CB Radio Homebrew Gainmaster 5/8 wave Antenna, on a DX Commander Pole - Lockdown activities Part 5

[@oz457]

Following your instructional video I have also made a gainmaster with a stud of 62 cm. It works absolutely great. Prior to installing the antenna at my friend, I did a fair comparison between the mobile wilson 1000 and the homebrew gain master. The signal difference is +2 S points on the gain master vs the mobile wilson 1000. Both antenna's are at the same level starting from the base. Maybe the gain master was half a meter higher, but just to make sure the RF choke was higher than the metal rooftop of the small van on which I have the portable wilson 1000 antenna. I was doing this comparison in a field with my mobile radio. I have built this antenna for a friend who has severe restrictions regarding antenna's he can set up at his home QTH. He uses 2 fishing poles for a multi band dipole, but he wanted to also have a vertical areal for 11m. When I opened the back of the truck when I arrived at his apartement and took out the wire antenna, he looked at me like I was telling him a joke. He thought I forgot the actual antenna back home as he saw me grabbing only just some cables. LOL. He was expecting a fancy, sexy antenna! After we went up in his apartment on the highest floor, we took down one of the fishing poles and mounted the gain master. I just used one of the fishing poles he currently uses for his dipole antenna. So he can use the gain master in a vertical polarization and his dipole for the other bands. After installing, I made one single call on t5 and boom, a station from Poland came right back. His face was still like very skeptical, but after firing up the lincoln radio and have a polish station coming back after one single call, he fell off his chair. So, let me confirm that this antenna really works well and is comparable to a Antron 99 or any other antenna out there that has no radials. Thanks for the video and I hope to hear you on the air some day.

[@RC-Heli835]

What kind of fishing pole is 25 ft long?

[@cedarridge3020]

@@RC-Heli835 Deep deep sea

[@Jimmyboy1674]

@@RC-Heli835 a beachcaster!🤷🏼‍♂️🤣

[@stanner9474]

He'd actually get better performance from an A99 or Imax due to the fact the GainMaster design is a balanced antenna which is extremely sensitive to being near anything which can play games with it's pattern & TOA. I've tested & compared my GM in multiple installations from camping to mobile to home both high and low and only when it's way high in the sky and not near anything else does it come alive and kill everything else it's compared against, including a Vector4K and an I-10K. However, mounted down low or near any other antennas, trees, towers, etc. it totally *_SUCKS_* compared to almost anything else. Just the nature of the design, it's two radically different performing antennas depending upon the installation.

[@JAFO.]

@@stanner9474 Agreed! Same result when I ran several comparisons with my original GM, up high it reigned supreme, down low and/or near other antennas, bldgs., etc. it was a steaming pile of canine excrement.

[@ChristianmorrisMlpro]

Thanks for this video, I just finished making mine. It has a 1.1:1 SWR right across the mid block, and the receive is excellent. I’m very happy with it overall.

[@RC-Heli835]

What are you using to string your antenna up with? Mfj makes a 33ft telescoping Fiberglass pole for 99 dollars but I'm not sure how long it would hold up in a permanent sort of mount. These are so tall they pretty much need taking down in a wind storm. I thought I might find a 25ft cane pole.

[@furion..]

I made my GM 5/8 from Belden RG-213 for higher power handling and stuffed it into a 20' Stationmaster 3.5" fiberglass radome but had to drill through the brass tip and extend a Wilson whip up & out through it about 4' to fit the entire affair. Sure stomps the old Vector 4000 and isn't temperamental in the rain & snow!

