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Supposed comparison of Mobile HF Antennas in November QST
I almost could not believe that an article that starts out with using an
antenna tuner to deliver all possible power to mobile HF antennas got published. I also noted that the testing antenna was 360 feet away. I'm waiting to read on here that I've mis-understood a great method of measuring HF mobile antennas, but absent a troll or two, I don't expect too. |
Supposed comparison of Mobile HF Antennas in November QST
On Thu, 25 Oct 2007 23:02:12 -0400, Art Clemons
wrote: I'm waiting to read on here that I've mis-understood a great method of measuring HF mobile antennas, but absent a troll or two, I don't expect to. Yeah, that was ugly. I also noticed the author used what appeared to be a base loaded motorized antenna and then concluded that the motorized antennas weren't worth a hoot. There are some decent center loaded ones out there that would have given better results. Base loaded antennas are probably the worst possible case, based on my experience. Wonder how that article made it past the editor? S.T.W. |
Supposed comparison of Mobile HF Antennas in November QST
On Oct 26, 1:43 am, Sum Ting Wong wrote:
On Thu, 25 Oct 2007 23:02:12 -0400, Art Clemons wrote: I'm waiting to read on here that I've mis-understood a great method of measuring HF mobile antennas, but absent a troll or two, I don't expect to. Yeah, that was ugly. I also noticed the author used what appeared to be a base loaded motorized antenna and then concluded that the motorized antennas weren't worth a hoot. There are some decent center loaded ones out there that would have given better results. Base loaded antennas are probably the worst possible case, based on my experience. Wonder how that article made it past the editor? S.T.W. Publish or perish? denny |
Supposed comparison of Mobile HF Antennas in November QST
BTW, here is the email I sent to QST after reading that article...
************************************************** ********************* I know that as a business owner that customers only say something when they are not happy... As your customer I have to say that the QST article comparing various mobile antenna configurations appears to be a bad decision... The methodology is non existant and the information imparted is thin gruel indeed... I can only assume you are having problems finding articles elementary enough to satisfy your target membership of new hams who have rudimentary technical knowledge... Let me urge you to return with us now to those thrilling days of yesteryear when QST set a technical standard and stimulated the young hams reading it to learn and understand, rather than simply sliding down to our level... Success and leadership is not exclusively defined by circulation numbers - rather it is more defined by the standing and esteem it is held in by the rest of the amateur, technical, and professional community... ************************************************** ******************************* denny / k8do |
Supposed comparison of Mobile HF Antennas in November QST
Sum Ting Wong wrote:
Yeah, that was ugly. I also noticed the author used what appeared to be a base loaded motorized antenna and then concluded that the motorized antennas weren't worth a hoot. There are some decent center loaded ones out there that would have given better results. Base loaded antennas are probably the worst possible case, based on my experience. Wonder how that article made it past the editor? I added a top hat and "RV extension" to my HS-1600 that doubled the length of the bottom section. Here's a picture and the combined results of three CA shootouts from about 20 years ago. There don't seem to have been any break-throughs since then. -- 73, Cecil http://www.w5dxp.com |
Supposed comparison of Mobile HF Antennas in November QST
Denny wrote:
Let me urge you to return with us now to those thrilling days of yesteryear when QST set a technical standard and stimulated the young hams reading it to learn and understand, rather than simply sliding down to our level. Right on, Denny. Where is Larsen E. Rapp when we need him? :-) -- 73, Cecil http://www.w5dxp.com |
Supposed comparison of Mobile HF Antennas in November QST
On Oct 25, 10:02 pm, Art Clemons wrote:
I almost could not believe that an article that starts out with using an antenna tuner to deliver all possible power to mobile HF antennas got published. I know quite a few people that want to try that set up. Without fail, I warn against it. Some listen, some don't.. But that's ok, sometimes failure is the best teacher... Whats really bad is the few die hards that run those and think they are world beaters. One will tell my friends they are the greatest thing since sliced bread, and then I'll have to tell em, no no no... After a while they don't know who to believe... So I often have to let them learn the hard way. I assume the "die hards" don't try anything else to compare with.. I haven't read the article, as I don't QST, but if they recommended that thing as a good performing antenna, they should be flogged. MK |
Supposed comparison of Mobile HF Antennas in November QST
Art Clemons wrote:
