Ask Dave Episode 1: Antenna Analyzers
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- เผยแพร่เมื่อ 10 มิ.ย. 2015
- New series! Ask your questions about ham radio. Designed especially for new hams. This week's episode explores antenna analyzers and things you can do with them, including measuring coax loss, distance to fault (coax length), velocity factor, and trimming a six-meter (52 MHz) dipole for lowest SWR. Ask your questions at www.ke0og.net/ask-dave.
- วิทยาศาสตร์และเทคโนโลยี
Hi Dave. I hope you do not mind, but you have become one of my "Elmers" ! I left the British Royal Navy (Submarine Service) in 1991. Having been a Radio Op in the Navy I always wanted to get involved in Amateur Radio. Well the day arrived, a little delayed with life, but I am currently studying for my Foundation Lic., in the UK, and you, along with others, have become a shining light in furthering my education in Propogation, spectrum analysis, RFI, antennas and general very useful info on all else. I would like to take this opportunity to thank you for your presence out there for us all. Thank you so much. Keep it up and the best of health to you Mr Casler Sir. 73.
Dave you are an excellent teacher, Elmer and overall guru. You have a calmative inflection but what you have to say is so informative, I learn all the while. Thank you sir!
Hi Dave hope all is well with you and your family question, I'm having all hell trying to get my antenna to match 50ohms sometimes it gets as high as 30 and that's it with a good swr it's a diy 4 element yagi on the 11 meter band any support will be greatly appreciated
Mᕦ⊙෴⊙ᕤᕦ༼✩ل͜✩༽ᕤ
I feel tremendous joy when I watch your shows. Thanks for being a great teacher Dave!
I've ridden the train a few times and enjoy it as much as the first time, beautiful area. Renewing my knowledge base after a 10 year absence from radio, thanks for the helpful videos.
Well done! I appreciate the brief overview followed by the hands on "how to do it". I look forward to each future episode.
Thanks Dave! Every time I get discouraged I find myself right back on your home page or on on your Utube site. There’s always encouragement and positive answers from you. BTW Anyone who knows Train Lines are great at details. After a visit at Mayo Clinic and having a very very serious operation with my being heart removed from my chest for 10 hours, I left a high pressure job and took up model trains. What great history there is in the Railroads of America! And the World! 73’s. Wesley KC5FTT
Thanks for a very clear explanation and demonstration David. I’m not an r.f. expert but your videos sure help me get a feel for the practical aspects and the adjustment sensitivities at these frequencies. Your a fantastic teacher - keep up the great work and keep well.
Nice video Dave, Been a ham for 40 years and learned a lot from that one. Keep 'em coming. 73.
Thank you so much for this video.
I really like that you brought up the drop in resistance due to non-optimal height, and this is an excellent video to put it in, since people who have just gotten their new, shiny antenna analyzers are going to be wondering why they can't achieve an 1:1 SWR no matter how much they adjust the length.
On point, well paced, and informative, as always.
Dave, Thanks for your video! I am a new ham and I am building my first antenna and this gave me some useful information. Also on a side-note thanks for the picture of the Silverton train station. Brings back memories of riding that train as a kid. I Look forward to more of your videos on everything Ham
***** You're welcome!
Dave, as a very new operator, I can't tell you how much I appreciate your videos and how invaluable they have been to me! I am trying to consume as much info as possible and subscribing to your channel has been the top of my "education". If you ever get down here, would love to buy you a cup of coffee! Thank you and 73! ka0rsn (Pagosa Springs)
+Gear Hammer Thanks! I'm glad you found the videos useful!
Dave. Your instructional technique is superb. I learn so much from you & I'm very grateful. And I have no questions, dumb or otherwise, at the end of your vids. Thanks.
Thanks Dave for your Videos, I just passed my Tech and General License test today. I watched your training videos many times, a big help on clarification on many topics, Just want to let you know you helped this new Ham get some positive insight in your introducing me to this vaste hobby! 73!
Thanks for an excellent video! One of the best explanations I've seen on setting up and tuning an antenna. Not just what you are doing, but WHY you are doing each step. Great narration and camera work, too. Looking forward to viewing all of your other productions!
73 from Winnipeg, Canada
I love your videos. Very professional. First time I understood frequency and lengths. I finally found a good teacher.
Great video, David. Looking forward to more in the series!
