Re: [Elecraft] Antenna Tuner versus Antenna Analizer ?
Thanks to everyone that replied to my subject email. All the info helped cleared up some of my confusion. Paul (73) KD8 HWP - Original Message - From: "Paul Maruna" <[EMAIL PROTECTED]> To: Sent: Wednesday, September 10, 2008 5:46 PM Subject: [Elecraft] Antenna Tuner versus Antenna Analizer ? I bought a buddipole antenna system and I want to get one of the subject units but I don't know the difference between them, and what each one does, and which one will help me with the setup with my K3 and my antenna system ? When I bought my K3 I also bought a KAT3 which I believe is an antenna tuner for the K3 -- Will this do the same thing to match the antenna to the K3, or am I better off getting another unit like a LDG Z-100 or an LDG AT-200 Pro or something else like one of the MFJ units ? Where does the "baluns" come into this play with either unit ? I am just a Technician class and am studying for the General class and I have not built the K3 that I have yet, and all this antenna stuff is pretty confusing. Can anyone help please ? Thank you, Paul (73) KD8HWP ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Antenna Tuner versus Antenna Analizer ?
Hi Paul: I bought a buddipole antenna system and I want to get one of the subject units but I don't know the difference between them, and what each one does, and which one will help me with the setup with my K3 and my antenna system ? Actually, BOTH devices may help you. But, at this point, possibly the Antenna Analyzer might help most... IF you understand what it does. Using an Antenna Analyzer will allow you to adjust your antenna(s) such that they will present (to your transmitter) the best and most efficient LOAD for a given band. The closer the LOAD IMPEDANCE of the antenna (and feedline) are to matching the output impedance of your transmitter, the more efficient will be the transfer of RF power from the TX to the antenna. The Antenna Analyzer is NOT a 'tuning device', in that it MAKES these adjustments! It only allows you to SEE the effect of adjustments you make to the antenna as you attempt to optimize the antenna's performance. On the other hand, an Antenna Tuner (ATU) is a device which you DO adjust in an effort to compensate for mismatched presented by the antenna/coax combination to the transmitter. This device will NOT change the SWR on the coax between itself and the antenna, BUT it can (often) create an offsetting set of conditions which will make the mismatch APPEAR TO THE TRANSMITTER is if the transmitter is seeing a near-perfect load impedance, even though the real loaf from the antenna/feedline may be much different from 'perfect'. When I bought my K3 I also bought a KAT3 which I believe is an antenna tuner for the K3 -- Will this do the same thing to match the antenna to the K3, or am I better off getting another unit like a LDG Z-100 or an LDG AT-200 Pro or something else like one of the MFJ units ? The KAT3 is the 'antenna tuner' of which I wrote above. It is NOT 'the perfect answer' to all antenna mismatch (SWR) problems. But it CAN compensate for some of the smaller ones and allow your K3 to operate rather efficiently into a non-perfect load (from the antenna/coax combination). You FIRST would want to try to optimize your antenna/coax combination such that it presents to the TX a LOAD which is as close as possible to the desired 50 Ohms (which is what most modern ham transmitters wish to see). Once you have gotten the load from the antenna/coax as close to 50 Ohms as you can reasonably expect to achieve, THEN, you can use the antenna tuner (KAT3 or other similar device) to provide the final compensation between the antenna/coax and the TX so the TX 'sees' its desired 50 Ohm load on the desired band and frequency. If your antenna/coax combination cannot present a decent load to the TX, the antenna tuner will ATTEMPT to compensate so the TX still thinks it's seeing a workable load impedance. But most ATUs have their limits to he range of load mismatch for which they can compensate... often they cannot make a silk purse from a sow's ear!!! This having been said... and assuming the ATU is either installed INSIDE the radio, or immediately outside the radio in the coax line, you must understand that the ONLY compensation which the ATU can provide is to the TRANSMITTER and any short length of coax between the ATU and the TX. IT DOES NOT CHANGE THE LOAD (SWR) WHICH IS STILL PRESENT ON THE COAX GOING TO THE ANTENNA! As a result, if your antenna is badly non-resonant, and presents a horrid load to the TX, using an ATU may(!) be able to compensate to the point that the TX 'thinks' is sees a resonant antenna, BUT the truth of the matter is that the TX is the only one being 'fooled'... the antenna/coax still has the same poor load impedance it originally presented, and it will be just as INefficient as it was before the ATU was introduced into the equation. The ATU does NOTHING to change the real matching at the antenna. YOU must make those changes yourself BEFORE you try to use the antenna. Where does the "baluns" come into this play with either unit? A balun (BALanced-to-UNbalanced) impedance transformer will NOT come into play in the scenario you write about, above. The Buddipole does NOT require an impedance matching transformer, and neither does the coax between it and your K3. Sometimes a 1:1 impedance ratio balun is used in an effort to keep RF which can appear on the OUTSIDE of the feedline coax from being radiated. In this case, the 1:1 balun (or a similar in-line coaxial RF choke) will be installed AT the feedpoint of the antenna. In this manner, RF is 'choked' off of the outside of the coax and prevented from being radiated, thus keeping the feed- line from acting as a 'radiating' part of the antenna system. I am just a Technician class and am studying for the General class and I have not built the K3 that I have yet, and all this antenna stuff is pretty confusing. Hope this helps. 73, Tom HammondN0SS ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the lis
Re: [Elecraft] Antenna Tuner versus Antenna Analizer ?