[@RolyRJ]

Great video Mike....... Cal better have plenty of supplies :) I will probably make one for 10mtrs and hang it on an Expedition model, it would be great for my DXpeditions to the Pacific (can't wait for decent propagation to return) Cheers - ZL1BQD

[@mike-M0MSN]

RolyRJ Cheers Roly, bloody brilliant antenna, going to rebuild using better coax, matching stub and connectors. :)

[@BoB4jjjjs]

What do you think of this antenna Roly? I have never tried to build this one, but I have had some weird antennas. Some manufactured and supposed to be good and to be honest were crap. One I had didn't work no matter what I did. I was going to have another go at this antenna (I think it was some Italian rubbish) as it never worked, I could almost shout as far! However, i did have its big brother and it didn't half get out. So I was just going to take it to bits to see if there was a transformer inside it that was not quite right. But I can't find it, along with some other antennas that appear to have vanished! They were here at one point, but now have been spirited away! Strange as shed is always locked if no one here. Never mind. Question is, is this antenna a go or is it just another weird one?' Strange design for a CB antenna and I have not heard of anyone using it.

[@dxscotland5901]

Most folk cook in the kitchen but Mike makes antennas 😂 good job👍

[@mike-M0MSN]

😁

[@simov8chevy]

Ha haa, not the first time I've done something in the kitchen to upset the xyl. Best one was a BMC 950D engine block upside down on the gas cooker with a ring on full to heat the block to try to free off a seized piston. Have also left a few too many soldering iron burns on one of the work surfaces but have managed to blame some on her puting hot pans down lol.

[@simov8chevy]

@Adam J McLeod One of the reasons we had to get an electric cooker when we moved house. Also used a piston from an old brake caliper as a solder pot for tinning wires. Put piston upside down on burner and fill with solder. Gas ring on low kept solder at ideal temp for tinning lol. Ohh my poor long suffering wife lol.

[@Bass-guitarist]

For making the coax air choke I get a 2ltr bottle of fizzy drink, open the bottle and drink about a large glass out of it, then put the lid on. Shake the bottle a few times and it goes rigid with the gas. Wind your coils using the bottle as a former and then tie together with cable ties and/or tape. Then to release the coil open lid of the bottle and let some gas out compressing the width of the bottle to slide the coax coil off the bottle. Works a treat! 161 De. M0KTY

[@mike-M0MSN]

cool

[@StuartM0TTQAmateurRadio]

Great video. I've made them in both RG58 and RG8X (allowing for different VF and pF/m in RG8X) and there is a marginal improvement in performance with the better coax. I've used both for 11m portablewith a 10m pole and the bandwidth is a huge asset. Next up is to make one up in RG213 with Westflex for the stub (because the consensus is that if there is a part of the antenna where loss can creep in, that's it).

[@mike-M0MSN]

Great tip! reckon the RF choke will be OTT with 213!!! LOL

[@StuartM0TTQAmateurRadio]

@@mike-M0MSN Yes, you're right, I will just reuse the RG8X choke and stick a socket on the bottom of the 213 section

[@niftyfiftycampingadventure795]

Awesome upload .. I have the Hawkins pre built for 26 and 27Mhz . Used for mobile static.. Very happy with the performance.. Great application for field days , camping etc..

[@mike-M0MSN]

Great 👍

[@hardcorsaratoga0130]

ok great work now i am waiting for the hi-end version of the 5/8 and the 1/2 gainmaster to get the absolutely most out of it keep up the great work

[@Joe-KN4IFI]

Great job Mike. Cal's pole holding up an antenna made with RG-58. Oh the irony ! lol Great video Mike 73 Joe

[@BoB4jjjjs]

Yeah, RG58 on Cal's pole ha ha ha ha he will love it! Oh the loss of power between the set and the antenna!!!

[@lucianocerda6894]

Mike, the antenna was 100%, indeed I cut it by 3 cm, it was excellent 25 Mhz. 1.3 by R.O.E. and in 30 Mhz. 1.4, THANK YOU VERY MUCH !!!!!!

[@mike-M0MSN]

👍

[@anti-corruption-anti-tyranny]

Love the makeshift cable holder whilst soldering (measuring tape) excellent video, however I do not possess the soldering skills you made it look so easy . I will just buy one lol 73s

[@TechMindsOfficial]

Very nice bandwidth on that, might have to try this myself. Great video 👌

[@mike-M0MSN]

Cheers Matt

[@DXCommanderHQ]

Just re-watched this one Mike.. You made me one a couple years ago - I think we should get it up, hooked over a tree in the woods! (I think I know where it is!)

