HAM RADIO DUAL BAND 20m/40m Vertical Antenna You Can Build.

Here is a simple antenna you can make from wire that covers the two bands 20m and 40m. Peter G3OJV gives full details.

[@harryszwergstatt2879]

I searched for an 20/40 m antenna for travelling. But now I found it😊 mni tnx dr Peter! 👍

[@Maartenkarperfreak]

Thanks a lot for this 20 and 40 meter design antenna , Peter . thats what i needed here . keep on the good work...73 Maarten...PA3DTQ

[@watersstanton]

Many thanks!

[@WR3ND]

This is one of the best videos I've come across for the scientifically minded new hams. Very well done indeed, and thank you. 73

[@G7GTI]

Hi Peter. I have only been licenced 6 months (M7) this is the first HF antenna that I have built, and used this video as a guide. It is mounted horizontal in my loft due to space restrictions but i made my first overseas contact on it and worked a station in Barcelona on my first attempt. Very happy, many thanks 👍

[@watersstanton]

Glad it helped 73 Peter

[@ScientistPrepper]

Always enjoy this channels videos. He saves you months of reading.

[@watersstanton]

Glad you like them!

[@onewolf3750]

Another little gem ,Peter, done with quiet, laid-back, logical delivery. As a new ham your videos are very helpful. You never assume greater knowledge on my part than I actually possess and your calm presentation helps me to realize that I can do things like this. It's always a pleasure to see what you have up your sleeve next. Tim Desmond K3LSU

[@adzbasslines268]

Good job Peter! I've built all of the small multiband antennas you've presented on KZbin and they work well! I especially like the 40m mid loaded coil EFHW with the base loaded 80m resonator!

[@G5STU]

Enjoyed watching, never stop learning, or relearning what's we've forgotten :)

[@davidedwards5461]

I feel the same way lol...GM4GLG

[@basshorseman998]

Peter, I've been saving this project (with your design) for two years only to find that now, this year I shall need to build it after all...Thank you again good Sir

[@111111111Tiger]

I'm all coiled up and choking.. lol I'm in the USA and enjoy your vids. TY

[@darz3]

As a beginner I am really enjoying your channel

[@watersstanton]

Welcome aboard!

[@digitalshack8793]

Peter, thank you for this, well described without being too exact, as everyone's environment is different. It forced me to learn some principles.......It has been a productive weekend and now able to work 20m & 40m. Have enjoyed many of your other videos as well.

[@watersstanton]

Many thanks. 73 Peter

[@justiceforall8574]

Peter another great video,Thanks

[@watersstanton]

Glad you enjoyed it

[@yv6eda]

Very interesting video... as usual, thanks!

[@bvds2007]

Excellent video!

[@watersstanton]

Thank you very much!

[@norbertstepien9185]

Excellent video! thank you.

[@watersstanton]

Glad it was helpful! 73 Peter.

[@opk157]

Thanks Peter, I wholeheartedly agree, experimentingwith antenna's is great fun. Is a bit of a dark art, as it often results in an unexpected outcome, but fun nonetheless ;)

[@horsetrainingresources]

Excellent as usual! Thanks. Could you suggest an additional coil + length of wire to add 80M to this? Would that be feasible? I'm thinking of throwing a line up in a tree and hanging instead of using a pole while out hiking/camping. Having 20+40+80 would be ideal.

[@davidedwards5461]

Hi Peter, Thanks for another great video. You often mention type 43 material but I wondered what the real difference is between that and the type 61 and 31 materials? I know mu and all that "other magnetic stuff" is a bit different but does it really matter say in the 160-6m bands?

