|
On Tue, 11 Jan 2005 03:30:07 GMT, ml wrote:
what would happen if i build say i'd have to stay physically small , so say a 1/4wave verticle on 10m and then made that antenna supercondutive? Hi OM, As far as performance? Absolutely no difference to it even if it were elevated 1000°F above that to compare. - Well maybe someone with enough sophisticated equipment might notice a dB difference - then they would whack the side of the gear to clear that up - nope, no difference.... You need to come to terms with just how imperceptible 1 dB is (zilch, in technical terms), and how much power it takes (about 12%, just more $ to burn) to make that imperceptible difference. The dollar has lost 30% of its value in the world market in the last few years - have you noticed? This may not be one way to appreciate 1dB, but it does reveal how relative changes go unfelt. 73's Richard Clark, KB7QHC |
superconducting antenna?
i just wonder does anyone know of any links to articles on a small superconducting antenna say for hf frequencies what would happen if i build say i'd have to stay physically small , so say a 1/4wave verticle on 10m and then made that antenna supercondutive? the antenna would technically have like no resistance that i know then i get fuzzy wonder what happens both technically speaking and if anyone tried it, was it a 'great' antenna rx or tx wise?? any pro's con's of such a design aside from the obv cost and impracticaliaty of pumping Lhydr/liq helium or nitrog into it etc |
A number of superconducting antennas have been built and the results
published. The ones I recall seeing were using the newer high temperature superconductors, although it can be done with conventional superconductors also. It doesn't seem to be generally known that superconductors have zero resistance only at DC. Their resistance is finite at any frequency above zero. It increases with frequency, and it also increases as the temperature rises toward the critical temperature (at which the material ceases becoming a superconductor). The resistivity of copper drops pretty dramatically at cryogenic temperatures, so copper becomes pretty hard to beat at RF, particularly if the temperature is getting anywhere near the critical temperature of the competing superconducting material. The potential advantage to be gained from a lossless antenna is that a very small, efficient antenna can be made. The problems a 1. You have a really tough matching problem, and will have severe loss in your matching network unless it's also superconducting. 2. If you do keep the antenna and matching network losses to a small value, a very small antenna will be very narrow banded. 3. You'll have to keep the temperature far below the critical temperature if you want to do much better than copper. This probably means cooling to a few degrees Kelvin, which is expensive and not compatible with putting antenna high and in the clear, let alone making one that can be rotated, for example. And the advantage of a small antenna is likely to be negated by the size of the cooling equipment. 4. Because the antenna will have finite resistance and presumably a small size, application of transmitter power will cause heating. This heat has to be removed by the refrigeration equipment to avoid raising the temperature too much. A google search on "superconducting antenna" will bring you a lot of papers, but probably not much in the way of commercial products. While interesting in the laboratory, the above problems limit the practicality of the idea. Roy Lewallen, W7EL ml wrote: i just wonder does anyone know of any links to articles on a small superconducting antenna say for hf frequencies what would happen if i build say i'd have to stay physically small , so say a 1/4wave verticle on 10m and then made that antenna supercondutive? the antenna would technically have like no resistance that i know then i get fuzzy wonder what happens both technically speaking and if anyone tried it, was it a 'great' antenna rx or tx wise?? any pro's con's of such a design aside from the obv cost and impracticaliaty of pumping Lhydr/liq helium or nitrog into it etc |
Of course Mr. Clark, as usual, is "right on the money" in saying that 1db is
nothing. To get a 1 unit s-meter difference on the average receiver, it actually takes 6 decibels more signal, or 4 times the power, from the transmitter, to produce that signal increase. Double the transmitter power (3 db) , and you get a half an s-unit increase. In many cases, it is more advantageous to raise the antenna 10 feet or more, than it is to increase transmitter power, and it will often result in much more signal in the receiver, since it gets the transmitter antenna "up in the clear", where losses to the ground and surrounding obstructions drop off.. "Richard Clark" wrote in message ... On Tue, 11 Jan 2005 03:30:07 GMT, ml wrote: what would happen if i build say i'd have to stay physically small , so say a 1/4wave verticle on 10m and then made that antenna supercondutive? Hi OM, As far as performance? Absolutely no difference to it even if it were elevated 1000°F above that to compare. - Well maybe someone with enough sophisticated equipment might notice a dB difference - then they would whack the side of the gear to clear that up - nope, no difference.... You need to come to terms with just how imperceptible 1 dB is (zilch, in technical terms), and how much power it takes (about 12%, just more $ to burn) to make that imperceptible difference. The dollar has lost 30% of its value in the world market in the last few years - have you noticed? This may not be one way to appreciate 1dB, but it does reveal how relative changes go unfelt. 73's Richard Clark, KB7QHC |