Thanks for for taking the time to make the video and posting it Dave. I am about to have a loan on an MFJ analyzer and will in time buy my own. The task for this weekend is to fit a 6m inverted vee dipole onto my loft, (attic) and enjoy some of the sporadic E were enjoying in Europe. Your video is invaluable.
All the best & 73
2E0MIY (England)
I've been watching several of your well presented videos for sometime now. I like what I've seen and continually look for any new video presentation. The series you've created for new Ham radio operators is an ideal starting place to learn much of the in's and out's of Ham radio. I will continue to recommend your videos to anyone asking for a place to find great Ham radio operating instruction.
I've been using the latest digital mode since it was released by Joe Taylor in July of 2017. I would like to see a video you create giving an overview of the FT8 digital mode latest version 1.9.
Thanks so much for all you have done - Keep up the good work. K4KSW.
Excellent. Loved this first one. Will keep watching the rest of these videos on 'Ask Dave'. I learned a bit from these. Thanks.
You're an excellent presenter addressing exactly what radio amateurs need to know. Thank you/73 de SA5QED
Dave, I really liked this video. I have the same MFJ and it is about the most logical analyzer I have ever used. I love it. Excellent demonstration of it. And I must say, pretty good job of getting well inside the ball park on the first try.
Hello Dave. I got my first HAM license 10 years ago and have been looking for a source of easy to understand information ever since.
I joined a HAM club in hopes they would hold classes on topics of interest, but of course they didn’t. I like to use the analogy of asking someone what time it is, and they tell you how to build a Grandfather clock.
Your videos are what HAM club meeting SHOULD be about.... sharing information instead of the smug “Go learn it like I did!” attitude of so many HAMS.
Thanks Dave!
Excellent presentation. Good clarity and content.
I learned something new about analysers.
Thanks, cheers :-)
Thank you for the easy to follow instruction. I am a new Ham (no call sign yet) and appreciate the effort many experienced Hams put into videos like this. "73" North Central Idaho
+Ty Williams You're welcome!
.ca doug
Ved
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Vidoliser
Great timing! I bought the same MFJ antenna analyzer a while back off Ebay and need to check my new Myantennas EFHW 4010 location endfed. Your tutorial will help immensely along with the analyzer manual. Thanks again, Steve KZ5MSE
David your getting better and better,keep up the good work on your new platform!
worksmartpaul Thank you!
Excellent video tutorial. I'm borrowing an analyzer soon to use getting a new dipole tuned and in the air. This information will help a lot with that project. Down the track I plan to buy an analyzer, probably the current version of the very one you used here. Thanks David, and best wishes.
I'm a little late to the party with this one, but as a new qualified novice here in the UK, this video has taken away some of the confusion in terms of understanding simple antenna building. Thank you for your time....
Just subbed, I am taking my Technicians test in mid May during our Hamvention, watching all of your vids. Thank you for your time on YT
Good luck with your studies!
an excellent resource. thank you for taking the time.
Enjoyed the video. Thanks for sharing. I go near your area sometimes as a truck driver. route I take is moab, Monticello, Cortez. Usually take it when Wyoming I80 closes. Be safe up there as I know you get some crazy snow. 73's.
Nice start Dave. Great series.
Thanks Dave !! That's great video . God bless you for your initiative to help people.
excellent video and simply put for all to understand, well done
Hello Dave, I am KC4ZZE, this is what Ham radio is about, sharing experiences and knowledge to advance the art. Thank you for doing that. I would like to share an experience with you: I needed a way to rotate the hexbeam remotely 200 miles away from the shack using a RCA VH226E antenna rotator. I came up with a solution after giving it a lot of thought. I purchased a WIFI IR hub and manually programmed the hub training it with the VH226E’s RCA handheld remote control as an experiment. It worked! I can now rotate the hexbeam from my cell phone turning it North, East, West, and South controlling the VH226E Antenna Rotator from my android cell phone using the Tuya App. The IR hub is freely supported by the Tuya app. I watch from two remote cameras to see the inside rotator box and outside antenna rotator operate and turn as I use the Tuya app. The AC power to the inside RCA VH226E box is a manual switch on the side of the box. I set the switch to permanent on position and plugged into a Kasa AC outlet. Now I can rotate my antenna from any where in the world with WIFI connection.
David: Thank you for your series of videos. I'm new to HAM and your videos have been very informative.