[@greasydot]

Brilliant antenna you cooked up in the RF Kitchen

[@lu4dpl1977]

Hello, I'm LU4DPL, the video is very good, it has a plan with the measures to better understand the assembly, thank you very much

[@huguesmassart4483]

Amazing job ! Did you use only rg58 ? Some tutorial are usine rg58 and rg213 ?

[@RC-Heli835]

I finally have all the stuff on the way to build this including a Nano VNA.😀 Just need some type of pole. Cant wait!

[@mike-M0MSN]

Nice!

[@yaripedone217]

good job and great tutorial! Thank you. Do you think this antenna will be ok for my old AM Cb?

[@mike-M0MSN]

Yes it will

[@lee2e0wyk60]

This one will be popular, there a great antenna. Nicely done 👍

[@M0RMY]

Mike - this is fantastic - my favourite CB antenna too! Well done mate very impressive.

[@mike-M0MSN]

Tom Rowlands Thanks Tom..

[@BoB4jjjjs]

Hi Tom, I take it you have used this antenna before. How does it perform compared to other antennas? Just wondering, I am not going to build something that does not perform well and does not come recommended by others. I am disabled, so building something like this will be a lot of effort, but it has never stopped me in the past. Only problem I have these days is getting someone to give me help put antennas up on a pole etc. I hate moving house, all the help vanishes and when your father dies that is the end of it. Give you a laugh, my grandfather who was 82 at the time was up on top of a three story building taking down an antenna for a Radio Hams wife, I had visited him in hospital and promised him I would take down his antennas if the worst happened. The worst did and I drove over one day with my grandfather expecting him to stay inside so I could pass the antennas through the window to him. I head a voice behind me and there he was climbing up the roof behind me. I tried to get him to go back inside, but he wouldn't and insisted he helped. It did make things a bit easier as he had a Silver Rod and a few others up on the roof. The gave him the Nock name of "Ground Wave Jim" it appeared to be a joke in the Ham Club, but if it was I never was let in on it. Can't even remember his call sign now, it was a G4 anyway. Ah the memories, but that was before things turned on me. My grandfather was fitter and more able then and at 88 than I am now! Some people have all the luck. Anyway, take care as I think you are in the high risk sort of job? I am away to throw some boxes around with the neighbour while he is still at home to give me a hand tidy the workshop/Man Cave/shack. I should have gone through my licence 30 years ago when I was a member of the Ham Club. But job got in the way then girls and motorcycles and then one girl just would not let go! So married life got in the way. Now not being fit, after cancer and repeated work injury is just a bit to much. This on-line testing is my chance to do it now though. They told me I would be in a wheelchair before now, 10 years ago, but still getting around with two sticks. Be lost without the car though! 73s as they say. Be interested to hear what you have to say about this antenna though. How about a DX COMMANDER for CB?

[@M0RMY]

bob fourjs hi Bob Yes I have a Gainmaster commercial version of this antenna. It really is a great antenna and better than my Antron 99. It’s a 5/8 wave antenna and very good. I use my DXC on 11m all the time! It’s very good too. Although the wire is cut for 10m it’s is 2.5 SWR on 11 and easily tuned by radio ATU. You could cut an 11m wire on a DXC specifically if you want.

[@BoB4jjjjs]

@@M0RMY Thanks for the reply Tom. Maybe I will give it a try once this virus thing is gone.

[@joerowland7350]

@@BoB4jjjjs I'm in the about the same condition but I just keep on going hOpe you do to! Radio helps 73 n9prf Joe

[@richardwalker4890]

Mike great video. Made a couple of these now and they work great. Do you know if its possible to scale one of these down to work on 4m /70 mhz. As this band is becoming more popular but the choise of antenna seems very limited. Its almost the same antenna just badged by different makers. Think if its posible you ans Callum could be on to something. It wpuld Definitely make a great video. All the best keep up the great videos. 73.

