2m/70cm Ground Plane Antenna

Easy to build ham radio dual band 2 meter and 70 centimeter ground plane antenna.

[@medhawk4885]

Man this design works great. I made mine out of vinyl covered wire coat hangers that are available at Dollar General stores and elsewhere. Thanks again to Dave for a great idea :-)

[@FergusVoice]

Excellent film, thanks. For spacing - 4 years later, I know - is to use some wire that is the width of the gap wound on the dowel at the same time as the 10 Guage. I made my own rubber duckies for 49MHz years ago - using a ball point pen sleeve and thin copper wire, on a thin plastic sleeve. Glued with epoxy, then removed the pen sleeve, fitted the BNC and sleeved with heatshrink. Got rid of the telescopic whips and got half a mile on a VERY low output radio:)

[@HugDeeznueces]

I have to try this with my dual bander HT. Thanks for the video!

[@w.rustylane5650]

Nice antenna build. I'll have to give it a try once I get my Tech. license.

[@RESlusher]

Great video, Dave! I'm going to have to give that a try!

[@billk9636]

Add to project list.

[@warplanner8852]

Actually, Dave, I built a normal 2m version of this (19.1" radiating element and identical radials) and found it to be pretty good up in the 440 MHz band. Give it a try!

[@philswede]

Great video! Thank you! A bit messy mixing metric and inches. In radio I would prefer metrics only. But now, time to build the antenna! 37

[@brentjohnson6654]

Nice video. I don’t know if you are still active since it has been a while since this video. I am following your guidance and have my 10awg cable coiled up. I am going to use a N-type chassis connector instead of a SO239. Wish me luck. I have a new nano VNA to test the antenna when I complete this project. Thanks for your help and 73! Brent KI5HXM (new HAM)

[@RVArchery]

15:49 - "70 METER section" (hi-hi). Great video, Dave. I wonder how well it would work with two 2 meter radials and two 70cm radials, eliminating the radial coils.

[@davidmay2482]

You could use a trick I learned when learning how to wind my own rings for chain maille. Wind the coils around a piece of all thread. it will help you wind a more uniform coil AND you can clamp it on with a small pair of vise grips.

[@williamwazere]

DAVID MAY nice tip man, never occurred to me

[@FergusVoice]

If you use copper without sleeving you can heat with a blowtorch and it gets really soft to bend to shape!

[@joeaho2577]

I had one of these for 2m about 25 years ago made out of brass brazing rods. It worked great. Think I will try this. de KB0FKT

[@kf4dcy501]

that kenwood reminds me of my old alinco dj191.

[@jockoharpo2622]

Have ou ever considered the egg beater omni-directional antenna? You can't beat it and it comes with an optional whip! Those ground plane type antennas have been thought to have whisked people away like a huge blizzard!

[@jj01a]

is that copper wire you have for 110 lines in the house? cool stuff from someone new to the hobby. Are there any books on antenna theory = designs made from stuff around the house.

[@exploreliving7344]

I have one question. I am very new. Just got my Tech license a few months ago and been working a HT till now. Love the idea of making my own antenna so I have been reading. Your design is simplistic and I like that, but I have one question on what makes this a dual band. Do the coils you put in the wire act as a trap to allow this antenna to work both bands? Thanks for the great video!

[@VE3EAL]

Hi Dave, I always enjoy your videos. Please keep them coming. I have a question about this dual band 70cm/2m ground plane antenna. Will it improve reception as much as it does transmission? There is a simplex net here that I have trouble hearing most check-ins on a long whip on an HT and I wonder if I could receive some of the distant stations better with a ground plane. 73 Eric VE3EAL

[@acestudioscouk-Ace-G0ACE]

Hi Dave, thanks for this, well explained and very useful. Is the coil in the centre a choke for 70cms or a loading coil for 2metres? I'm guessing a choke.

[@scottdonovan4841]

Could you just mount the vertical element to a hood as a mobile antenna?