Hi Paul, Just to expand slightly on this one aspect of your question. The term "balun" is a contraction of "balanced-unbalanced". It's a device for connecting a balanced feedline to an unbalanced one. Most transceivers these days are designed to connect to a 50 ohm coaxial cable (such as RG-8, RG-58, etc.). Coaxial cable is an unbalanced feedline, since one side (the shield) is connected to ground. Unfortunately, coaxial cable will usually have a higher loss than a balanced feedline ("ladder line"). The purpose of a balun is to efficiently couple the balanced feedline to the unbalanced coax that connects to your rig. Many hams do not use baluns. They will run coax from the rig all the way to the feedpoint of the antenna. This is especially true when the antenna is resonant (that is, a full half-wave on the band you're operating). Many commercial antennas are designed for connection directly to 50 ohm coax, without an intervening balun. 73, Dave KQ3T Paul Maruna wrote: ...Where does the "baluns" come into this play with either unit ? ... Thank you, Paul (73) KD8HWP ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Antenna Tuner versus Antenna Analizer ?
Paul, Since you find antennas confusing at this point, you may want to look at the Antenna article on my website http://w3fpr.qrpradio.com. It tells about antenna concepts in layman's language as much as possible, and no math. Second comment is that you may want a wire antenna instead of the Buddypole for your home station. A half wave dipole at the lowest frequency of interest fed with ladder line will receive and radiate much better than the Buddypole in most situations. One cannot defeat the laws of physics. An antenna shorter than 1/2 wavelength (1/4 wavelength for verticals with a good ground system) will be inefficient by comparison - don't be fooled by the advertising hype - a full size G5RV antenna is just not as efficient on 80 meters as a 135 foot dipole. The Buddypole *is* a very nice convenient antenna for portable work and likely more efficient than most portable antennas, but for the home station, you can likely do better with just wire. The KAT3 with a 1:1 balun or 4:1 balun will provide all the tuning range normally needed to tune a wire antenna with ladder line, you should not need a separate tuner - and the KAT3 will remember its settings for each band for you - no knob twisting when changing bands. 73, Don W3FPR Paul Maruna wrote: I bought a buddipole antenna system and I want to get one of the subject units but I don't know the difference between them, and what each one does, and which one will help me with the setup with my K3 and my antenna system ? When I bought my K3 I also bought a KAT3 which I believe is an antenna tuner for the K3 -- Will this do the same thing to match the antenna to the K3, or am I better off getting another unit like a LDG Z-100 or an LDG AT-200 Pro or something else like one of the MFJ units ? Where does the "baluns" come into this play with either unit ? I am just a Technician class and am studying for the General class and I have not built the K3 that I have yet, and all this antenna stuff is pretty confusing. Can anyone help please ? Thank you, Paul (73) KD8HWP ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.6.19/1664 - Release Date: 9/10/2008 6:00 AM ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Antenna Tuner versus Antenna Analizer ?