[@robinbrown7019]

You are the best

[@watersstanton]

Many thanks. 73 Peter

[@Mottersmotters]

Some advice needed. Great video. I've watched a handful of times now. Just built one in my garden. I have 8 - 5m radials to start with. I have done the first section 20m band got the swr to 1:1.09. I have a former about 40mm and wrapped around 30 turns I am using I think 0.75mm cable. As soon as I solder the coil onto the 20m section right at the top no extra cable the swr jumps to 4 on the swr. I need to ad a small bit to bring the 40m down as its res about 7.6 What am I missing with the 20m as the swr was perfect 👌🏼 Just done some googling and I think I need double the coil length to get it to 32ish mHenry as it is about 15 at the moment. Am in thr right ball park? Does the coil have to be magnet wire or can I use the same wire I am using for the element? Motters M7TRS 🇬🇧 73 👍🏻

[@AlvinMcManus]

Lovely video. I have noticed that you put an 'r' in picofarads for picrofarads. Same thing right?

[@rodralph824]

Thanks for this. I have limited space and would like to give this a try. I haven’t been active in 45 years but recently bought a transceiver and want to set it up at my cottage ( Golden Lake, Ontario). I was wondering if you could give detailed info ? Rod VE3 NRX

[@markwheeler8625]

At 8 minutes 36 seconds of your video you discuss your line isolator; what is the black box between your antenna and line isolator? Is it a safe guess to say it is a 1:1 Unun? Thanks for a great instructional video. 73, Mark WU6R

[@migalito1955]

I too enjoy antenna experimentation. Doing so is in my set of top 3 activites relative to amateur radio. The following antenna is a nice winter project that I recently trialed and found to be quite nice to have. Having made half a dozen mag loop antennas for receive only I decided to shoot for one that was efficient enough for transmitting. To this end I settled on 20 meters as my target band and built the main loop as a four foot square out of 4 inch diameter clothes dryer vent tubing. For the part the signal source connects to I decided to try what I was familiar with where that's a smaller inner loop called a sense loop if a receive antenna. I had read the bigger the circumference of the inner loop the lower the impedance. Hence, thru trial I was able to find that a square made of 3/4 inch copper water pipe with 23 inch sides allowed me to get a very good SWR at under 1.5 over a very narrow interval of selected band & called that good enough. My variable capacitor is selectable so I can use one on 20 meters where calculations suggest a 79% efficiency or another on 40 meters where calculations suggest 27% efficiency. I have not tested the efficiency claims, but it does a bang up job on receive from 40 meters up to 20 meters. It can't be used at a higher frequency due to the existence of upperbounds for this style of antenna. It might receive or tune in down to 80 meters, but my capacitor is not large enough for this plus it really was only meant to transmit on 20 meters. This spring I will test efficiency outdoors and if anywhere near 79% on 20 meters I may go to the trouble of installing remote tuning so that it can be placed outdoors. None the less it really does a great job at receiving & I hope experimentation shows that it does a very decent job at transmitting.

[@watersstanton]

Thanks for sharing interesting information. 73 Peter

[@toddbaker8159]

i found the 20-40m info about the 25 turn coil you had on here a better choice for me getting tuned , i think its because i used insulated wire this 30 turn coil video didn't work with coil; & insulated wire

[@bernardpapet632]

Hello, I love your videos and I have a Question about this antenna. In another video I see 2meters for 40 and 5 meters for 20, which is the best ? thank you :)

[@davidhess6593]

Check it out on 17 meters. I bet that it will perform well on that band too. 73

[@WilliamParmley]

I'm definitely going to try this!

[@watersstanton]

Please do!

[@phils2180]

I used an online inductance calculator to build a coil but found the value given to be quite a bit too high. It stipulated 9.2 turns to give 10.9 microH for the materials and antenna height I was using but ended up with 6.2 turns. Experimenting is all part of the fun though, right?😀👍

[@daviddowns715]

Looks like I can build this antenna, What's the overall length of the loading coil, so I can build it

[@gordonbingham4093]

Great video, am going to have a crack at this. How do you connect the coil in-line to antenna wire and how do you fix wire to top of spiderbeam please?

[@watersstanton]

I put eyelet apscrew into top open tube and coil is sure tly soldered to the wire. 7£ Peter

[@ghostedyoutuber263]

Usually when I choke something with a piece of wire, I usually call the wire a garrote ... not an inductor.

[@chanelkuini5883]

Good tenk73

[@watersstanton]

Thanks to you for watching.