[@Lualt]

tanks now i know how to make it

[@johngaskell5319]

hi Dave, you are the man coming up with idea. have a questing for you. can you make a cb ssb & 2 meter base antenna all in one.

[@buddhistsympathizer1136]

This is a great design - May I ask, would this operate better than a dual dipole? Arguably, a dual dipole would be easier to construct.

[@Scott-K7sce]

hey dave my man. have you ever tried to put this antenna here onto that 6" round coffee can? i'm sure you can make it work i think it be a killer setup and work better then the monoband 2 meters you had... 73's k7sce

[@yxhankun]

which type of antenna is best for 3 G USB modem? I would like to connect an antenna for a raspberry pi with a 3G USB modem. The tiny computer will house in a small container either set aside in sea water ( near shore) or a hill side.

[@VE3EAL]

Hi Dave. Built one of these and put it on a 6 foot mast on my roof. I am amazed at how well it works. I can hit repeaters 150km (90 miles) away. Thanks for the great design.

[@rickvia8435]

Excellent...

[@graplingurty]

You have a good channel Dave KC0ZQB said that...

[@josemiguez2375]

Hi Dave,thank you for sharing.if i want to tune this antenna in the marine band,around 157 mhz i should cut only the upper section a bit and leave the bottom section like this because the lower section its only for the 70 cm band and the upper for 2m band.am i right?.please,where i can learn more theory about this dual band antennas?.thank you and greetings from spain

[@bbowling4979]

Dave - How could you go about modifying this design to broaden the bandwidth? Is it possible with this design?

[@skreb9566]

Very nice project! Just one question, how much is 10 gauge in square milimeters? 73 DE 9A3DSU

[@marcinmichigan2772]

I put mine on PVC pipe and run the coax thru the pipe (portable) works great

[@marcinmichigan2772]

@@mondo_burrito nothing that I noticed - I used schedule 200 (lighter/thinner walled pipe)

[@z1catfish]

Was a long time ago I know, but like to know the math used to calculate the placement of the coils, I'd like to modify it to a 5/8 wave ground plane....

[@nativetexan9776]

The coil on the 4 ground wires is not necessary. 19-1/2" each will suffice for both bands.

[@jorgecervera1200]

Hi, have you try to make a Yagi dual band antenna, with this design, I mean, start with a dual band dipole and then add a reflector?

[@evdyo]

Have you ever worked on a 2m 144Mhz loop antenna?

[@DrDiff952]

More information on the coils please?

[@Jv977]

Do the radials really need to have the choke/ coil in it?

[@sircyfus947]

why do the radials need coils, can't they just come out straight and use the vertical coil to separate the bands?

[@072032786]

Dear Dave, Do you know this antenna gain and freq between ?

[@brunobassi2440]

PMR 446 mhz Vertical monopole 16.13 cm 4 Radials. 18 cm LPD 433 mhz Vertical monopole 16.61 cm 4 Radials. 18.61 cm 144 mhz Vertical monopole 50 cm 4 Radials. 56 cm Diameter 2mm the inclination (degrees) of the 4 radials +/- SWR

[@dnomyaryevi869]

Could you upload the drawing so I can print them out? Thank you

[@circuit-breakermi3865]

Thanks Dave, nice project. So the 'coil' decouples the 2 bands, how do you determine the length and # of coil turns? I can't wait for our +3' of snowpack to melt so I can mess w/my antennas again.

[@sergiocavazos8963]

have the same question, how to calculate the coil?

[@andreasviklund2385]

Gr8 video! I dont know if you have done it in a previous video, but it would be interesting to hear you talk about SWR and the role cable loss plays with SWR (that SWR is not as critical with low loss in the cable). Also i heard that one can be fooled when meassuring SWR at TX end of the cable contra the antenna end. Tnx and 73!

[@theodoresears4679]

Ground plane near earth? Does it work.

[@jockoharpo2622]

Does it pick up planes that are on the ground?