Zombie Wolf wrote:
Of course Mr. Clark, as usual, is "right on the money" in saying that 1db is nothing. Reminds me of an article in QST in the '50's titled "One dB Doesn't Matter" or something like that. This ham had one dB loss due to an old final tube, one dB loss due to a dirty tank coil, one dB loss in the low- pass filter, one dB loss in a bad solder joint, one dB loss in the tuner, one dB loss in the transmission line, and one dB loss in the antenna. He wondered why he wasn't getting out very well. :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Reminds me of an article in QST in the '50's titled
"One dB Doesn't Matter" or something like that. This ham had one dB loss due to an old final tube, one dB loss due to a dirty tank coil, one dB loss in the low- pass filter, one dB loss in a bad solder joint, one dB loss in the tuner, one dB loss in the transmission line, and one dB loss in the antenna. He wondered why he wasn't getting out very well. :-) -- ============================= No he didn't. 7dB, about one S-unit, is not enough to come to anybody's attention. It's less than the difference between a G5RV plus coax, specially a 1/2-size G5RV, and an ordinary dipole fed with open-wire line which most people never seem to notice. ---- Reg, G4FGQ |
I would argue over the simplification that below 1 db is "nothing."
If one cleans up his system then it is possible that those items that lose less than a db could add up to something "meaningfull". But DXrs say a little db is a lot and usually they are not casual operators. A single increase in gain of a db of an antenna can infact supply more gain at a lower TOA where it enables the operator to make a contact where others fail! On my antenna I am able to drive down the TOA by more than 3 degrees where for comparison purposes it may only have the gain oif a normal four element yagi that has a TOA of 14 degrees. So I consider the statement that 1db is insignificant a bit over the top when one is working with antennas and what one can achieve what others can't. Regards Art "Zombie Wolf" wrote in message ... Of course Mr. Clark, as usual, is "right on the money" in saying that 1db is nothing. To get a 1 unit s-meter difference on the average receiver, it actually takes 6 decibels more signal, or 4 times the power, from the transmitter, to produce that signal increase. Double the transmitter power (3 db) , and you get a half an s-unit increase. In many cases, it is more advantageous to raise the antenna 10 feet or more, than it is to increase transmitter power, and it will often result in much more signal in the receiver, since it gets the transmitter antenna "up in the clear", where losses to the ground and surrounding obstructions drop off.. "Richard Clark" wrote in message ... On Tue, 11 Jan 2005 03:30:07 GMT, ml wrote: what would happen if i build say i'd have to stay physically small , so say a 1/4wave verticle on 10m and then made that antenna supercondutive? Hi OM, As far as performance? Absolutely no difference to it even if it were elevated 1000°F above that to compare. - Well maybe someone with enough sophisticated equipment might notice a dB difference - then they would whack the side of the gear to clear that up - nope, no difference.... You need to come to terms with just how imperceptible 1 dB is (zilch, in technical terms), and how much power it takes (about 12%, just more $ to burn) to make that imperceptible difference. The dollar has lost 30% of its value in the world market in the last few years - have you noticed? This may not be one way to appreciate 1dB, but it does reveal how relative changes go unfelt. 73's Richard Clark, KB7QHC |
Zombie Wolf wrote:
. . .To get a 1 unit s-meter difference on the average receiver, it actually takes 6 decibels more signal, or 4 times the power, from the transmitter, to produce that signal increase. . . I'd be very interested in seeing the basis for that statement. Or are you simply and mistakenly assuming that the ficticious 6 dB "S-Unit" so fondly and inexplicably used by amateurs actually represents a division on a typical receiver S meter? Have you checked your receiver's S meter? Roy Lewallen, W7EL |
Reg Edwards wrote:
No he didn't. 7dB, about one S-unit, is not enough to come to anybody's attention. . . Yet look at all the people who go to all the trouble of putting up a 3 element beam, then think that the 7 dB gain over a dipole actually makes their signal louder. Or get a 500 watt amplifier for their 100 watt rig. Silly fools! Old wives! Roy Lewallen, W7EL |
On Wed, 12 Jan 2005 18:46:52 GMT, "