"I don`t expect too." Why all the Andy Rooney crap here? No problem with a tuner. "The input power was the same on each antenna." No problem with 360 feet. Received carrier power is proportional to radiated power at that distance along the horiaontal path. Best regards, Richard Harrison, KB5WZI |
Supposed comparison of Mobile HF Antennas in November QST
On Fri, 26 Oct 2007 13:16:14 GMT, Cecil Moore wrote:
Denny wrote: Let me urge you to return with us now to those thrilling days of yesteryear when QST set a technical standard and stimulated the young hams reading it to learn and understand, rather than simply sliding down to our level. Right on, Denny. Where is Larsen E. Rapp when we need him? :-) Maybe QST has hired Hashafisti Scratchi away from CQ? |
Supposed comparison of Mobile HF Antennas in November QST
"Cecil Moore" wrote in message et... Sum Ting Wong wrote: Yeah, that was ugly. I also noticed the author used what appeared to be a base loaded motorized antenna and then concluded that the motorized antennas weren't worth a hoot. There are some decent center loaded ones out there that would have given better results. Base loaded antennas are probably the worst possible case, based on my experience. Wonder how that article made it past the editor? I added a top hat and "RV extension" to my HS-1600 that doubled the length of the bottom section. Here's a picture and the combined results of three CA shootouts from about 20 years ago. There don't seem to have been any break-throughs since then. -- 73, Cecil http://www.w5dxp.com Cecil, I haven't read the article, but if the guy is claiming that his "tuner' thing is better than a center-loaded bugcatcher or reasonable sized screwdriver (FULL sized), I would LOVE to get in on any wagers he is prepared to entertain! (Snickers and unintentional "razzberries" beginning a crescendo and bursting into loud, uncontrollable guffaws and knee slaps!) You mean they actually allow people like THAT to WRITE that s--- in magazines? 73 Jerry K4KWH |
Supposed comparison of Mobile HF Antennas in November QST
Didn't SGC have a version of a tuner that sort of clamped on an outside car
window and had an 8 foot vertical rising from it ? Did anyone here ever use one and what were the results ? Nick (in UK - don't see QST) |
Supposed comparison of Mobile HF Antennas in November QST
|
Supposed comparison of Mobile HF Antennas in November QST
QST editors can't be expected to be experts on all the topics they have
to deal with. Over the years, they've dealt with the problem in various ways. One was to establish a pool of "Technical Advisors" -- volunteers who had particular expertise in various areas. Some manuscripts being considered for publication were sent to the appropriate TAs for comments and review. This practice slowly died out, but I don't know why. I suspect it was because the editors seldom had the time for this step in the process due to erratic scheduling. Eventually, they adopted a solution which was easy on the editors and their schedules: post the proposed articles to a restricted web site where the TAs could review them and leave comments. This saved the time of communicating with individual TAs, and made it unnecessary to wait for a response -- if comments weren't there by the deadline, too bad. What I saw as one problem with this approach was that comments and analyses were regularly being made by TAs whose appointments had nothing at all to do with the subject matter. As an example (not representing any actual particular occurrence), a TA whose expertise was, say, legal matters or publicity would review (for technical content) an article on phased arrays. As far as I could tell, their reviews were weighted equally to those from people who really understood the topic. In any case, the one or few reviews from knowledgeable people were generally lost in the noise. I don't know if this is the method still being used -- I resigned my TA appointment several years ago when it became apparent that I was no longer able to make any substantial contribution. I know of at least a couple of very knowledgeable people who have done likewise. This is a shame, because they're perfectly willing to provide free technical assistance, yet the ARRL doesn't seem able to find a way to take advantage of it. I'm not sure they've ever solved the problem of editors who don't understand the material modifying it in such a way as to make it no longer true. In all cases but one when this happened to me, I was able to correct the problems before publication. In one case, however, I wasn't given enough time to correct the numerous misinterpretations, invalid "explanations", and other seriously wrong modifications made by the editor and had to pull the article(*). Several extremely capable people I know, however, have had serious errors introduced to their articles by the editor *after their final review*, so they didn't even get to see the errors until the article was published under their name. Most of these people will never write for QST again as a result. This is one of the reasons that QST has a smaller pool of knowledgeable and capable authors to draw from. So when you see a technically weak article in QST, the author might not be entirely at fault. (*) I want to make it clear that I'm very aware that my writing and communicating skills aren't all that great, and I really appreciate having an editor improve the style, clarity, and brevity of my writing, as well as questioning any weak or inconsistent arguments I've made. [A good editor would have cut half the words from the preceding sentence, and made it a lot clearer at the same time.] So I welcome editing. What I do object to is editing which changes the core meaning of the content and/or results in its being technically incorrect. Roy Lewallen, W7EL |
