KX3 and Data modes
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I have not had any experience using data modes in
low power radios. Will the KX3 be nearly as effective using data modes as it will be using CW? From what I read in the preliminary manual I guess it is possible to connect a portable PC with data software to use the data modes in addition to the self-contained capability. I would assume SSB to be the least effective mode of operation among the KX3 modes. Dave - KO4KL ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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On Tue, Mar 13, 2012 at 9:56 AM, David Stratton <[hidden email]> wrote:
>...Will the KX3 be nearly as effective > > using data modes as it will be using CW?... ============ Dave, for miles-per-watt the king of the hill is JT-65HF. (However, it's not a whole lot of fun IMHO) Theoretically one can communicate with a signal path about 6 db weaker than needed for CW. PSK and CW are about on a par theoretically. For SSB the signal path has to be about 9 db better than for CW or PSK. Of course, the above applies to any radio, KX3 or otherwise, QRP or QRO. Many hams have great fun using SSB with low-power radios. I guess I come from the other universe. Of the thousands of QRP contacts I've made, only one was on SSB. It was with Martti, OH2BH, who patiently spent about 3 minutes digging to get my call, one letter at a time. After that one I went back to CW. Tony KT0NY -- http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by David Stratton
Dave-
The digital mode I find most usable and robust is Olivia. It is quite a bit better than PSK31 and sounds great too. MultiPSK is a wonderful free program that has virtually all digital modes. A small netbook would be ideal to pair with the KX-3. 5 watts and a good antenna will be very effective with Olivia. I just have to stop thinking about the KX-3 -and the day will arrive sooner! Bob-AB5N |
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This post was updated on .
Bob,
Saw your callsign, and would like to mention that if you ever develop a hand mic for the K3 etc, please let us know. The ic-7000 mic kit I got from you years back works A1. Sorry for being OT. Hope you enjoy the KX3. Adrian ... vk4tux |
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In reply to this post by David Stratton
OK, I guess I need to repeat what I said. The 25H is SPECIAL order
from Radiodan W7RF <<mailto:[hidden email]>[hidden email]>, who has the ability to run NBS traceable calibration on these elements. Any Bird element can be modified to a different power range (if you do a search you should find some sites that talk to this). But most of us do not want to dig into one that far. I think the wrong impression has been taken of Bird's statement of accuracy. I doubt the inaccuracy is a fixed amount that is the same at any reading. More likely Bird does its calibrations at full scale and this is the accuracy that they will warrantee. Seem more reasonable that the error is relative to the level of the reading. The actual adjustment is a variable cap inside the element. That and a resistor determine the level the element functions at. But that being said, I have no proof the element in question is any better than reading 25w +/- 1.25w. Ideally, I would have sent the meter to Radiodan to be calibrated with the element. Then he could have specified what the accuracy was for the calibration. But this is a brand-new element, freshly calibrated. Should I doubt it in favor of my 35 year old 100H element? Especially since resolution of reading 12w is much worse on the 100 scale than on the 25 scale. There is only one way for me to determine what the accuracy is. That is by observing the waveform across the dummy load with my scope, calculating Vrms from the peak-peak voltage and using that to determine power using V^2/R, assuming the load is not reactive. Well I might do that out of curiosity. That is probably the most accurate way for most hams to measure power (unless you are very rich and own a calorimeter). I did power measurement at 500-KHz by using my scope since I have no elements that work below 2-MHz. My 100w 500-KHz transmitter is equipped with an RF ammeter for measuring/monitoring power. For normal daily ham measurements I am willing to assume that the new element is my most accurate. Will it matter much if I am off 1.25w? BTW it could be better than that. That is the worse-case specification. 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-? DUBUS Magazine USA Rep [hidden email] "Kits made by KL7UW" http://www.kl7uw.com/kits.htm ====================================== ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I have one of these installed in my Bird 43, from ebay;
Has a 2x and 5x range (adjustable to other multipliers, I have mine setup 2x & 4 x. Pep and avg readings too, works v-well and excellent value. Installed mine over a year ago, and no issues . Adrian … vk4tux From: Edward R. Cole [via Elecraft] [mailto:[hidden email]] OK, I guess I need to repeat what I said. The 25H is SPECIAL order If you reply to this email, your message will be added to the discussion below: http://elecraft.365791.n2.nabble.com/KX3-and-Data-modes-tp7368721p7371108.html To unsubscribe from KX3 and Data modes, click here. |
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In reply to this post by Edward R Cole
KL7UW wrote:
> I think the wrong impression has been taken of Bird's statement of accuracy. I doubt the inaccuracy is a fixed amount that is the same at any reading. More likely Bird does its calibrations at full scale and this is the accuracy that they will warrantee. Seem more reasonable that the error is relative to the level of the reading. The actual adjustment is a variable cap inside the element. That and a resistor determine the level the element functions at. The manufacturer's accuracy specification is what it is...not what you might think is "reasonable". Most analog meters are calibrated in % full scale due to the inherent error in visually interpreting a needle on an analog scale. This visual error is constant at all readings, hence the specification is a percentage of full scale. This is exactly why DMMs replaced analog meters (e.g. Simpson, Triplett, etc) decades ago. > But that being said, I have no proof the element in question is any better than reading 25w +/- 1.25w. Ideally, I would have sent the meter to Radiodan to be calibrated with the element. Then he could have specified what the accuracy was for the calibration. The LP-100A is factory calibrated (NIST traceable in 11 frequency bands) to 5% of reading (3% typical). As stated before, the key difference with the analog Bird is that accuracy is specified in % of reading...not % of full scale. > There is only one way for me to determine what the accuracy is. That is by observing the waveform across the dummy load with my scope, calculating Vrms from the peak-peak voltage and using that to determine power using V^2/R, assuming the load is not reactive. Well I might do that out of curiosity. That is probably the most accurate way for most hams to measure power (unless you are very rich and own a calorimeter). I did power measurement at 500-KHz by using my scope since I have no elements that work below 2-MHz. My 100w 500-KHz transmitter is equipped with an RF ammeter for measuring/monitoring power. This is essentially what the LP-100A does using an A/D converter and microprocessor. Besides being much more accurate, it provides many other useful features such as Z, R, X, SWR, SWR and phase versus frequency, Smith Chart output, translates coupler load Z to antenna load Z (for remote measurements), peak-to-average (useful for measuring SSB compression), etc. Measurement range is 1-3000 Watts over 1.8-54 MHz with the standard coupler (higher power available as options) at full rated accuracy. > For normal daily ham measurements I am willing to assume that the new element is my most accurate. Will it matter much if I am off 1.25w? BTW it could be better than that. That is the worse-case specification. I can understand being locked in to Bird because of your significant investment in 16 slugs (typically $60-80 each on eBay not counting the Bird 43 itself). However, for anyone considering a truly state-of-the art Wattmeter, it's hard to beat N8LP's LP-100A because it does so much more than simply measuring power. If you add up the total cost of a Bird plus multiple slugs to cover the same power ranges, the LP-100A is a steal. Like all of Larry's products (LP-PAN, LP-Bridge, etc) the engineering and support for the LP-100A is first rate (e.g. providing a customer upgrade path from the original LP-100 to the LP-100A). http://www.telepostinc.com/ I have no connection with Larry other than being a very satisfied customer with several of his products. 73, Bill W4ZV |
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In reply to this post by Edward R Cole
Ed,
Yes, the most accurate is to use the 'scope with a 10X probe to measure the RF voltage across the dummy load. No need to convert to RMS and all that - use this formula - Power = the square of the peak to peak RF voltage divided by 400 if the load is 50 ohms (8R if other than 50 ohms). You can substantiate that by formula manipulation - the sqrt of 2 terms fall out. 73, Don W3FPR On 3/14/2012 3:56 AM, Edward R. Cole wrote: > There is only one way for me to determine what the accuracy > is. That is by observing the waveform across the dummy load with my > scope, calculating Vrms from the peak-peak voltage and using that to > determine power using V^2/R, assuming the load is not reactive. Well > I might do that out of curiosity. That is probably the most > accurate way for most hams to measure power (unless you are very rich > and own a calorimeter). I did power measurement at 500-KHz by using > my scope since I have no elements that work below 2-MHz. My 100w > 500-KHz transmitter is equipped with an RF ammeter for > measuring/monitoring power. > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by David Stratton
Well we have taken this off topic a bit.
Bill W4ZV writes of the advantages of the LP-100A over analog meters. Definitely a nice piece of equipment that can do much more than a simple power meter. However, it only reads to 54 MHz. I also occupy 144/222/432/927/1296/2400/3400/10,368 MHz bands so I need to read power to 10-GHz. With the Bird43 I can get up to 2.4 GHz with expensive elements (I have a 10K for 1100-1800 MHz). Then I switch to my HP432A mw power meter which is limited to +10mw, but can read to 18 GHz. I have 900w directional couplers and coaxial attenuators for measuring higher power with the HP meter. Also, I would not feel comfortable using the LP-100A at 50-foot in a light rain on my tower checking cable loss or power levels. The Bird is the industry standard instrument for field use (inaccurate as it is). So this is NOT and argument of what is "better". If some day I can afford it, the LP-100 would be real nice in my shack. For 99% of the readers on this reflector the LP-100A will suit them perfectly. The other 1% of us have different/additional needs. I suppose we have beat the Bird to death? Oh joy, its snowing! 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-? DUBUS Magazine USA Rep [hidden email] "Kits made by KL7UW" http://www.kl7uw.com/kits.htm ====================================== ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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