wrote: So I consider the statement that 1db is insignificant a bit over the top when one is working with antennas and what one can achieve what others can't. Hi all, This "over the top" and other straining to get a "louder" signal begs a real number - like 1dB. Such testimonials (negative or positive) are emotional comparisons. This "over the top" expression speaks for itself. If a 12% drop is outrageously "over the top," then there would be runs on the bank for the 30% fall of the dollar's value in the world market. Back when we had double-digit inflation (hmmmm, 12% is double-digit) the party now in charge went ballistic about the state of the economy. Now that we have outsourced inflation - 30% is cool. Merely a matter of who's ox is being gored. Well, so much for fun with numbers; let's look at "louder" signals. What does it mean to be "louder" with a modern (post Depression era) receiver? Is 1 dB perceived as being "louder?" Well, by definition: just barely (IFF you turn up the volume control). Why do I parenthetically add this constraint of a necessary active participation of turning up the volume control? Because in a modern receiver, the circuitry deliberately compensates for that 1dB boost by depressing the gain by the same amount. Net result? Voila! 0dB by perception and design. Well, by aural perception that is. So much for "louder." You "might" see (another perception) the S-Meter shift by something less than one needle's width if that makes you feel that something has been accomplished - in this case they could as easily calibrate the meter in ego-Satisfaction units. Then again, maybe you would have missed 1dB entirely (should we insist on a negative multipliers for that ego reading?). The correct appeal is found in S+N/N where the improvement adds clarity - merely bombasting about "loudness" is provincial. 73's Richard Clark, KB7QHC |
Richard,
you have responded to my post but frankly I miss the point or points you are trying to make. Sorry about that as I would have liked a discussion on the subject Regards Art "Richard Clark" wrote in message ... On Wed, 12 Jan 2005 18:46:52 GMT, " wrote: So I consider the statement that 1db is insignificant a bit over the top when one is working with antennas and what one can achieve what others can't. Hi all, This "over the top" and other straining to get a "louder" signal begs a real number - like 1dB. Such testimonials (negative or positive) are emotional comparisons. This "over the top" expression speaks for itself. If a 12% drop is outrageously "over the top," then there would be runs on the bank for the 30% fall of the dollar's value in the world market. Back when we had double-digit inflation (hmmmm, 12% is double-digit) the party now in charge went ballistic about the state of the economy. Now that we have outsourced inflation - 30% is cool. Merely a matter of who's ox is being gored. Well, so much for fun with numbers; let's look at "louder" signals. What does it mean to be "louder" with a modern (post Depression era) receiver? Is 1 dB perceived as being "louder?" Well, by definition: just barely (IFF you turn up the volume control). Why do I parenthetically add this constraint of a necessary active participation of turning up the volume control? Because in a modern receiver, the circuitry deliberately compensates for that 1dB boost by depressing the gain by the same amount. Net result? Voila! 0dB by perception and design. Well, by aural perception that is. So much for "louder." You "might" see (another perception) the S-Meter shift by something less than one needle's width if that makes you feel that something has been accomplished - in this case they could as easily calibrate the meter in ego-Satisfaction units. Then again, maybe you would have missed 1dB entirely (should we insist on a negative multipliers for that ego reading?). The correct appeal is found in S+N/N where the improvement adds clarity - merely bombasting about "loudness" is provincial. 73's Richard Clark, KB7QHC |
A 1 dB change in loudness is about the smallest level of change which is
fairly easily perceived by the human ear. BUT ONLY WITH AN INSTANTANEOUS, X versus Y, CHANGE IN LOUDNESS. To attempt to judge the difference, with a precision of 1 S-unit, between the loudnesses of a G5RV and a 1/2-wave dipole fed by an open-wire line, with a time lag of months, a change in the number of sunspots, on different bands, with a different receiver, is futility in the extreme. Yet some people appear to have no difficulty in making the comparison. |
On Wed, 12 Jan 2005 15:55:12 -0800, Richard Clark
wrote: |On Wed, 12 Jan 2005 18:46:52 GMT, " wrote: |So I consider the statement that 1db is insignificant |a bit over the top when one is working with antennas and what one can |achieve what others can't. | |Hi all, | |This "over the top" and other straining to get a "louder" signal begs |a real number - like 1dB. Such testimonials (negative or positive) |are emotional comparisons. One of the biggest thrills I've had in my amateur radio career was pressing the key and 2.5 seconds later hearing my signal returning from the moon. I will confess, this was an emotional response [g]. One dB does make a difference. One dB difference in transmission line loss or antenna gain makes a hell of a difference. I also got emotional when VU4RBI barely came up out of the noise and I worked her a few days before the great flood or last night when 3G0YM gave me a 59 report on 20M and not being able to tell him he was S0, I fibbed and gave him a 53. |