Supposed comparison of Mobile HF Antennas in November QST
On 26 Oct, 13:12, Roy Lewallen wrote:
QST editors can't be expected to be experts on all the topics they have to deal with. Over the years, they've dealt with the problem in various ways. One was to establish a pool of "Technical Advisors" -- volunteers who had particular expertise in various areas. Some manuscripts being considered for publication were sent to the appropriate TAs for comments and review. This practice slowly died out, but I don't know why. I suspect it was because the editors seldom had the time for this step in the process due to erratic scheduling. Eventually, they adopted a solution which was easy on the editors and their schedules: post the proposed articles to a restricted web site where the TAs could review them and leave comments. This saved the time of communicating with individual TAs, and made it unnecessary to wait for a response -- if comments weren't there by the deadline, too bad. What I saw as one problem with this approach was that comments and analyses were regularly being made by TAs whose appointments had nothing at all to do with the subject matter. As an example (not representing any actual particular occurrence), a TA whose expertise was, say, legal matters or publicity would review (for technical content) an article on phased arrays. As far as I could tell, their reviews were weighted equally to those from people who really understood the topic. In any case, the one or few reviews from knowledgeable people were generally lost in the noise. I don't know if this is the method still being used -- I resigned my TA appointment several years ago when it became apparent that I was no longer able to make any substantial contribution. I know of at least a couple of very knowledgeable people who have done likewise. This is a shame, because they're perfectly willing to provide free technical assistance, yet the ARRL doesn't seem able to find a way to take advantage of it. I'm not sure they've ever solved the problem of editors who don't understand the material modifying it in such a way as to make it no longer true. In all cases but one when this happened to me, I was able to correct the problems before publication. In one case, however, I wasn't given enough time to correct the numerous misinterpretations, invalid "explanations", and other seriously wrong modifications made by the editor and had to pull the article(*). Several extremely capable people I know, however, have had serious errors introduced to their articles by the editor *after their final review*, so they didn't even get to see the errors until the article was published under their name. Most of these people will never write for QST again as a result. This is one of the reasons that QST has a smaller pool of knowledgeable and capable authors to draw from. So when you see a technically weak article in QST, the author might not be entirely at fault. (*) I want to make it clear that I'm very aware that my writing and communicating skills aren't all that great, and I really appreciate having an editor improve the style, clarity, and brevity of my writing, as well as questioning any weak or inconsistent arguments I've made. [A good editor would have cut half the words from the preceding sentence, and made it a lot clearer at the same time.] So I welcome editing. What I do object to is editing which changes the core meaning of the content and/or results in its being technically incorrect. Roy Lewallen, W7EL But "experts" are usually diehards and unwilling to accept, analyse, or review change. Can you imagine some of the "experts" on this group having a hand at what should be printed and what was hogwash? Maybe it is time to govern science by the polls. Art |
Supposed comparison of Mobile HF Antennas in November QST
Jerry wrote:
I haven't read the article, but if the guy is claiming that his "tuner' thing is *better than a center-loaded bugcatcher or reasonable sized screwdriver (FULL sized), I would LOVE to get in on any wagers he is prepared to entertain! (Snickers and unintentional "razzberries" beginning a crescendo and bursting into loud, uncontrollable guffaws and knee slaps!) No, it wasn't quite that bad. The author though seems to have used a tuner to match to the antennas being tested and then coming to some conclusion about how well said antenna radiated energy to a relatively nearby field strength meter (360 feet). One basic problem is that you then end up with some signal level which may or may not be equal to the original output from the rig (apparently an ICOM 706-MKIIG) reaching the antenna. That might make the rig happy but it does leave the antenna with an awfully funny feed at times, one that could be oh 3 dB or so down from what the rig puts out. |