[@mike-M0MSN]

I will try that.. :)

[@M0JBM]

Another fine job in the kitchen you must get a shed ;o)

[@mike-M0MSN]

Got a shed.... full of the wife’s pot plants.......

[@BoB4jjjjs]

@@mike-M0MSN ..............plus kitchen sink, cooker, washing machine and the wife, Mike has the kitchen!

[@markramsay6399]

Great stuff. I was really digging the background music too :D

[@jaysaw8151]

iv got a lot of used coax and cant afford another base antenna im gunna give this a try ...im US i sure wish you could have told us by inches but its ok lol thanks for showing us all

[@thomasross3055]

Brilliant. . Thanks... mind you fingers with that Stanley knife.. and love your kitchen worktops btw.

[@Dazzwidd]

I'll also inform you, that the westflex coax that is largely air cored, has a higher velocity factor than normal solid polyethylene dielectric coax so you making the stub longer in the absence of Westflex 103 was the opposite to what you ought to have done, it actually needed to be shorter. My experimental fm antenna I mentioned used RG213 as the stub and I not only recalculated the stub length based on wavelength difference but also recalculated for the difference in cable velocity factor. Just thought that I'd give you an explanation of why the SWR was high on this one. Anyway, cheers and good video 👍

[@mike-M0MSN]

Yes well spotted, it seemed to work better with a longer length?? however, Mk2 not recorded used a shorter length of Mini 8 and worked as well. :) it's fun to experiment..

[@Dazzwidd]

@@mike-M0MSN Do you have mk1 anymore?

[@Dazzwidd]

@@mike-M0MSN I'm not sure what you were saying in the reply to be honest. Are you saying it worked better with a longer length of the coax you used for the stub? It is impossible to tell what you meant

[@mike-M0MSN]

Yes, I do not know why, all of the remakes I have made needed a slightly shorter lengths but that one required just over a meter? I do not have it now so I cannot check to see if I shortened the stub or left it open!

[@Dazzwidd]

@@mike-M0MSN okay mate.I think it would likely be that it was so much longer than it needed to be that it seemed better going even longer 😂 The 3:1 SWR I saw on the video was pretty high still. Its been a while so I was just playing around with some numbers. Velocity factors. W103: 0.85 RG58/213 P.E Dielectric: 0.66. 0.85 over 0.66 = 1.28. W103 stub length 72cm. 72÷1.28= 56.25cm. A stub out of RG58 or RG213 needs to be 56.25cm long or just under 16cm shorter than it's W103 counterpart. So you're might have been nearly twice as long as it needed to be 😅

[@cedarridge3020]

Having messed about with the Sirio GM for a couple years I found it came alive when: 1.) Installed at 12.5m (41') to the bottom 2.) Kept far far away from any & all other antennas, trees and obstructions.

[@mike-M0MSN]

yep..

[@stanner9474]

@Maverick Chester I don't know about him but over basically sea level ground at both ends, I've had contacts up to 130mi when the D layer isn't any good and those contacts weren't even weak! It's like being on a mountain when it's alone & high in the sky. I ended up making one using a 20' long Stationmaster ray-dome (with a rod protruding out the top a few feet for the proper antenna length) for supporting mine made with RG-213 and able to handle 3KW pep.

[@Dazzwidd]

Some years ago, I scaled this antenna to the fm broadcasting band to do comparitive tests with very low power compared to a 1/4 wave ground plane. I got a great SWR and it was significantly better than the ground plane

[@wildbill1]

Great video . Now I would like to make one like that for the 20m band. Not sure of the measurements for a 5/8, and no ground radials?

[@Jimmyboy1674]

1.5 to 2.0db gain! Awesome antenna!👍🏼

[@mike-M0MSN]

Sure is!