On Thu, 13 Jan 2005 01:44:05 GMT, "
wrote: I would have liked a discussion on the subject Hi Art, About superconducting antennas? I've researched patents for a superconductor think tank in California. Talk about more smoke than fire. Unfortunately, a poor choice of phrase, because in a newsgroup, it is more talk than smoke. errr writing than talking.... 73's Richard Clark, KB7QHC |
On Wed, 12 Jan 2005 18:59:20 -0700, Wes Stewart
wrote: I also got emotional when VU4RBI barely came up out of the noise and I worked her a few days before the great flood or last night when 3G0YM gave me a 59 report on 20M and not being able to tell him he was S0, I fibbed and gave him a 53. Hi Wes, I've heard emotional reports befo "I've got you here five by nine! Could you repeat, Could, you, re-peat?" The emotion was humor. 73's Richard Clark, KB7QHC |
In article ,
Roy Lewallen wrote: Reg Edwards wrote: No he didn't. 7dB, about one S-unit, is not enough to come to anybody's attention. . . Yet look at all the people who go to all the trouble of putting up a 3 element beam, then think that the 7 dB gain over a dipole actually makes their signal louder. Or get a 500 watt amplifier for their 100 watt rig. Silly fools! Old wives! Roy Lewallen, W7EL back on topic,.. i still ponder if i put power into a superconducting antenna if their is no resistance, and a given about of power would therefore 'stay' in the antanna longer ie no resistance and a sorta flywheel effect exists the fields would have to exist longer for fixed-given power , .. seems that all adds up to more than a trival gain looks like ill have to use some cheep material like copper or something elese i can make superconduct unless i can use a supension of conductive materials into a coolent itself an make a tube that will radiate while being superconductive just cause i wonder if that will work as good as a stp based liquid antenna who knows maybe i'll stumble over 3xtra db will the antenna stay resonant as it nears criticaltemp? and reaches it? |
This discussion kinda reminds me of a tome I read (and once actually
thought possible), from a CQ article by one "Dr. Shorza Gitchigoomie" (if i spelled that right), progonosticating on the magnicifiant effects of negative resistance! Like applying it to light bulbs (they absorb light)! Or, to electric heaters (air conditioning). If this indeed would work, then why not - the lower the power- the higher signal strength! 'Corse this article was published , in APRIL, about 40 some years ago, and in the intervening years have discovered that there are some serious flaws in his research! And I dont expect too much out of Super Conductor Antennas (if they could work well, would not they be in use at the international space station, as that temperature must be at least colder than liquid nitrogen)? or have the laws of Newtonian Physics been repealed? I await the dawning of the new age! :) Jim NN7K Richard Clark wrote: On Thu, 13 Jan 2005 01:44:05 GMT, " wrote: I would have liked a discussion on the subject Hi Art, About superconducting antennas? I've researched patents for a superconductor think tank in California. Talk about more smoke than fire. Unfortunately, a poor choice of phrase, because in a newsgroup, it is more talk than smoke. errr writing than talking.... 73's Richard Clark, KB7QHC |
back on topic,..
i still ponder if i put power into a superconducting antenna if their is no resistance, and a given about of power would therefore 'stay' in the antanna longer ie no resistance and a sorta flywheel effect exists the fields would have to exist longer for fixed-given power , .. seems that all adds up to more than a trival gain Not really, no, at least not in the commoner cases. Let's assume that you could find a superconductor which would be truly superconducting even at RF frequencies (which today's superconductors are not, I gather). So, you could cut the loss resistance of the antenna to precisely zero, in this hypothetical case. According to a note Reg posted some time ago, "At 3.75 MHz the resistance of 20 awg copper wire is 0.206 ohms per metre. Overall end-to-end dipole resistance 8.24 ohms." Using the hypothetical perfect superconductor (which may be impossible) you might reduce this dipole resistance to zero. Great reduction in loss, right? Less than you'd think. Remember, the loss resistance of 8.24 ohms appears in series with the antenna's radiation resistance (which is due to the RF energy being radiated) which will be around 70 ohms for an antenna in free space. With the loss resistance present, just under 90% of the energy is radiated ("dissipated" in the "radiation resistance"), and 10% turns into heat in the loss resistance. Getting rid of the loss resistance entirely will thus increase your radiated power by only about 10% - a small fraction of one dB. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
I would like to put a different spin on the 7dB statement below.
