maybe I didn't get quite enough sleep Gary Sent via BlackBerry® from Telstra __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] KPA-200
Snip That would be good for driving an amp to full power ! Portable operation would be improved given restrictions on battery and solar charging, notwithstanding a few less Llamas to truck around...:-) Gary Sent via BlackBerry® from Telstra __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
-Original Message- What would the K3 be like if one could order an optional plug in module to replace the 100W PA with a 200W PA? Just a thought...maybe I didn't get quite enough sleep Gary - IMX, it would be an undetectable change in signal strength under almost any conditions. Over the years most engineers working in HF radio systems have found that the minimum discernable change in a signal is about 3 dB (2:1 change in power) under ideal conditions. That's 3 times greater than the 'standard' for audio lab work, but what is found in practice given typical background noise, minimal QSB, etc. on an HF signal. You can test this on the air very easily. Just hook up with someone in a normal QSO and then cut your power in half and see if they notice any difference. Don't tell them what you're testing, just that you are making a change, and see if anyone can tell you what you changed. If they're looking at the S-meter on one of those absurd rigs that jumps 1 or 2 S-units for every 2 dB or so of signal change, they'll see something if you're close enough for a rock-solid signal, but they're not likely to hear it. I don't normally get excited about any major change that doesn't give me a 10:1 (10 dB) improvement in power. Now, let's not confuse that with having an efficient station. As any QRP enthusiast (or smart Ham at any power) will tell you, a dB here and a dB there eventually adds to a significant change in signal strength. But the cost/benefits ratio of doubling the power compared to the same ratio going to the legal limit usually makes such a small change a bad investment. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
rfenab...@gmail.com wrote: What would the K3 be like if one could order an optional plug in module to replace the 100W PA with a 200W PA? Just a thought...maybe I didn't get quite enough sleep Gary Sent via BlackBerry® from Telstra __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html I also would love that, Garybut I don't think it is technically possible for them, at least that is what they told me at Dayton previously :-( VY 73, Lance -- Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8) P.O. Box 73 Frenchtown, MT 59834 USA QTH: DN27UB TEL: (406) 626-5728 URL: http://www.bigskyspaces.com/w7gj 2m DXCC #11/6m DXCC #815 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
I think it all depends upon how you operate. About two years ago I put together some audio files to determine how much difference a couple of db would make for readability, as at the time I was trying to decide between a couple of different antenna options. I generated some CW using CW Player, a free text-to-audio application, and then I mixed that with some 80m background noise I had recorded. I varied the relative signal-to-noise level in one db increments relative to to the noise until I got below the noise level. At the noise level, I had to work pretty hard to convince myself that I could hear the difference that one db would make. Two db was noticeable, but just barely. Three db was definitely noticeable and in my opinion could easily make the difference between making a weak signal DX contact or not. I think I still have the audio files around somewhere if anyone wants a copy. However, do I think it makes sense to jam a 200 watt amp into the K3? Nope. First off, I doubt it makes sense to double the heat dissipation inside such a small rig. Secondly, 3 db more power out doesn't have the same utility as three db from the antenna, where it also benefits reception (I did buy the more expensive antenna, by the way). Thirdly, my testing indicated that even at signals as low as only 10 db above the noise level, a 3 db difference was barely noticeable. If you feel the need to be heard, buy a real amp and give yourself a couple of S-units instead of a couple of db. 73, Dave AB7E Ron D'Eau Claire wrote: IMX, it would be an undetectable change in signal strength under almost any conditions. Over the years most engineers working in HF radio systems have found that the minimum discernable change in a signal is about 3 dB (2:1 change in power) under ideal conditions. That's 3 times greater than the 'standard' for audio lab work, but what is found in practice given typical background noise, minimal QSB, etc. on an HF signal. You can test this on the air very easily. Just hook up with someone in a normal QSO and then cut your power in half and see if they notice any difference. Don't tell them what you're testing, just that you are making a change, and see if anyone can tell you what you changed. If they're looking at the S-meter on one of those absurd rigs that jumps 1 or 2 S-units for every 2 dB or so of signal change, they'll see something if you're close enough for a rock-solid signal, but they're not likely to hear it. I don't normally get excited about any major change that doesn't give me a 10:1 (10 dB) improvement in power. Now, let's not confuse that with having an efficient station. As any QRP enthusiast (or smart Ham at any power) will tell you, a dB here and a dB there eventually adds to a significant change in signal strength. But the cost/benefits ratio of doubling the power compared to the same ratio going to the legal limit usually makes such a small change a bad investment. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-200
Actually Gary, KPA-200 sounds like a good idea. I like contesting and prefer low power. The problem is that different contests define low power as 100, 150 or 200 W. It would be nice to optimize low power for any given contest. BTW, I wonder if the KAT3 would also need to be replaced. 73, Fred __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
