Ask Dave Episode 1: Antenna Analyzers

[@paulhastings3109]

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

[@120730amm]

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.

[@Bxcowboy]

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!

[@philipgreene2172]

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

[@stevenlsmith18738]

Mᕦ⁠⊙⁠෴⁠⊙⁠ᕤᕦ⁠༼⁠✩⁠ل͜⁠✩⁠༽⁠ᕤ

[@EdGrasmann]

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.

[@ganjajoe2566]

I feel tremendous joy when I watch your shows. Thanks for being a great teacher Dave!

[@rodchisholm4790]

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.

[@hypnosiscenternyc]

I love your videos. Very professional. First time I understood frequency and lengths. I finally found a good teacher.

[@gearhammer915]

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)

[@davecasler]

+Gear Hammer Thanks! I'm glad you found the videos useful!

[@terrycrissman7392]

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.

[@Snarky_Radio]

Nice video Dave, Been a ham for 40 years and learned a lot from that one. Keep 'em coming. 73.

[@jimguelde4068]

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!

[@FirstWizardZorander]

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.

[@wesleykicker4996]

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

[@tywilliams7780]

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

[@davecasler]

+Ty Williams You're welcome!

[@arnoldparkin8807]

.ca doug

[@arnoldparkin8807]

Ved oliser

[@arnoldparkin8807]

Vidoliser

[@ejdiii333]

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!

[@dr07828]

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.

[@worksmartpaul]

David your getting better and better,keep up the good work on your new platform!

[@davecasler]

worksmartpaul Thank you!

[@DucatiMTS1200]

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.

[@dcmsr5141]

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

[@davecasler]

Good luck with your studies!

You're an excellent presenter addressing exactly what radio amateurs need to know. Thank you/73 de SA5QED

[@thenar]

Nice start, Dave. You are an outstanding presenter. I’m a Colorado boy now displaced to the Pacific N W.

[@paulbillingham4594]

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)

[@davidobryan8041]

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

[@davecasler]

***** You're welcome!

[@theoldhobbit3640]

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....

[@bennyfernandez5714]

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.

[@xlenau]

You are a natural born teacher, sir! Thank you. Murat from Turkey

[@davecasler]

+xlenau Thank you.

[@timforrestcet35]

Good stuff Dave...! Down to Earth...Easy to understand. Thank you Dave!

[@michaeledmonds3218]

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

[@tommywalls1167]

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.

[@920colt]

Love your videos! Have learned more from you in watching 4-5 videos then anywhere else. THANK YOU

[@walterwinnipeg7350]

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

[@patrickslevin6424]

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

[@rvnmedic1968]

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

[@davecasler]

Bob, welcome to the channel! 73

[@gregorgman]

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:)

[@1974longhair]

Dave, I like the new series. You told us that we didn't need an antenna analyzer but didn't show us how to adjust an antenna without one. I'm a new ham and don't want to throw a couple hundred bucks at one just yet but would like to get on some hf bands.

[@davecasler]

1974longhair I mentioned it very briefly, but I'll give a more complete method in an upcoming video. Thanks for your question!

[@JLSoftware]

1974longhair There are formulas that you use, given the frequency, that tells you the length of antenna. He did that in the video.

[@davecasler]

1974longhair See "About Dave Episode 5," which directly addresses your question. 73, Dave

[@loft306]

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

[@patrickslevin6424]

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.

[@lesnorton4151]

excellent video and simply put for all to understand, well done

[@utkf16]

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

[@aleneskikalashnikova4570]

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.

[@davemitchell116]

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.

[@davecasler]

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.

[@davemitchell116]

@@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.

[@CraigMullins1]

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

[@davecasler]

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.

[@1BigOldBear]

I LIKE the way you did this video . GREAT Question: You and others, including "Crash Course" all show how to PROGRAM an HT, especially the Baofeng HT's, BUT, nobody explains or show how to ACTUALLY USE one. HOW to get or grab a signal and ACTUALLY USE the radio. All programmed, all charged, have license, now - HOW DO I "USE" it - PLEASE Please do a video on "HOW TO USE" a baofeng, once programmed and ready. - PLEASE.!!!