Supposed comparison of Mobile HF Antennas in November QST
Richard Harrison wrote:
No problem with a tuner. "The input power was the same on each antenna." How can the input power be the same if it's going through the tuner? The input power is the same at the input of the tuner, but we have absolutely no idea what the output power from the tuner is. Isn't that a problem for a fair test? Would not a more reasonable approach be to use something like Wattmeter and get the antenna resonant? I've seen folks who used antenna tuners find out the tuner can get really hot into some loads? If the tuner is consuming some of the RF as heat, that's power not reaching the antenna ergo not a fair test. No problem with 360 feet. Received carrier power is proportional to radiated power at that distance along the horiaontal path. Isn't 360 feet within the near RF field at most HF frequencies? |
Supposed comparison of Mobile HF Antennas in November QST
I haven't read the article, but are different mobile antennas being
compared on different vehicles, or the same vehicle? It's amazing how many people don't realize that the vehicle is fully half the antenna, and may in many cases play a more important role in determining overall radiating efficiency than the supposed "antenna". So it's impossible to draw any conclusions about mobile antennas based on comparisons done when they're mounted on different vehicles. It's as much a test of the vehicle's effectiveness as a radiator as it is the antenna's. Roy Lewallen, W7EL |
Supposed comparison of Mobile HF Antennas in November QST
Roy Lewallen wrote:
QST editors can't be expected to be experts on all the topics they have to deal with. Over the years, they've dealt with the problem in various ways. One was to establish a pool of "Technical Advisors" -- volunteers SNIP Didn't look to see what you are using to post but could you please set your line length correctly. Sixty eight characters would do fine! (E.G. as Thunderbird has corrected your post above.) Thanks, Charlie. -- M0WYM www.radiowymsey.org |
Supposed comparison of Mobile HF Antennas in November QST
Roy Lewallen wrote:
I haven't read the article, but are different mobile antennas being compared on different vehicles, or the same vehicle? It's amazing how many people don't realize that the vehicle is fully half the antenna, and may in many cases play a more important role in determining overall radiating efficiency than the supposed "antenna". So it's impossible to draw any conclusions about mobile antennas based on comparisons done when they're mounted on different vehicles. It's as much a test of the vehicle's effectiveness as a radiator as it is the antenna's. Same vehicle, at least that part was correct |
Supposed comparison of Mobile HF Antennas in November QST
charlie wrote:
Didn't look to see what you are using to post but could you please set your line length correctly. Sixty eight characters would do fine! (E.G. as Thunderbird has corrected your post above.) Roy seems to be using T'Bird which if I remember correctly defaults to 72 characters per line. Roy's post showed up fine in Knode here too. |
Supposed comparison of Mobile HF Antennas in November QST
charlie wrote:
Roy Lewallen wrote: QST editors can't be expected to be experts on all the topics they have to deal with. Over the years, they've dealt with the problem in various ways. One was to establish a pool of "Technical Advisors" -- volunteers SNIP Didn't look to see what you are using to post but could you please set your line length correctly. Sixty eight characters would do fine! (E.G. as Thunderbird has corrected your post above.) I'm using Thunderbird 2.0.0.6, which defaults to flowed rather than fixed width format. Please see http://kb.mozillazine.org/Fixed_width_messages. When flowed text messages are viewed with Thunderbird (at least with mine), they wrap to the window width. If the flowed format is causing a problem for other readers, please email me. If it is a general problem I can force it to post in fixed line width. But let's take the discussion off line. Roy Lewallen, W7EL |
Supposed comparison of Mobile HF Antennas in November QST
On Oct 26, 1:20 pm, Michael Coslo wrote:
I've considered putting a tuner on my Bugcatcher for 80 meters, but haven't. The thing is so narrow there that the alternative is two taps for the phone portion of the band. That would more more for impedance matching rather than the loading coil itself. I have no real problem with that. I've often used simple L network tuners for matching mobile antennas. The system I have a problem with is using the tuner as the loading coil itself. It's usually a disaster as far as efficiency. Maximum current is at the coil, and often that coil will be surrounded by body metal. Not good.. Poor current distribution through the whip, and low overall efficiency. Not good.. If they left out bugcatchers in the test, no wonder all those tuner fed things looked so good... :( If your antenna acts very "high Q", that's actually good. :) It means it's probably a pretty decent radiator. I'd be more worried if it acted overly broadbanded, or low Q. You won't lose much if you use a tuner for Z matching in your case. MK |