Paul, As an addendum to the excellent summary by Bruce - W8FU, let me add that the Buddipole antennas are designed to match a 50 ohm coax feeder pretty well. They are off-center fed to get near to the correct 50 ohm impedance. So if you use the K3 antenna tuner and the Buddipole you won't have too much loss in the coax line. However, the Buddipole is a short dipole and as such not a particularly efficient radiator. You may find that with the 100 watts output of the K3 you will do very well with the Buddipole. But at some later stage of your career you may want to have a longer piece of wire. A non-resonant doublet of 66ft or more fed at the center with 450 ohm ladder line is a good minimum. BUT, don't get rid of your Buddipole. It is great for Field Day. Good luck and 73, Oliver Johns - W6ODJ On 10 Sep 2008, at 3:46 PM, Paul Maruna wrote: I bought a buddipole antenna system and I want to get one of the subject units but I don't know the difference between them, and what each one does, and which one will help me with the setup with my K3 and my antenna system ? When I bought my K3 I also bought a KAT3 which I believe is an antenna tuner for the K3 -- Will this do the same thing to match the antenna to the K3, or am I better off getting another unit like a LDG Z-100 or an LDG AT-200 Pro or something else like one of the MFJ units ? Where does the "baluns" come into this play with either unit ? I am just a Technician class and am studying for the General class and I have not built the K3 that I have yet, and all this antenna stuff is pretty confusing. Can anyone help please ? Thank you, Paul (73) KD8HWP ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] Antenna Tuner versus Antenna Analizer ?
I am not totally sure about your question but if you are wondering what the difference is between an antenna analyzer and an antenna tuner, basically the analyzer is an instrument to determine the characteristic impedance of the antenna at the antenna terminals or the characteristic impedance of the antenna system, including the feed line, at the end of the feed line. It can also measure a number of other electrical characteristics and is a very useful instrument but I think it is probably in excess of your needs at this stage of your hand career. And antenna tuner on the other hand is a device which will attempt to transform the impedance presented to it at the end of the feed line from the antenna so that it matches the expected load impedance of your radio which is 50 ohms. The resulting transformation or "match" performed by the antenna tuner should result in a 1:1 SWR as seen by the final of your radio. When there is a low SWR as seen by the final of your radio there should be a maximum transfer of RF power from your radio to the antenna so that it can be radiated as a signal. However, if there is an extreme impedance mismatch between the end of the feed line and the 50 ohms expected by your radio there can be problems as noted below. I think you will find that the K-3 antenna tuner is a very good one and will tune a wide range of antennas. Since you already have it, I suggest you try it first with your antenna. If for some reason it does not work you could always try a different, external tuner. But if the antenna cannot be tuned with the built-in K-3 tuner I think you would be well advised to consider a different antenna. Just because you may be able to reduce the SWR presented to the radio by using a tuner does not mean you have an efficient system or that most of your RF will actually be radiated rather than simply dissipated in the tuner. If the terminal match between the antenna and feedline is very unfavorable, while the tuner may be able to transform the resulting SWR presented to the radio enough to allow the final to run at full power you may find that much of the power is being dissipated in the antenna tuner as heat rather than being radiated by the antenna. If for example you are running 100 W from the transmitter but 80 of those watts are being dissipated in the tuner because of a very unfavorable antenna impedance, there won't be much RF power left to actually reach and be radiated by the antenna. So, I would try the K-3 antenna tuner first. Chances are it will do the job. If not you may want to consider a better antenna before you start looking for external antenna tuners. Frankly, the only time I would consider an external tuner is if I were using a balanced feed line and even then I might choose a 4 to 1 current balin at the output of the radio instead of a balanced antenna tuner. Another situation calling for an external tuner might be if you are using an amplifier following the K-3 and the impedance presented by the antenna system cannot be handled by tuning the amplifier. Good luck with your license upgrade and your new K-3. Bruce-W8FU -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Maruna Sent: Wednesday, September 10, 2008 6:47 PM To: elecraft@mailman.qth.net Subject: [Elecraft] Antenna Tuner versus Antenna Analizer ? I bought a buddipole antenna system and I want to get one of the subject units but I don't know the difference between them, and what each one does, and which one will help me with the setup with my K3 and my antenna system ? When I bought my K3 I also bought a KAT3 which I believe is an antenna tuner for the K3 -- Will this do the same thing to match the antenna to the K3, or am I better off getting another unit like a LDG Z-100 or an LDG AT-200 Pro or something else like one of the MFJ units ? Where does the "baluns" come into this play with either unit ? I am just a Technician class and am studying for the General class and I have not built the K3 that I have yet, and all this antenna stuff is pretty confusing. Can anyone help please ? Thank you, Paul (73) KD8HWP ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com