[@janwansink]

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

[@philippedecamp7558]

Thanks Dave !! That's great video . God bless you for your initiative to help people.

[@adelarsen9776]

Excellent presentation. Good clarity and content. I learned something new about analysers. Thanks, cheers :-)

[@VNeshyba]

Well done! I appreciate the brief overview followed by the hands on "how to do it". I look forward to each future episode.

[@jack002tuber]

Excellent video. I searched on antenna analyzer and this was first

[@561ENTERPRISE]

just found your channel and looks to be answers to my questions. Thanks Dave.

[@mikerey02]

Excellent. Loved this first one. Will keep watching the rest of these videos on 'Ask Dave'. I learned a bit from these. Thanks.

[@robertbluni9373]

David: Thank you for your series of videos. I'm new to HAM and your videos have been very informative.

[@Usacoax]

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.

[@davecasler]

Absolutely true!

[@CharlieTechie]

Very well done and informative video. Nothing like watching an expert do it as they explaining in simple terms along the way. Thanks, KE8FNA

[@davidbyrd5065]

Best dipole video I have seen! David Byrd KN4BHS

[@rogerwilliams1597]

Just got an old MFJ 269 and your video was very easy to understand. M0RMW

[@AussieMark909]

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.

[@thenar]

Nice start Dave. Great series.

[@larrybleigh8295]

Dave, Great idea...You did great explaining the "J" Pole antenna...

[@mihaifelseghi]

Your videos are pure gold.

[@patriot9455]

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.

[@jimself1954]

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

[@francismcclaughry3794]

I have just been told I can order one of these I just wonder about the battries should I order the nih batteries for it. I have never had one of these.? I must say your vidioes are a good learning curve.

[@infoaffiliatemagic]

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.

[@johnpatterson6205]

I find your videos to be very informative and easy to understand. Thank you.

[@joshuakatumba6644]

excellent teacher. i have got an insight of antennas. you have almost answered most of my questions

[@rickyn420]

hello Dave . wondering does my dipole need to be 32ft .

[@radman999]

Great video, David. Looking forward to more in the series!

[@schoocg]

Thank you and thank you. You do a great job helping newbies really understand.

[@DEVES4]

New to HAM ....thanks, I look forward to seeing many more of your videos.

[@bassplayer3974]

Thank you not a ham just interesting stuff look forward to browsing your videos . Wish I paid attention when helped my dad do this as a child. close to ground you tune a little higher or lowerr on band can't remember , once up you tune by adjusting the middle height. And yes its was a lot of adjust nipping to radio shack back down adjusting lol especially low bands seemed to have a narrower sweet spot.

[@AlexCausey]

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.

[@RevGunn-jq3cq]

Dave you are a great instructor!

[@davecasler]

Thank you! 73

[@clems6989]

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..

[@JosephLorentzen]

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

[@6700rra]

Are automatic antenna tuners worth the money?

[@68cristian]

an excellent resource. thank you for taking the time.

[@billrobie5134]

Nicely done instructional video! Thanks for sharing your knowledge.

[@MarkRose1337]

So I have a few questions! I don't yet have a ham license, so I think that qualifies me as a beginner :) 1. How do hams find each other? With so many frequencies available, how does it work? 2. I live in an apartment with no roof or ground access, but I do have a fairly large balcony, about 5 m long. My view faces ENE over a populated area, with at least a mile before the first building blocking line of site. What useful options are available to me? 3. Long distance 802.11 interests me. I've seen some incredible long distance shots done. What are the rules when using ham privileges to transmit at higher watts in the lower channels where ham radio is a secondary user? Does transmitting at ham-permissible watts prohibit the use of WPA2 or even using HTTPS on an open connection?

[@davecasler]

Mark Rose Hi Mark, good questions. I'll try to address these in an upcoming video. Re #3, yes, you can use those lower channels. However, on ham radio, we can't encrypt things because everything needs to be in the open. This may preclude https. This is an area I don't know much about - I'll have to ask around. 73!