Where the extra gain or power really comes into play is very weak signal DXing - not the pileups necessarily. Cases in point - my Dxing log has several contacts where using a linear got my signal far enough above the noise level for the DX station to understand me. True on phone or CW. In most of these cases, the DX was calling QRZ and no one was answering -- the DX station was so weak -- seems folks just gave up or maybe everyone worked them. Turning on the linear got me the contacts. Definitely Without Question - Worked an R1MV Malyj Vysotskij, HK0 Malpelo Is, VK9/M Mellish Reef, and VP8/G So Georgia by turning on the linear feeding a vertical multibander. I had this happen enough times to realize this to be the real benefit of adding a linear. And it sure can't hurt in a pileup either, if you know how to work a pileup. -- Caveat Lector - Honor Roll 2002 Some folks Wrote No he didn't. 7dB, about one S-unit, is not enough to come to anybody's attention. . . Yet look at all the people who go to all the trouble of putting up a 3 element beam, then think that the 7 dB gain over a dipole actually makes their signal louder. Or get a 500 watt amplifier for their 100 watt rig. Silly fools! Old wives! Roy Lewallen, W7EL |
wrote:
Richard, you have responded to my post but frankly I miss the point or points you are trying to make. Join the club, Art. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
ml wrote:
i still ponder if i put power into a superconducting antenna if their is no resistance, and a given about of power would therefore 'stay' in the antanna longer ie no resistance and a sorta flywheel effect exists the fields would have to exist longer for fixed-given power , .. Using copper, the reflected current back at the feedpoint of a 1/2WL standing-wave antenna is in the ballpark of 90% of the forward current. Exactly how much improvement is possible? -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Jim - NN7K wrote:
This discussion kinda reminds me of a tome I read (and once actually thought possible), from a CQ article by one "Dr. Shorza Gitchigoomie" (if i spelled that right), progonosticating on the magnicifiant effects of negative resistance! Did your read the one about DED's? (Dark Emitting Diodes) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Ah, c'mon. Reg says 7 dB isn't enough to worry about. "Kurt Sterba" said
that even 15 dB isn't. All the people who think that linears and beams help their signals are just imagining things. The real experts say so. You're not going to listen to the old wives, are you? Roy Lewallen, W7EL -- One of Reg's "Old Wives" Caveat Lector wrote: I would like to put a different spin on the 7dB statement below. Where the extra gain or power really comes into play is very weak signal DXing - not the pileups necessarily. Cases in point - my Dxing log has several contacts where using a linear got my signal far enough above the noise level for the DX station to understand me. True on phone or CW. In most of these cases, the DX was calling QRZ and no one was answering -- the DX station was so weak -- seems folks just gave up or maybe everyone worked them. Turning on the linear got me the contacts. Definitely Without Question - Worked an R1MV Malyj Vysotskij, HK0 Malpelo Is, VK9/M Mellish Reef, and VP8/G So Georgia by turning on the linear feeding a vertical multibander. I had this happen enough times to realize this to be the real benefit of adding a linear. And it sure can't hurt in a pileup either, if you know how to work a pileup. |
The fact that superconductors have zero resistance above DC isn't a
limitation of today's technology (although technology limitations cause current high-temperature superconductors to have resistivity greater than theoretically possible), but a fundamental property of the nature of superconductors. What I'm saying is that a "truly superconducting", "hypothetical perfect" superconductor has finite resistance at any frequeny above DC. Imagining a material that has zero resistivity at frequencies above DC requires imagining something other than a superconductor. Roy Lewallen, w7EL Dave Platt wrote: . . . Let's assume that you could find a superconductor which would be truly superconducting even at RF frequencies (which today's superconductors are not, I gather). So, you could cut the loss resistance of the antenna to precisely zero, in this hypothetical case. . . . Using the hypothetical perfect superconductor (which may be impossible) you might reduce this dipole resistance to zero. Great reduction in loss, right? . . . |
In article ,