Supposed comparison of Mobile HF Antennas in November QST
On Oct 26, 5:53 pm, Art Clemons wrote:
Richard Harrison wrote: No problem with a tuner. "The input power was the same on each antenna." How can the input power be the same if it's going through the tuner? The input power is the same at the input of the tuner, but we have absolutely no idea what the output power from the tuner is. Isn't that a problem for a fair test? Would not a more reasonable approach be to use something like Wattmeter and get the antenna resonant? I've seen folks who used antenna tuners find out the tuner can get really hot into some loads? If the tuner is consuming some of the RF as heat, that's power not reaching the antenna ergo not a fair test. I may be missing the story...Is he feeding all these whips with the tuner alone, with no loading coil, or he feeding coil loaded antennas with a tuner for impedance matching? I got the impression he was using the tuner alone, with no other loading coils on the whips. I have no real problem with using a tuner for impedance matching as long as it's not the actual loading coil. I guess without seeing the article, it's hard to tell what his point is. MK |
Supposed comparison of Mobile HF Antennas in November QST
Art Clemons wrote:
"Would not a more reasonable approach be to use something like a Wattmeter and get the antenna resonant?" You have a point. The wattmeter was on the input to the tuner and we don`t know what the tuner`s loss is. If the loss is negligible, everything should be OK, and "the input power was the same on each antenna." Best regards, Richard Harrison, KB5WZI |
Supposed comparison of Mobile HF Antennas in November QST
On Oct 27, 12:15 am, (Richard Harrison)
wrote: Art Clemons wrote: "Would not a more reasonable approach be to use something like a Wattmeter and get the antenna resonant?" You have a point. The wattmeter was on the input to the tuner and we don`t know what the tuner`s loss is. If the loss is negligible, everything should be OK, and "the input power was the same on each antenna." Best regards, Richard Harrison, KB5WZI I received back a fairly detailed email from the QST editor involved... I will reply to him next week... I will incorporate some of the comments on here - with attribution to the author(s).. Everything (except private comments) will be shared here... Right now, back to the inhumane QRN on 80 meter cqww... denny / k8do |
Supposed comparison of Mobile HF Antennas in November QST
On Thu, 25 Oct 2007 23:02:12 -0400, Art Clemons
wrote: I almost could not believe that an article that starts out with using an antenna tuner to deliver all possible power to mobile HF antennas got published. I also noted that the testing antenna was 360 feet away. I'm waiting to read on here that I've mis-understood a great method of measuring HF mobile antennas, but absent a troll or two, I don't expect too. As a Student of the Art of Amateur Radio with a special fondness for antennas I found the article useful and interesting. At least as far as it went! Last year I purchased a radio especially to go mobile. I have yet to find an acceptable mobile HF antenna to use on my Chrysler Minivan. I am beginning to believe that there are no acceptable solutions to the problem as I define it. Further, I have concluded that ALL MOBILE HF installations are poor compared to a dipole five feet off the ground, some are just worse than others. The article simply sheds some light on the practical issues one encounters with popular alternatives. I think an auto tuner with whatever whip length one can tolerate is the best one can do with a Chrysler Minivan. Modeling programs do not consider the radiation from the loading coils but field measurements do. Tuner losses can be estimated from the software in the Arrl Antenna Books. If you can write a better article for QST, please do so. But please remember, most of us don't choose the ethical we drive because of its ability to carry a less bad radio antenna! John Ferrell W8CCW "Life is easier if you learn to plow around the stumps" |
Supposed comparison of Mobile HF Antennas in November QST
On Sun, 28 Oct 2007 10:30:35 -0400, John Ferrell
wrote: I think an auto tuner with whatever whip length one can tolerate is the best one can do with a Chrysler Minivan. Get yourself a copy of AA6GL's "MOBILE.EXE" antenna program and try various configurations. I'll bet you a (jelly!) donut that your perception will change. S.T.W. |
Supposed comparison of Mobile HF Antennas in November QST
Art Clemons wrote:
SNIP Roy seems to be using T'Bird which if I remember correctly defaults to 72 characters per line. Roy's post showed up fine in Knode here too. Yes, I noticed later that he was using TB in which my default is 68 but 72 would do :) Maybe Knode automatically wraps the lines? Charlie. -- M0WYM www.radiowymsey.org |
Supposed comparison of Mobile HF Antennas in November QST
John Ferrell wrote:
. . . Modeling programs do not consider the radiation from the loading coils but field measurements do. . . . Modeling programs do indeed include radiation from the loading coils, provided that they're modeled as a wire helix rather than by use of the lumped load object. EZNEC and NEC both have methods of automatically creating a helix, making this process very easy. I believe most other NEC based modeling programs also have this capability. Roy Lewallen, W7EL |
Supposed comparison of Mobile HF Antennas in November QST
John Ferrell wrote:
I think an auto tuner with whatever whip length one can tolerate is the best one can do with a Chrysler Minivan. That will work pretty well for 20m-10m. Modeling programs do not consider the radiation from the loading coils but field measurements do. EZNEC can model helical coils that does consider radiation from the coil. -- 73, Cecil http://www.w5dxp.com |
Supposed comparison of Mobile HF Antennas in November QST
On Sun, 28 Oct 2007 14:52:13 -0700, Roy Lewallen
wrote: John Ferrell wrote: . . . Modeling programs do not consider the radiation from the loading coils but field measurements do. . . . Modeling programs do indeed include radiation from the loading coils, provided that they're modeled as a wire helix rather than by use of the lumped load object. EZNEC and NEC both have methods of automatically creating a helix, making this process very easy. I believe most other NEC based modeling programs also have this capability. Roy Lewallen, W7EL Ooops! I have not used that part of EZNEC yet so I accept I was wrong. I will have to look a little deeper into why I was convinced that the radiation from loading coils was not considered. I still don't find a problem with publishing the article. If nothing else it has generated discussion. John Ferrell W8CCW "Life is easier if you learn to plow around the stumps" |
Supposed comparison of Mobile HF Antennas in November QST
Jimmie D wrote:
I once saw a demonstration that "BIG UGLY" cb antennas, these are approximately 1/8 wl and have a huge loading coil, have more gain than a 1/4 wl radiator. This certaily appeared to be the case when both the antenna being test and the field strength meter's antenna were both the "big ugly" variety and relatively close together(50'). Could this "gain" be a result of magnetic coupling between the coils or was some other trickery being performed. There's no doubt this was some sort of trickery. I'd bet any amount of money that if properly measured, the loaded 1/8 wave antenna would be shown to have less gain due to lower efficiency. Even moderately accurate antenna gain measurements are much more difficult to make than most people realize, and there are many ways to be fooled. I couldn't begin to list the all ways you could set up a demonstration like that to get whatever result you desired. Roy Lewallen, W7EL |
Supposed comparison of Mobile HF Antennas in November QST
Jimmie D wrote:
I once saw a demonstration that "BIG UGLY" cb antennas, these are approximately 1/8 wl and have a huge loading coil, have more gain than a 1/4 wl radiator. This certaily appeared to be the case when both the antenna being test and the field strength meter's antenna were both the "big ugly" variety and relatively close together(50'). Could this "gain" be a result of magnetic coupling between the coils or was some other trickery being performed. Most likely trickery but could conceivably be achieved through phasing of co-linear radiators. The total radiated power was no doubt less than the 1/4WL but the phasing might have caused constructive interference in the remaining RF waves in the direction of the detector. A loaded CB antenna does not normally require a "huge loading coil" so it may have been a phase-reversing coil of sorts as described by Kraus. -- 73, Cecil http://www.w5dxp.com |
Supposed comparison of Mobile HF Antennas in November QST
Very interesting, indeed. This probably accounts for the gradual shift (not
for the better) in QST technical articles over a number of years. There seems to be more "publicity oriented" wording than precise technical content compared to twenty or thirty years ago. I had assumed this was an intentional effort to better address new hams, but I see it may have been due to the editing process. This editing problem is certainly not confined to QST. One of the few things that sends my blood pressure to an astronomical level is for an editor to make changes they do not understand. I depend on various font and indentation settings for much of my material; now and then an editor will decide to "standardize" these and I go completely off the wall. Unfortunately, in many organizations the editors usually have the last shot at material. Bill - W2WO "Roy Lewallen" wrote in message ... QST editors can't be expected to be experts on all the topics they have to deal with. Over the years, they've dealt with the problem in various ways. One was to establish a pool of "Technical Advisors" -- volunteers who had particular expertise in various areas. Some manuscripts being considered for publication were sent to the appropriate TAs for comments and review. This practice slowly died out, but I don't know why. I suspect it was because the editors seldom had the time for this step in the process due to erratic scheduling. Eventually, they adopted a solution which was easy on the editors and their schedules: post the