[@WhateverYuotuber]

Thumb up ..!! :)

[@gverran]

Awesome! I need to put a ground plane antenna together before leaving on holiday and this seems to be the easiest. Just one question though, when you keyed in the repeaters, why do they respond with CW? None of our repeaters in South Africa do this. I even had the same issue while on holiday in the UK earlier this year and thought that something was broken or I just wasn't doing something right.

[@SeekAStrak]

Some repeaters identify themselves with a voice ID while others ID themselves with CW. Sometimes keying a repeater causes it to ID itself if it hasn't done so in a while.

[@ffp1974]

Can you use the same coaxial cable that is used for television in your home? In other words I have cable running to a room that is not connected to anything. I would like to hook my antenna up to it and then connect to that coaxial cable in that room. It would save me a lot of time.

[@n3ssaya972]

You better not. The TV cable is 75Ohm and Ham equipment is 50Ohm.

[@heliumnetwork2871]

Hi, i do one for my miner linxdot for 868mhz , right now im in testing.

[@VE3EAL]

Hi Dave,

[@scottdunn1093]

When tuning can you trim off the opposite end instead of soldering and unsoldering to trim

[@ko4gpa]

Scott Dunn trimming the soldered end is for the 70cm band then trim the top end for 2m.

[@Mrjm5411]

Hey Dave, How far away from the repeaters are you and what power level was the TH79(?) set for. Also are the repeaters in the "clear" direction or through the house or ? Thanks

[@DaveTadlock]

The 70 cm repeater in Lecompton, Kansas is about 30 miles away. The 2 meter repeater in Lawrence, Kansas is about 20 miles away. Both in the clear. The HT is set to 5 watts but is probably only doing about 4 watts out using an older battery pack that was charged about six weeks ago.

[@SkylerF]

Where do you get your machine screws, ring connecters, nuts etc? I am new, and need to get some antenna supplies

[@daveb5041]

You could rip the copper wires out of your walls or could be found at the hardware store. If you ask the guy at the store where the antenna or antenna supply department is they will give you a weird look and say we don't have it. Home depot has a lot too but they are very lacking in little nuts and bolts. You can also get copper pipe for ground rods, wire, glue, and epoxies for it there.

[@eknaap8800]

Do the angle of the radials have any significant effect on the SWR? Since a monoband GP have their radials in a 90 degree angle.

[@FergusVoice]

The angle of the radials affects the polar plot, the droop makes it flatter - and yes, that will affect the SWR. 73

[@FergusVoice]

To go further, a 45 degree droop on the radials will theoretically give you 50 Ohms at the feed point. However, the velocity factor of different thicknesses of wire or tube have to be taken into consideration. This antenna is obviously excellent.

[@user-if2fr6qu7d]

Привет !!! расскажите подробнее о размерах антенны английский не знаю ,но по видео догадываюсь всего доброго 73

[@Vadym618]

Hope that you will read this message. Can you tell me please, what exactly the diameter of wire you have in video? Cause I know, that the diameter of wire changing the capacity of antenna. Video is great! Thank you! I'm planning to do this antenna at nearest time and gonna up high it proximately above 9 meters above ground. Maybe I have to Ground the ground of the cable? Sorry for my English. Hope that you will understand all my text. Anyway, once more thank you!!! Best regards!

[@DaveTadlock]

It's 1/8" stainless steel rod. 1/8" is about 3.175 mm.

[@chrisb3989]

Seems a lot of hassle I just built a 2m version and just used it on 70cm because it’s a third harmonic and it works anyway.

[@jspencer47]

Can this also be done for a 10m if so do you have a video for them or a set of plans thank

[@eknaap8800]

@John Spencer: In theory it could. The elements however are as long as 5 mtr. (16,5 Feet). The radials will certainly bend due to their weight.