[@CraigMullins1]

Mark Rose I live in Pleasanton and we are working on setting up a city wide mesh network. ARRL back issues have quite a few articles on the subject. Some people say HTTPS & WPA2 is fine, some don't. I'd love the FCC to give us clarification. Still trying to find some good antennas to hook to my Bullet M2

[@janetwinslow2039]

A nice clear explanation. If you raise that 6m antenna to optimum height, as you say the resistance will rise to closer to 50 ohms and the SWR will fall. But will the length have to be readjusted?

[@DradePhotography]

Thanks Dave for your lectures they are very informative , great clarity and very informative , Keep doing the great work . Thanks Ivan K9dxc,Vu2dxc

[@nontimebomala2267]

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.

[@w5kub]

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.

[@davecasler]

Hi Tom, good catch!

[@bradallen1832]

Why is ground connected to half the antenna? (Wouldn't that tend to ground out the air and/or the radio waves?) Wouldn't it be better to have the core signal wire connected to a whole wavelength antenna piece? Would it be better to have twice the length of antenna? Would it be better to have a whole wavelength connected to the core and the insulation connected in a different orientation such as vertical perpendicular right angle or some other similar concept? Lots of questions. What physics should I study so I can figure that out for myself?

[@davecasler]

RF behaves very differently from DC. It's possible for parts (or all) of an antenna to be at DC ground but still radiate RF well.

[@gort400]

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!

[@davidmauldin6615]

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

[@peterjones3245]

Excellent, clear exposition. Could have made the point that the length measurments relate to half a wavelength (half wave dipole).

[@cam-man7350]

Many thanks Dave for your very helpful tutorial. Trent Saunders ZS5TC

[@davecasler]

You're welcome! I'm glad you find the videos helpful. 73, Dave

[@pipedreams57]

I just bought one of the Uniden 980 Bearcat CB/SSB radios. I have a ProCom Patriot 12" antenna about 32 ft off the ground on a metal pole and I ran a factory made 75' of RG-8 coax. I had about 15' left over that I just coiled up on the ground near the antenna for now in case I need to go higher with the mast pole. The radio itself has a built in digital SWR meter but I wanted to check it with a traditional meter. I have an old Radio Shack Micronta 21-525B which has functioned flawlessly for many years for all of my mobile CB radios. It has an 18 inch jumper made from RG59 which is 75 ohm which hooks to the radio then the Micronta SWR hooks to my new RG8 going to the antenna. When I key the mike and try to set the CAL function the meter jumps everywhere and won't seem to calibrate. Do you think that the RG59 on the radio side of the meter and RG8 on the antenna side would cause the SWR meter to go haywire? Can the two types of coax be mixed? A penny for your thoughts. Thanks for a great site.

[@vaccarioou22]

Very useful - thanks Dave

[@stephenwilliams5201]

Antenna launcher. Sling shot/zebco reel. With a one ounce sinker. Up up and away. Then pull to tighten. Adj ist a good day thanks.

[@richardkitchen4430]

Dave. I was told by someone on a forum that if I have a coil with a tap for 40 meters and a tap for 20 meters and have them both connected at the same time that it would still work.

[@neogeo8267]

Great Video - Good production quality, well spoken and excellent info. 73 from North Idaho

[@leovidallon]

Sir what is best swr result for 2 meter antenna which is 25 meters long coax cable @ 144.00mhz..using cp22e diamond antenna..thanks for the responce..73

[@aviatortrucker6198]

Great video Dave! Would like to see same video for a monopole antenna in the 27 MHz band.

[@burnts1enna]

Dave, when you measure the length of the antenna, do you measure the actual length of the wire or do you measure it after you’ve wrapped the wire around the end insulators? After wrapping the wire around the end insulators do you then measure the distance between the insulators, which will be shorter than the original wire measurement, or do you stick with the original length of the wire antenna? In other words to shorten the antenna do you have to actually cut the ends off?