proposed articles to a restricted web site where the TAs could review them and leave comments. This saved the time of communicating with individual TAs, and made it unnecessary to wait for a response -- if comments weren't there by the deadline, too bad. What I saw as one problem with this approach was that comments and analyses were regularly being made by TAs whose appointments had nothing at all to do with the subject matter. As an example (not representing any actual particular occurrence), a TA whose expertise was, say, legal matters or publicity would review (for technical content) an article on phased arrays. As far as I could tell, their reviews were weighted equally to those from people who really understood the topic. In any case, the one or few reviews from knowledgeable people were generally lost in the noise. I don't know if this is the method still being used -- I resigned my TA appointment several years ago when it became apparent that I was no longer able to make any substantial contribution. I know of at least a couple of very knowledgeable people who have done likewise. This is a shame, because they're perfectly willing to provide free technical assistance, yet the ARRL doesn't seem able to find a way to take advantage of it. I'm not sure they've ever solved the problem of editors who don't understand the material modifying it in such a way as to make it no longer true. In all cases but one when this happened to me, I was able to correct the problems before publication. In one case, however, I wasn't given enough time to correct the numerous misinterpretations, invalid "explanations", and other seriously wrong modifications made by the editor and had to pull the article(*). Several extremely capable people I know, however, have had serious errors introduced to their articles by the editor *after their final review*, so they didn't even get to see the errors until the article was published under their name. Most of these people will never write for QST again as a result. This is one of the reasons that QST has a smaller pool of knowledgeable and capable authors to draw from. So when you see a technically weak article in QST, the author might not be entirely at fault. (*) I want to make it clear that I'm very aware that my writing and communicating skills aren't all that great, and I really appreciate having an editor improve the style, clarity, and brevity of my writing, as well as questioning any weak or inconsistent arguments I've made. [A good editor would have cut half the words from the preceding sentence, and made it a lot clearer at the same time.] So I welcome editing. What I do object to is editing which changes the core meaning of the content and/or results in its being technically incorrect. Roy Lewallen, W7EL |
Supposed comparison of Mobile HF Antennas in November QST
|
Supposed comparison of Mobile HF Antennas in November QST
"Michael Coslo" wrote in message I've been pleased so far. I worked some CA QSO party from the middle of PA on 20 meters with it, and all I could hear I could work (100 watts) While you can not work a station if you can not hear it, that is no way to compair an antenna. I have an off center fed antenna up 45 feet and a tribander up 57 feet. I can hear more on the beam than I can on the OCF . I can probably work all I can hear on either antenna. It is I just hear beter on the beam on the bands it is cut for. |
Supposed comparison of Mobile HF Antennas in November QST
On Oct 29, 11:51 am, Michael Coslo wrote:
It is narrow, but that's only been a big problem on 80. I've seen some on 80 where the people would tune them at driving speeds because the leaning back of the antenna would detune far enough to be a problem. :/ They didn't have a wide enough bandwidth to really get both positions with a good match. Good performing antenna though. How well mine does depends on the path, distance, etc.. On 40m, mine will beat my dipole which is at 35-40 ft on paths over about 1000 miles or so late at night. IE: Houston to Florida. We tested that many times to make sure it was not a fluke. I have no trouble on 80, but it also varies with time of day, distance. It's probably at it's worst real early in the evening to close NVIS range stations. But as it gets later, it will usually get better and better once the band gets stable and stretches out a bit. As usual, the longer the path, the better it might do vs a med height dipole. But I'm often pretty strong even to NVIS range stations. Not uncommon to be over S 9.. Sometimes 10-20 over.. Course, all the guys on dipoles might be hitting them at 30-40 over.. :/ But no problem talking. And I've never run an amp mobile.. Just 100w.. MK |
Supposed comparison of Mobile HF Antennas in November QST
John Ferrell wrote:
Last year I purchased a radio especially to go mobile. I have yet to find an acceptable mobile HF antenna to use on my Chrysler Minivan. I am beginning to believe that there are no acceptable solutions to the problem as I define it. Then you need to change your definitions, John, -I mean that in a friendly way. 8^) Too often, too many time, we expect some sort of perfection. It isn't going to happen. Mobile HF antennas are just not as efficient as a "good" land based antenna. I'll leave the definition of good up to everyone, suffice that the mobile antenna isn't as efficient as most. That being said, you can have a lot of fun on HF mobile and can talk around the world. Why let the needed compromises keep you from that? If you are wanting to squeeze the last little bit of efficiency out of your antenna, I would suggest a mid-loaded antenna with a capacity hat on top somewhere (some say directly on top, but you'll have to put up with a lot of wind loading) Use a loading coil that has as high a Q as you can get, and bond everything you can in the van - doors, hood, fenders, frame components, engine, radiator, exhaust system - and in multiple places. You want as much ground plane as possible, even if at best you don't get much. Further, I have concluded that ALL MOBILE HF installations are poor compared to a dipole five feet off the ground, some are just worse than others. I don't think that is an exact comparison, but the question is so what? Get as good as you can afford/want to put in th elabor, and go have fun The article simply sheds some light on the practical issues one encounters with popular alternatives. I think an auto tuner with whatever whip length one can tolerate is the best one can do with a Chrysler Minivan. Don't agree there. You could use a bug catcher or screwdriver and be better than that. Modeling programs do not consider the radiation from the loading coils but field measurements do. Tuner losses can be estimated from the software in the Arrl Antenna Books. If you can write a better article for QST, please do so. But please remember, most of us don't choose the ethical we drive because of its ability to carry a less bad radio antenna! I'm driving a Suzuki Vitara -maybe the smallest SUV around. Yet I have an antenna that allows me to have a lot of fun and yes it does get some stares. If I put a football team pennant on it, everyone thinks I'm kewl. AS for writing an article for QST, I don't think its a bad idea at all to be critical of an article that could have been written better. That I didn't write one does not mean that those who do have free reign to write a poor one if they like. - 73 de Mike KB3EIA - |
Supposed comparison of Mobile HF Antennas in November QST
Ralph Mowery wrote:
"Michael Coslo" wrote in message I've been pleased so far. I worked some CA QSO party from the middle of PA on 20 meters with it, and all I could hear I could work (100 watts) While you can not work a station if you can not hear it, that is no way to compair an antenna. I have an off center fed antenna up 45 feet and a tribander up 57 feet. I can hear more on the beam than I can on the OCF . I can probably work all I can hear on either antenna. It is I just hear beter on the beam on the bands it is cut for. Its not meant to be a definitive test of the antenna, but I have used some antennas where that was not the case, Hopefully this is not the sort of group where one has to take their antenna to a range before they are allowed to comment on it, good or bad. I used it, and didn't have trouble making contacts. Others can determine if it works or not according to their own guidelines. - 73 de Mike KB3EIA - |
Supposed comparison of Mobile HF Antennas in November QST
Hello Roy...
The definition of a committee is a dark alley down which you lead ideas so that you can strangle them. My impression is that the QST editorial process is riddled with committees, and they're quite effective (hi). I've given up writing for them due to the many problems you recounted - I don't say forever, but for the time being. I'm very tired of objections that don't make any real sense, while seeing this kind of article (which also makes no real sense) published as is. QST used to be a respected technical journal. It's grown inbred, inflexible, inaccurate and inconsistent. It no longer really serves the amateur community - it seems to largely serve itself. Maybe a (metaphorical) bomb will go off or someone will start a revolution and it'll change. Not likely, but maybe. Perhaps a group of (former) writers could prepare a joint "declaration of limited support" to present directly to the ARRL brass (bypassing the editors) to call for action/changes. Nice to run into you here. Best regards - Robert Victor VA2ERY Roy Lewallen wrote: QST editors can't be expected to be experts on all the topics they have to deal with. Over the years, they've dealt with the problem in various ways. One was to establish a pool of "Technical Advisors" -- volunteers who had particular expertise in various areas. Some manuscripts being considered for publication were sent to the appropriate TAs for comments and review. This practice slowly died out, but I don't know why. I suspect it was because the editors seldom had the time for this step in the process due to erratic scheduling. Eventually, they adopted a solution which was easy on the editors and their schedules: post the proposed articles to a restricted web site where the TAs could review them and leave comments. This saved the time of communicating with individual TAs, and made it unnecessary to wait for a response -- Roy Lewallen, W7EL |
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