[@lucianocerda6894]

Hello, I have learned a lot, regarding this antenna, I liked it a lot, because of its simplicity, and operation, I have seen that, for the Sirio gm antenna, it indicates within its instructions that a metal mast must necessarily be installed, this for not having ground planes, does this also apply to this antenna? Thank you

[@mike-M0MSN]

No I use this antenna on a Glass fibre pole. no metal ground plains..

[@lucianocerda6894]

@@mike-M0MSN Ok thank you very much, very grateful.

[@lucianocerda6894]

Excellent video, very easy to make this antenna, I ask can all the cable go inside the pvc mast, or should it be outside? Thanks and Greetings from Viña del Mar-Chile

[@mike-M0MSN]

inside is ok but the coil outside

[@lucianocerda6894]

@@mike-M0MSN thank you very much, greetings

[@greasydot]

Mike what size pole did you attach it to. Cal has quite a few sizes to choose from.

[@vk2yi81]

Great vid. Just wondering if the choke can be compensated with some ferrites instead. Or is that part of the length of the antenna? 73's.

[@mike-M0MSN]

It could work, give it a go. :)

[@Dazzwidd]

It could work but if the ferrites get hot then that's incurring losses, transforming your signal into heat instead of radiating it. If you do try ferrites, go type 43 sleeves and probably 8 of them or more as you're after a several thousand ohm choking impedance. The air cored choke is cheaper and not as likely to be lossy, but no harm is gained from experimenting. You might gain a little more bandwidth from using ferrites, but like I said, you want several

[@Trinitystillmyname]

I put a "cb" element on my dx commander. Why not just use the driven plate and add to or replace other bands on the classic commander? I like cb bands, just not sure in my mind if this is the best way to go about it with the commander kit

[@CB-RADIO-UK]

Great video. Really interesting. Thanks for sharing.

[@mike-M0MSN]

Cheers Fred. :)

[@franciscolopez3229]

This will be a great project. Can I use RG58 for the whole antenna?

[@mike-M0MSN]

Yes, you can

[@spirittravels.]

nive video. what camera ru using? quality very good.//plus music at 7.20 please?

[@mike-M0MSN]

iPhone 11

[@yonellrumte]

Thanks for your great instruction to build the homebrew gain master. I have one question: When i use H155 Low Loss instead of RG58 and Aircell 7 for the stub - are the length the same or have i recalculate the length because of the different velocity factor? For example -> 153,33cm instead of 126,5cm. And did you tried it to build a 0.64 instead of a 5/8?

[@mike-M0MSN]

I took the measurements from radioaficion.com/cms/sirio-gain-master-homebrew/

[@floris-janvanfleppensteyn4100]

@@mike-M0MSN it's gone the link, Mike can you or someone else re-upload the project?

[@giovanniilari7494]

Hi, thank's a lot for video, vy fine, a question:can i make stub with rg58 coax, why have you used westflex 103?thank's

[@eknaap8800]

All in Metric. Good for you! 👌

[@xszl]

Good for most people, since most countries use the metric system.

[@eknaap8800]

@@xszl Trust me. It's good for ALL people if we were to use metric.

[@26tm9999]

That was brilliant well done and thanks for sharing.

[@mike-M0MSN]

Many thanks!

[@toby000000]

Really good informative video - thanks for sharing

[@mike-M0MSN]

Glad it was helpful!

[@lucianocerda6894]

Indeed it is made with rg58, and I gave it a measure of 72 cms., Should I shorten it then? Thank you very much for your advice.

[@lucianocerda6894]

Ok Mike, I cut 1 cms. and where it turned out well, it was 51 cms. r.o.e. in 25 MHz 1: 1, in 30 MHz 1.9: 1, Now I just have to put it inside some tubes and install it (PVC tubes, reinforced with fiberglass, made by me).I couldn't send photos.

[@mike-M0MSN]

Maybe cut the driven element (Top section) by 5cm to see if that makes the roe Better on 30 MHz.. :)

[@lucianocerda6894]

@@mike-M0MSN OK, I will do that and I will inform you how it looks, Thank you very much for sharing your knowledge, very grateful.