Love your videos! Have learned more from you in watching 4-5 videos then anywhere else. THANK YOU
Good stuff Dave...! Down to Earth...Easy to understand. Thank you Dave!
Your videos are pure gold.
Awesome video, it answered a lot of my questions about antennas. Yes I have one of MFJ’s SWR meters and I’m learning to use it, that just gave me more knowledge as I am going to be building my own antennas
Hi Dave, excellent vid! I started the Ham process in Oct 2016, took the Tech exam on the 22nd and then the General on 8 Nov. I've been looking for solid Ham radio vids and am now a subscriber to yours. I'm getting the equipment over this winter and will be operational in early Spring 2017. Bought an IC-7300 and can't wait!
PS: My wife and I rode the Durango and Silverton back in Aug 1999, and then drove to Chama, NM, for the Cumbres and Toltec RR. Both were fantastic.
73,
Bob/ KD2MCH
Bob, welcome to the channel! 73
New to HAM ....thanks, I look forward to seeing many more of your videos.
You are a natural born teacher, sir! Thank you.
Murat from Turkey
+xlenau Thank you.
Dave, Great idea...You did great explaining the "J" Pole antenna...
just found your channel and looks to be answers to my questions. Thanks Dave.
Dave thank you. I don't make comments all the time. I can't believe I your first ask Dave. Been wanting to put loop for 40mts. Been off the air for sometime. At my age you have to keep things to a point of I can do it
73 KQ4CD
Thank you and one more subscriber. New to the hobby and studying for the UK foundation licence. Lockdown means no local clubs are open so books and YT are the main options open. Your channel will be playing a big role in my progress, thanks again
Nice start, Dave. You are an outstanding presenter. I’m a Colorado boy now displaced to the Pacific N W.
I find your videos to be very informative and easy to understand. Thank you.
Very well done and informative video. Nothing like watching an expert do it as they explaining in simple terms along the way.
Thanks, KE8FNA
Thank you and thank you. You do a great job helping newbies really understand.
Thank you for the information. As a new "ham", I enjoy learning new things. Keep up the good work! 73! KM4QFN Mike
Hi Dave, thanks for the photo at the end. I didn't know where you are. My wife and I are going to take a vacation/road trip and have that railroad on our plans. This will be in 2020. 73
's. Great video, I am new to this game:)
Dave, please ignore my question on extremely high db loss. I've chalked it up to the ignorance of a novice. I tried to measure coax loss with an antenna on the other end. Once I took the coax off the antenna my loss was .4 db. Am satisfied with that.
Hi Dave....I spent a few weeks out in your area....went to Pikes Peak...rode the Durango Silverton RR then drove from Colorado Springs to Bryce Canyon.......just totally amazing stopped at Ouray....we were able to get to stay inside the Bryce Canyon Park......the skies were incredible...I made this trip between my second and third years of law school as I knew I would seldom have the time or the money to do it again.
Nicely done instructional video! Thanks for sharing your knowledge.
Hi Dave, you've been great as far as answering questions I've asked so I thought I'd get back to you with a rather unconventional fix. I wrote a few days ago on how to remove "dirty" electricity from my rig....I'm using a Generac 800 watt generator.
A friend gave me the phone number of an engineering outfit....I called the number and the guy I needed to talk to was on vacation but the fellow on the phone told me to wrap the generator in aluminum foil.....that's right, aluminum foil. Well, I was ready to try anything and ridiculous as it sounds it worked. It cleaned up the RFI and sounded better than power from the power company does. I'm not kidding about that...the sound is better than I can get from house current. Now I need to figure out a way to make this work and not burn the generator up in the process. Thanks for your help.
-Pat KD9DST
Excellent video. I searched on antenna analyzer and this was first
I noticed you used the same kind of notepaper I do when I am in a hurry, lol. Building the antenna the way you did is very enlightening.
Great explanation Dave! My son (15 and learning for his HAM exam) understands what you are saying. Excellent job, (only the conversion of feet to meters makes him fuzzy) 73 Jan, the Netherlands
Nice tutorial. Even if you don't have an antenna analyzer but you have a radio and swr meter, it works too. You can use the analyzer if you don't have a radio to test the antenna.
Great video, Dave!
excellent teacher. i have got an insight of antennas. you have almost answered most of my questions
hello Dave . wondering does my dipole need to be 32ft .