[@TR6Telos]

The problem with making a antenna from bits of plumbing is going to them places where you cant find anything. It's a lot easier ordering from waters and Stanton. Wires are not the only thing to transmit, how about using gas as in a flouresent tube, don't ask me how but it's my idea you heard first here. How about a antenna with gain as a beam type but in all directions of the compass. Ie example, 4 beam antennas pointing NSEW and fed with a relay that operates at several million hz to each antenna, higher than the transmitted frequency, so transmitted frequency, ie voice ,is relayed through all 4 directional antennas or more at the same time multiplying the signal with no extra power needed. I have no idea how to do this practically it's an idea!

[@Hasmanean]

The spider pole is 12m tall, I’m wondering whether you could make a 5/8 lambda radiator on 20m (which would be 12.5m) as well as a 1/4 wave on 40m (~9.9m)?

[@watersstanton]

Well worth a try. If I gettime I will take a look. 73 Peter.

[@jamescollier3]

just got my technician's license. cheers. what's a good first radio for 40 & 20m. I would like to start there, please? thank you

[@Pauln0ah]

What kind of bandwidth did you see without a tophat? I love the simplicity of this antenna. Also is there a way to measure the cut of points on the upper and lower frequency of the inductor using an antenna analyzer? I assume it would simply show a did at each end of the cool? Best 73 OM. Paul N0AH

[@terryburge6763]

Hi! I once had an old Mosely V5 vertical and found I could use just the 40/80 trap to make a very good DX vertical on both those bands. I see these combination dipoles with coils giving resonance on multiple bands (40/80/160). I wonder about how efficient a combination 80/160 antenna like that could be. The multiple band wire antennas I see have such a short section giving some resonance on 160 that I feel they can't be very efficient for the low band. Seems like the coils could be reduced in size some thus increasing the length and improving the performance and bandwidth on 160? I'm not so much worried about the overall length as just to get good performance on all the bands. Hope this makes sense. Terry, KI7M

[@watersstanton]

Multi-band often has more to do with bandwidth rather than efficiency. You probably won't drop more than a couple of dB on the kind of systems you mention.

[@F5VMJ]

Hello Peter... What's the 3 turn coil that you drag up/down for? ...I didn't quite get that part.

[@watersstanton]

To adust physical lenght so antenna base is not dragging in gtound. Remember the telescopic mast goes up in steps of around. 1.1m.

[@ssubaihi]

more secrets has been revealed

[@justmejonboy]

Would it be possible to make a centre fed dipole that works on both 20m and 40m band. Being a 1/2 wave on 20m and a 1/4 wave for 40m ? Total antenna length approx 20m (2 * 10m lengths) ?

[@watersstanton]

You describe an antenna that is 20m long. That is actually a half wave on 40m and a full wave on 20m. A centre fed half wave will not work on the 2nd harmonic. So 40m dipole will not work on 20m. But it can be down with traps. Maybe will cover in a future video. 73 Peter.

[@justmejonboy]

@@watersstanton thanks for your reply Peter. I understand that now. From watching some of your other videos would it be possible to put a choke / load on both ends of a 20m dipole to make it a dual band 20/40m ? Thanks again. John

[@geofham8332]

Hi Peter thanks. You say copper wire, is there any difference using stainless wire? The reason I ask is because local squirrels chew through my copper wire but they cannot manage the stainless. Conditions vary so much it is hard to compare, is there a scientific reason not to use stanless?

[@watersstanton]

Not quite as good as copper nut doubt you will notice. 73 Peter.

[@geofham8332]

@@watersstanton Thanks.

[@M7XCB]

Geof HAM@ the old telecom cable the gray twin cord is ideal it copper and stainless and it anti-stretch cable which are ideal I was lucky my friend work's at BT gave me 100M cable. Just make sure to strip the plastic off the wire as the plastic has RF shield.

[@vk3zen-rfdesign980]

picofarads not picrofarads ..no r in pico...however still a great video...despite me being a spelling nazi

[@GrayPlayer]

Sorry, too much extraneous info!