[@orhansimsek8935]

pls antenna schematics

[@davidcall3528]

howdoyoubuildanantennaforahighfrequencyradio

[@69Markowski]

Will this work at straight radials? No coils at all, just 4x52cm or so.. 73's Max OH5FCO

[@jcdeer]

that's what im sayin I don't want to do the coils

[@DaveTadlock]

Yes. It will work as a mono-band antenna. Make it the short length, the distance from the feed-point to the coil, and it is a 70 cm antenna. Make the element lengths the same as the total overall length, about 19", and it is a 2 meter antenna. The vertical and radial lengths may need to be trimmed just slightly to tune the antenna. All lengths should be equal and the radials bent down at about a 45 degree angle. Thank you for watching and 73!

[@wimpog97]

+Dave Tadlock How do you know the dimensions of the coils as well as how many turns?

[@JDErrabo]

good sir can i used this to baofeng uv5re? thanks

[@26CW128Jake]

Jerry Errabo Yup, it covers most of the same frequencies. You just need the correct connectors.

[@avichi1avichi]

Mr.Tadlock thank first time builder of home made antenna, I think you idea will work great in my attic as we are in a HOA situation and cannot have a antenna outside, I have already created the radials and the main [total 5 ], now as i understand from the video the 4 radials are a 45-degree to the ground plane , and the main is soldered to the SO-239, Question :I could not make out your installation of the antenna and the SO-239 adapter on the "Clamp" on the back of the video, it would help a newbie how to attach the setup on the clamp and attach it to the pole. Question: Can you please also draw the "Grounding" , can I attach the the ground to the ground already available on my attic? Any advice would be appreciated.

[@mikelee8520]

A very good video as always, but my wife has a rotary washing line outside it looks like an upside down umbrella but with no material, I have been wandering if it is possible for that to be done as an antenna. Thing is my bed would be put in the dog house until further notice. Mike.

[@purplemutantas]

Look up the hex beam. It looks like an inverted umbrella. So it might be possible to use a clothes drier as a frame for a hex beam.

[@user-ty2rr8so4k]

пожалуйста укажите все размеры. на видео плохо видно

[@user-ty2rr8so4k]

+Dave Tadlock именно этой антенны нет.( ссылки в описании тоже нет

[@scotland770]

+Чувак Чумаков: Вам необходима, для 70 см или 2 метра?

[@user-ty2rr8so4k]

+KM4RYI 145.500 и 446.018

[@daveb5041]

How do the coils actually work? Does it work like two antennas and the coil acts as a shielded electrical connection linking the two like a piece of coax, sort of? In other words the RF wave sees two different antennas, because the coil is invisible to it because its a rounded loop like an inductor or choke? Also since this is youtube and people like to read criticism the most I could come up with was this: At 4:05 he shows a diagram with three elements when it clearly has five, he points this out but what if you weren't paying attention to the video, or it buffered at that part? He would be LYING to his audience. That's incredibly disrespectful and misleading. What if you were going to build this for a hospital following the instructions, put three leads on instead of five and the SWR was way off causing bad reception to the ambulance which would miss a call and someone would DIE! All because of lies, and lies for what? Greed, or is it some sick game he plays with viewers minds. I can't believe some one would do this in such a position of power and responsibility. It's morally reprehensible what he's doing. We should start a change.org petition to have this content removed from youtube, all servers and the face of this earth. disgusting. That was the only thing I could find wrong with this video, other that, I plan on building a few different versions of this, good DIY!!.

[@Marksracingengines]

Dave B. please do not disrespect Mr. Tadlock just because you do not understand antenna theory. This is a well thought out design and I am thankful for it. I built this antenna per this video and it preforms flawlessly on 70cm and 2m. In fact I believe it works better than any commercial dual band ground plane I have ever owned. I also have another slightly modified version of this antenna at my repeater site built with 3/8 copper tubing tuned for GMRS on the 70cm and my 2m repeater all on one hard line with 4 notch filters about 150ft in the air and 70cm has about 30mi radius at 25 watts, 2m has about 40 miles on 50 watts. so I must say Thank you to Dave Tadlock.