Good video. Always learning.
Dave you are a great instructor!
Thank you! 73
Just got an old MFJ 269 and your video was very easy to understand. M0RMW
Many thanks Dave for your very helpful tutorial. Trent Saunders ZS5TC
You're welcome! I'm glad you find the videos helpful. 73, Dave
Best dipole video I have seen! David Byrd KN4BHS
great video Dave
Very useful - thanks Dave
Hi Dave. de w5kub. great video as all the others are. I love wire antennas, You can learn so much. Found one little blooper in this video. you called it an antenna tuner when you were hooking up the coax to test the dipole. lol. I do that all the time too. Looking forward to getting you back on Amateur Radio Roundtable when you have the time.
Hi Tom, good catch!
Hey, Dave. My 8010 efhw came with recommendations to put it up 20 feet in the middle and 6 ft up on the ends. 80 meters had a high SWR. So I then put the middle up around 57 feet...ends at about 5 ft, grounded just below box. Works great but power was off. I am barefooting. All bands. All below 2:1. So two counterpoises seemed to improve everything some, including the SWRs and power out. I live on near the East coast near Charleston. Have reaced Chechnia, Italy, Croatia., Arizona, Nebrasca with good reports so far. So, while barefooting, I guess that will do. I ordered a Signalink USB and am looking forward to doing some RTTY and digital stuff. Not a CW guy yet but working on that, too. Thanks for what you do! Gonna copy this to Kevin, too. 73
Hey Dave:
So excited to see this column! Another great topic and one I always have questions about.
1. When testing antenna wire length. I've heard that you can just crease the wire end and that will shorten the wire while testing before you cut it permanently. Is that the case and how much of a crease does it take? Say I want to build a dipole on 160 meters. My yard is way too small, can I do a series of 90 degree bends without that effecting the total length and performance of the antenna?
2. When designing an antenna. What determines if you need a balun, choke, etc. and what type 1:1, 4:1, etc. Why do they have those LC matching networks? How to choose the network type? Coils? Capacitance hats? Etc. (Might have answered my question with what I said below) Can't you just match the antenna by changing the length? Guess that would change the SWR?
3. In the video the analog ohms meter was showing 40 but the digital meter was showing R = 33. Are both those numbers the same, the analog part is just off?
3. Prob a dumb question, but does high SWR affect an antenna's ability to receive like it does on transmit?
4. A bit past the 15 min mark, in the video it's showing a 1.5 SWR and a R=32. You said the Impedance is a lil low because of the low antenna height. Is their a way to correct this so you have the 1.5 SWR and R=50. If so how would you correct it? How much does this effect performance by having the Impedance a bit low, but SWR spot on?
5. Is their a way to know how bad a 160 meter antenna would perform only 20 feet off the ground? What is the best way to design it to make up for the shortcomings of low mounting height or if I purchased a commercial dipole, how would I change its design?
6. Showing us how to design an antenna in EZNEC would be a fun video, using a simple off the shelf antenna for the inputs. That might help to understand/visualize how the software works better.
7. Say I design a ¼ wave 2 meter vertical antenna and have a off the shelf antenna. Something like a Diamond Antenna CP22E. Is their cheap/easy way to test the performance of each antenna? Like measuring it’s signal strength 100 feet away so I know what one performs better/goes further?
7. I have a Radiowavz EFH20 end fed half wave antenna. I mounted it to a steel pole. SWR was thru the roof. I put a piece of PVC around the steel pole and that seemed to fix it. I also have a 2 meter antenna on the same pole above it. How do I know if they are interacting with each other? SWR on both is good. But the 2 meter just doesn’t perform like it used to. If I take the end fed off it works great.
FYI: You might want to change the video title a bit so it’s more descriptive. For example, “understanding antenna analyzers - ask Dave video 1”. That way when people search in Google the video will show up more often in search results.
Thanks again for all your helpful videos!
Craig Mullins - KK6FFZ
Craig Mullins Hi Craig, lots of good questions! I'll try to address these in forthcoming videos. Also, in response to your suggestion, I made the title more descriptive.
If you change the horizontal dipole into an inverted V you can change the impermanence closer to 50 ohms by playing with the angle of the elements.
This is also a great review for an old ham like me 1965. WB7ORB
Great Video - Good production quality, well spoken and excellent info.