[@eliezercohen2205]

Where can I find build instructions? Thanks for the great video!

[@mike-M0MSN]

not sure an internet search should find something

[@hardcorsaratoga0130]

would it help to use Massi & Paloni 7 mm coax instad of the usual RG58 and allso for the 1.5 mm copper cable can this be upgrated to get a better result greetings Cor

[@2e0wsj]

Well done from 2e0wsj in Northampton

[@lucianocerda6894]

Hi Mike, I built it according to the measurements and connections of the video, but I want to ask you a question, at 25 MHz the roe is 1.0, but at 30 mhz, it indicates a roe of 3.4, I reviewed all the measurements and they are well, how can i adjust it? thanks in advance. greetings from Viña del Mar-Chile

[@mike-M0MSN]

Luciano Cerda what coax have you used and it sounds like the driven element is to long... maybe cut the matching stub (if made from RG58 to 50cm).

[@gabrielM1111]

I can't understand how the radiating element work because it's really not connected to anything when you cut the braid at the capacitor can you please explain

[@mike-M0MSN]

RF is an AC current/voltage so it passes through the capacitor....

[@greasydot]

It works just like a gamma match

[@martindavies6640]

Mike loved all your videos and' have made one of these home made gain masters antennas' and it works a treat'. was wondering if you made one' with different coax/ like rg8x and maybe a rg213 coaxial stub? . if you did what would the dimensions for the antenna be from the coaxial capacitor to the coaxial stub. thanks again keep up the good work cheers Martin.

[@mike-M0MSN]

You will have to try it, I think 213 maybe a little too big for a stub!.. anyway good luck :)

[@K5KAB]

I tried this antenna using Rg 214 and the stub was made with Rg 213 . CB band perfect but at 28.500 mhz I had a 2.4:1 and a 3:1 up to 29.300 it got better at 29.600 at 1.3:1 . How can I tune the antenna for a better SWR on 10 meter? (((((((HELP)))))))

[@josephmusialowski5498]

Hi Mike. Just a quick thank you for your video on the 5/8 cb antenna. I have made lots or wire and ali tube antenna and some have worked right away and some have not and taken for ever to get right. But I have to say following your video and refering to the comparison still shot at the begining of your video the 5/8 was was made very quickly and was on a 9 meter pole and working europe in no time . To get copies back from easter europe on 12 watts usb is something else . Only my Moxon has done better. Thank again. Joe. 73.

[@mike-M0MSN]

joseph musialowski That is great news Joe, it’s a great antenna. Thank you.

[@Calderone81]

Hi! great stuff, about the westflex cable, so i can use RG58 for the matching stubb but make it 100cm long instead of 72cm?

[@mike-M0MSN]

Hi, it depends on the make of coax and the capacitance, I got away with 1m on my construction, however others have reported having to use 3m (for the cost of a metre of Westflex around £1.75 (UK)) your better off using the right stuff.

[@ronnyv.d.b.8152]

verry nice,i working white the orginal gainmaster 5/8 but i like this movie so maybe i kan do it also at meself,,✌✌✌

[@mike-M0MSN]

yes give it a go.

[@RC-Heli835]

what was the matching stub made with on this cheaper version? Also you said it wound up being 100cm. How do you determine that length by trial and error and continually checking SWR? This reminds me more of a JPole antenna with it being shorted to ground. Only difference is the added capacitor. A JPole can have its polarity reversed to where the center pin goes to the short side of the J and ground to the long side as this is. A Jpole has an air choke as this does. The bottom of the Jpole is identical to a matching stub. I'm not sure exactly what the capacitor in this does or how it functions.

[@mike-M0MSN]

You will possibly find that you will need to cut the stub shorter ( I used RG58) as I realised that I had not closed the stub, the Capacitor widens the band..

[@andrearriu539]

Hello there. Did we just had a Qso on 27.305? Anyway, nice video and a good job. Friendly regards, André.