Roy Lewallen wrote: The fact that superconductors have zero resistance above DC isn't a limitation of today's technology (although technology limitations cause current high-temperature superconductors to have resistivity greater than theoretically possible), but a fundamental property of the nature of superconductors. What I'm saying is that a "truly superconducting", "hypothetical perfect" superconductor has finite resistance at any frequeny above DC. Imagining a material that has zero resistivity at frequencies above DC requires imagining something other than a superconductor. Roy Lewallen, w7EL Dave Platt wrote: . . . Let's assume that you could find a superconductor which would be truly superconducting even at RF frequencies (which today's superconductors are not, I gather). So, you could cut the loss resistance of the antenna to precisely zero, in this hypothetical case. . . . Using the hypothetical perfect superconductor (which may be impossible) you might reduce this dipole resistance to zero. Great reduction in loss, right? . . . well seems everyone is 'strictly' (narrow) focused on the antenna's resistence loss, i mentined it as the starting point as that is first thing i think of when it goes critical... however one the resistance drops, other effects take place no? both in the material and in respect to other forces aside from just resistance, once it reaches near 0 and begins being a superconductor guess i won't know until i build it and mesure it i wanted to try 10m really but 2m might be easier to keep chilly(0) and i am looking foward to rig it i've got most of the stuff i think i need so far i'd also like to build a superconductie ocilator, i'd suspect that i could power it using a truly small ammount of power? |
Perhaps the cost/benefit ratio is not viable
because of the expense to keep the antenna cold ? On spacecraft missions to the outer plantes, the antenna were not supercooled but the space environment was very cold ! |
Hi Roy -- reminds me of the time I worked an S79 on 15M phone. Very weak but
the contact was made. I posted the S79 on the DX packet cluster. A local big gun came back at me with "Miniprop sez there is absolutely no propagation to the Seychelles". I replied Oh Gosh, I had better send the QSL card back when it gets here. The QSL did arrive. I decided to keep it. I have an old wife here -- don't listen to her either hi hi. -- Caveat Lector -- I'll take an S-unit increase every time. "Roy Lewallen" wrote in message ... Ah, c'mon. Reg says 7 dB isn't enough to worry about. "Kurt Sterba" said that even 15 dB isn't. All the people who think that linears and beams help their signals are just imagining things. The real experts say so. You're not going to listen to the old wives, are you? Roy Lewallen, W7EL -- One of Reg's "Old Wives" Caveat Lector wrote: I would like to put a different spin on the 7dB statement below. Where the extra gain or power really comes into play is very weak signal DXing - not the pileups necessarily. Cases in point - my Dxing log has several contacts where using a linear got my signal far enough above the noise level for the DX station to understand me. True on phone or CW. In most of these cases, the DX was calling QRZ and no one was answering -- the DX station was so weak -- seems folks just gave up or maybe everyone worked them. Turning on the linear got me the contacts. Definitely Without Question - Worked an R1MV Malyj Vysotskij, HK0 Malpelo Is, VK9/M Mellish Reef, and VP8/G So Georgia by turning on the linear feeding a vertical multibander. I had this happen enough times to realize this to be the real benefit of adding a linear. And it sure can't hurt in a pileup either, if you know how to work a pileup. |
Wefax_Dude wrote:
Perhaps the cost/benefit ratio is not viable because of the expense to keep the antenna cold ? It's certainly more economical to increase the transmitter's power output than to supercool a dipole. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Real world experience: If the bands up you might not be able to tell
the difference, when its down its the difference between no copy and Q-5 ****** It's a relative, not an absolute. 73 WG8Z Yet look at all the people who go to all the trouble of putting up a 3 element beam, then think that the 7 dB gain over a dipole actually makes their signal louder. Or get a 500 watt amplifier for their 100 watt rig. Silly fools! Old wives! Roy Lewallen, W7EL Greg Z to thine own sound be true WG8Z |
In article , Cecil Moore
wrote: ? It's certainly more economical to increase the transmitter's power output than to supercool a dipole. it think this statement is not totally correct, as if someone manages to build an antenna that serves some pourpose that achieves it's built p goal, then it's worth the expense for certain additionally... who knows maybe sombody might invent somthing that is more efficient or discover something like a benificial offshoot.. who knws what the cost will be one day to supercool a antenna, of which dipole is one of many kinds |
On Fri, 14 Jan 2005 01:53:31 GMT, ml wrote:
who knows maybe sombody might invent somthing that is more efficient or discover something like a benificial offshoot.. Who knows indeed? It may be the next penicillin for diesel knock. who knws what the cost will be one day to supercool a antenna, of which dipole is one of many kinds Who knws undeed! It could pcost as much as the national debt of Liechtenstein which isn't big enough to field a full sized 16 KHz superhip antenna for communications to their solar powered submarine fleet. But if the fate of whirled peas hinges upon their sacrifice, cost be DAMNED! 73's Richard Clark, KB7QHC |
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