73 from North Idaho
thank you Dave very interesting I enjoyed it so much.
Great video!
Excellent!!! Thank you!
Great Instructor. I am about to take my Tech exam. This is the first time I have heard about placing the antenna 1/2 wave length above the ground. Where is the best place to find out more about this? Thank you for your dedication to Ham Radio!
Masterfully well done video, Dave. BTW MFJ bought a copy of the QCX case. I expect we will see them offer one from China soon enough.
Dave,this ask dave series is grea. thank you. w7utp
Great video about Antenna Analyzers and the height of dipoles does matter. Keep up the good work Dave Casler KE0OG. 73, WA6TWJ Dave Mauldin USA
Thanks Dave for your lectures they are very informative , great clarity and very informative , Keep doing the great work . Thanks Ivan K9dxc,Vu2dxc
Bravo, thank you!
Dave,
Ray N1MPD here from MPD Digital. Love your vids. One issue here though is your exposed coax. I know this was a temporary video but the only thing we don't warranty cable for is Water Infiltration. Leaving the end exposed to the elements OR depending on any PL-259 to keep water out of your feed lines is a recipe for disaster.
Cable assemblies should last 15-20 years or more, but we get a lot of business from folks who have to replace theirs after only a couple of years because they didn't seal the end connecting to the antenna.
Absolutely true!
There are many new analyzers out there now. You used to have only a couple of choices. Now there are all kinds of choices out there. Including these nano-vna units.
The MFJ does several other handy functions though. Including using it as a sugnal generator, frequency counter, measuring inductance and capacitance at different frequencies. Etc..
Thank you Dave you have a lot of great information out their for someone like myself who is new to the hobby. Thank you KG5PTE
Thanks a lot Dave.
I have been there very cool. Also Have found the geocache there.
Dave, an easy way to eliminate guess work and determine how much to add or cut from a dipole is to divide the frequency where it is initially found to be resonate into 468 and then subtract or add it from/to the DESIRED frequency divided into 468.
For example, if the initial measurement indicates resonance at 53.598 and the desired frequency is 50.125, divide 468 by 53.595. Result is 8.732 feet (which may or may not be the ACTUAL physical length). Then divide 468 by 50.125 which equals 9.337 feet. Subtract 8.732 from 9.337 equals .605 feet or 7.26 (7 1/4) inches. So add 3 5/8 inches (half of 7 1/4) each end and measure again. It should now be resonate at 50.125 MHz (National 6 meter calling frequency)..
Just a hint you may already know.
Yes, but I'd still leave a little extra length. I once cut a dipole in the manner you mentioned, and it ended up a little too short. So leave a little extra play with after the cut.
@@davecasler Interesting you should say that. It's always worked for me. However, I don't actually "cut" the wire. I wrap it back on itself in case I did have to lengthen it. But in over 40 years, I've never had to.
Great videos, just found you. Thank you very much for your service and help with your well produced tutorials and discussion. N0LKC
Love the video, Dave. Thanks for another informative and easy to follow guide. Have you ridden the train that comes through there? Where does it go?
Hi very good video . thanks . looks a very nice place where you live , must have flown over there so many time didnt know it was there , next time will give you a wave . keep the info vids coming . 73 thanks
Great video Dave! Would like to see same video for a monopole antenna in the 27 MHz band.
The new NanoVNA make the MFJ equipment look like junk.
The NanoVNA is priced far below any of the previous analyzers and it is very good, according to reviews I've seen (for example in QST as well as on YT).
The new integrated circuits have created a revolution in the antenna analyzer market.
A good analyzer can be very educational to show you exactly how your antenna looks to your transmitter and you can evaluate other components too, like coils, capacitors, dummy loads & matching networks.
For the ham who wants to go a little beyond rag chewing, a good antenna analyzer is a lot of fun.
.
Dave just developed a dipole exactly the way I've been doing for decades; more recently I've been using the mfj259.
I got one of those cheap Chinese antenna analysiser. I was unhappy with the instructions. I got hold of the MFJ instructions. I was happily surprised that by using those instructions I could do everything the MFJ Instructions covered. I guess the old gird dip meter can reside inside to measure coils. thanks for the video. KD5KZL 73
Are automatic antenna tuners worth the money?
Excellent, clear exposition. Could have made the point that the length measurments relate to half a wavelength (half wave dipole).
Thank you!