[@mike-M0MSN]

Sorry wasn't on tonight, but keep your ears on.....

[@lewisnewman3443]

I’m confused,you have a few videos on how to make it. Which one should I follow?

[@mike-M0MSN]

both are the same, just pick the one you like

[@abduljalilebrahim6017]

Homemade on another level

[@mike-M0MSN]

Many thanks

[@johnnyjohn6527]

building this thumbs up buddy . 😄

[@avayaguru6679]

Could you do the same but make it .64 or would that not work?

[@kevsmith5363]

why is your vswr so high something wrong sorry looking at the power meter

[@BoB4jjjjs]

I am all for people making their own antennas, it is one of the few areas that most people can play with these days. I just wondered how well it performed. But then if you have no other CB antennas to compare it to that will be difficult to answer. However, it is a shame you didn't spend a little time on the air (maybe this is another video?) testing it, though I do realise it was just a temporary fixture. I still would have liked to see it working or at least some performance figures as in distance achieved and reception performance (though a bit of wire near enough the right length will receive) but I was interested in how well it transmitted. Yes, I know it was cheap coax and it was not cut exactly to the design, but I am still interested how well it did?

[@mike-M0MSN]

I will try to do a video later, I have the real Gainmaster on my roof, and can say the home-brew performed almost as well, problem is I cannot get the home-brew to the same hight so cannot really do a like for like.......

[@BoB4jjjjs]

@@mike-M0MSN No matter, just use it where it is, we can allow for it being on the ground. Thanks for getting back to me.

[@RC-Heli835]

Are you using a standard PL259 below your coil and then using like a male x male barrel connector to connect your feed line?

[@mike-M0MSN]

No it’s an inline SO239, you also need to watch my other GainMaster video kzbin.info/www/bejne/en2nlYKbpcakbc0

[@RC-Heli835]

@@mike-M0MSN Is it the solder and crimp kind? Anytime I've needed an SO 239 I've gotten them out of junk CB's.😀 My ladder line Jpole wire 11 meter has one and my Trucker 2000/dipole. I put one on some coax to get the antenna higher. I'm watching the other vid now. Skip is crazy tonight. I heard someone 2,143 miles away a few moments ago.

[@xanaka530]

Hello 73 ! what do think about gain master 5/8 on fixe vs other antenna , antron , imax , mantova ? She is very good for me , Olivier french Normandy by

[@mike-M0MSN]

I prefer the GainMaster over any of the competition. ( personal pref)

[@mrbeach3379]

Hi mike, just followed your instructions and for uk fm cb radio band got swr of 1:8 on ch1 and 1:9 on ch40. What do i use to lower the swr i have the matching stub at 100cm at present, do i trim/ lengthen the matching stub or trim / lengthen the stranded copper wire at the top? Thanks Mark

[@mike-M0MSN]

Trim the matching stub, start by removing 5 cm and see. 👍👍

[@mrbeach3379]

Mike-M0MSN thanks mike worked a treat have 1:3 on ch1 and 1:5 on ch 40!

[@fnordist]

What is that exactly? a mechanically lengthened half-wave dipole that was electrically shortened with a capacitor?

[@mike-M0MSN]

no idea

[@georgetsilojohn1667]

16 coils is the ideal number or do you know a better option? I think somewhere there is a performance table for the performance of the coils. Does anyone know how to direct me on this? Thank you

[@antenaseinterfacescb]

Tks fer charing this project. I made one 2 years ago with very good results too. I have one question what type of coax you use in this project? I use rg58 66 VP. Very nice project 7351 from 31PAT867.

[@mike-M0MSN]

Cheap Value line VLSR40902R100 not the best, but ok for testing stuff.

[@antenaseinterfacescb]

@@mike-M0MSN tks 7351.

[@Dazzwidd]

you'll be fine with RG58, but if you wanted to adapt the whole antenna to being made from RG213 it would be an awesome antenna if done right. It would handle some watts too. One wonders how this would sing if scaled to 20m. Hmmm it's all possible!