[@MrMikeljay]

Thank you for the information. As a new "ham", I enjoy learning new things. Keep up the good work! 73! KM4QFN Mike

[@TheMaxtracirossi]

What is your comment on building a 80/40M inverted v who's legs are 90 degrees to each other and fed with the same feed line?

[@davecasler]

It’s a tried and proven approach. It’s electrically a fan dipole and works fine.

[@antonybradbury6613]

Dear Dave. I make the dipole length, using your VF of 0.8 to be 3ft 9"3/8' or 45.3/8 per leg.... viz. 299792458 / 52 x 0.8 / 4 (convert metres to inches) = 45 3/8 inches per leg You can use 300Kmps or 468. However, to be exact, and it's no big deal to use 299792458 rather than the above 300 or 468, but you do get the exact length for your dipole,and, when cutting your coax length (using the coax VF) you get the exact phase match to the radio. No matching devices, no trimming of antenna or coax, just an efficient feeder and antenna system. I was not being rude, big headed, more trying to explain a more efficient way to cut your antenna and feeder. I have been teaching my students (new to ham radio) what I was taught using the metric system. However, I was brought up with the imperial (feet & inches) system, but when in 1966 I was forced to change (was an apprentice electrician) to use the metric system. I was no licensed until 1982, but had been an SWL and builder since about 1960.

[@davecasler]

Antony Bradbury Hi Antony. I fear Imperial units are here to stay in the US. I agree the metric system is far better and easier to understand. It's been my experience that the dipole's height above ground and especially its proximity to other metal objects will affect the resonant frequency somewhat. On a band as broad as 6 meters, the dipole can range from approximately 9.36 feet at 50 MHz to 8.67 feet at 54 MHz, with the same variations in feedline length if you want a feedline that is a multiple of lambda/2--it will be an integer multiple only on a single frequency. If you're only going to operate on a single frequency, or on a very small segment of the band, then by all means trim the dipole carefully in advance, though in practice further adjustment will very often be required. Wire antennas aren't very broadband anyway. I used a six meter antenna in the video because it's compact enough for demonstration; I must confess I don't actually use 6 meters because I don't have a suitable transceiver. My primary HF antenna is a horizontal full-wavelength 80m loop cut slightly larger than need be, used with a tuner on all bands. The purists scream (and there are purists in my local ham club!) but the antenna sure does work well. You can see it in About Dave 7, which I hope to release today.

[@iainmeteorscan1555]

Hi Antony. I believe you have mixed up David’s MFI-measured 0.8 coax velocity factor and the accepted 0.95 velocity factor that is applied to the length of antenna wire. For determining the half wavelength of an antenna, the imperial (feet and inches) formula is to divide 468 by the frequency in MHz. For metric, the formula is 142.5 divided by frequency. Both these figures (468 and 142.5) have a velocity factor of 0.95 built into those formula figures, 0.95 being the approximate velocity factor of typical wire used for antennas. Using the imperial formula, David’s calculation for a half wavelength is correct: 468 / 52 = 9 ft. each dipole leg being half of that = 4.5 ft. (54 inches). So, your calculation should have read as follows: 299.792458 / 52 x 0.95 / 4 = 1.153 metres (convert metres to inches = 53.89 inches per leg) in line with David’s 54 inches (4.5 ft.). For those who want to know why the numbers 468 (imperial) and 142.5 (metric) are used in the formulae for antenna construction, see my explanation on: kzbin.info/www/bejne/h3_KpmykmZyZo6M 73.

[@natarajvenkatadri921]

Hi.wud u be able to help me tune a stub tuned HF vertical homebrew antenna? It is a 1/4 wave on 20m & has 1/4 wave decoupling stubs at 1/4 on 15 & 10m.need help tuning.using an mfj 269. Thanks,nat vu2nta

[@junkman2758]

I have been there very cool. Also Have found the geocache there.

[@KEVINPAGEkf4znl]

Looking fo info on the coupling unit for my Delta Electronics HFAS-1 antenna system

[@WauliPaulnuts]

Dave just developed a dipole exactly the way I've been doing for decades; more recently I've been using the mfj259.