[@peterfischer68]

cool gemacht....herzliche Grüsse vom Lake constance austria...Peter

[@mike-M0MSN]

Peter Fischer Danke

[@peterfischer68]

@@mike-M0MSN will build the antenna. let me know if you are broadcasting on channel 40FM from 8:00 every evening after time europe maybe I hear you Best regards Peter from Lake Constance

[@ironhead320]

Does that work on 10/11 meter wish I could find that online somewhere have to keep stopping video going back to double check

[@mike-M0MSN]

yes

[@PatAutrey]

Is the coax distance from where the stub attaches down to the coil a specific distance? If so what is that distance please

[@greasydot]

218.5 cm

[@furion..]

Cool background muzik, who is the artist of the piece playing at 5:10?

[@mike-M0MSN]

I cannot remember sorry..

[@furion..]

@@mike-M0MSN *_NOOOOOO!!! My life is OVER!!!_* 😉

[@WillieJu]

Whats the distance from the matching stub to the start of the choke/coil?

[@mike-M0MSN]

218.5mm if you pause the video at the very beginning there is a diagram. :)

[@bill53uk]

where did you get the instructions from with all the measurements from.

[@mike-M0MSN]

bill53uk google search

[@peterpauldonoghue7024]

Hi Bill53uk. I'm going to have a go and building this myself .. radioaficion.com/cms/sirio-gain-master-homebrew/

[@macgyver5108]

Is there a 2m version of this? What's this style antenna called and what plans did you use?

[@mike-M0MSN]

No idea what the type/name is called

[@macgyver5108]

@@mike-M0MSN ahh, bummer...

[@john-paulattwood4515]

Regarding the impedance matching stub: As the core is connected to the braid here, how come this doesn't present a short to the back of the radio? I realise that RF is different to DC but would like to understand this properly. Thanks!

[@mike-M0MSN]

Difficult to explain here, but the matching stub acts like a resistor and capacitor in one, if the aerial was a 1/2 wave dipole the centre point would be at around 73ohms (close to 50ohm) and would represent a good impedance match to the radio and no stub would be needed. However, this aerial is a 5/8 wave so the centre point is probably closer to 350ohms so to bring the impedance down closer to 50ohms we need to add a stub. The stub is inductive with a reactance equal to +j300 and neutralises the capacitive reactance in the above 50-j300 ohm impedance thus leaving 50 ohms resistive and a 1:1 SWR on the coax to the transmitter. so the transmitter does not see a short circuit but a 50ohm load....

[@john-paulattwood4515]

@@mike-M0MSN Thank you! 😃

[@mike-M0MSN]

kzbin.info/www/bejne/mInLZ5WDr9Vmh8U

[@john-paulattwood4515]

@@mike-M0MSN Black magic! Welcome to Hogwarts 😅. At least I get the idea now that the stub is resonant in exactly the right way.... Thanks 👍

[@zaperfan]

Great job

[@prizeking1647]

How much power can this take on fm being made form rg58 ?

[@mike-M0MSN]

200 watts ish

[@lapte2019]

Hello, this homebrew gainmaster is better than sirio 827 ?

[@mike-M0MSN]

Maybe? 👍👍

[@timmack2415]

A 5/8 wave antenna NEEDS a ground plane to work against to be efficient. You can usually get away without radials on a 1/2 wave vertical antenna, but not a 5/8!

[@mike-M0MSN]

Tell that to sirio (www.sirioantenne.it/en/)

[@timmack2415]

@@mike-M0MSN It's just basic physics and well established fact. The link doesn't work, sadly but as far as I know, Siro uses ground radials on their 5/8 wave antennas.

[@mike-M0MSN]

@@timmack2415 I don't think you understand the antenna is a dipole, it already has a ground plane (from the capacitor down to the top of the coil)

[@mike-M0MSN]

@@timmack2415 new link. www.sirioantenne.it/en/products/hf/gain-master

[@timmack2415]

@@mike-M0MSN You're right. I'm not familiar with the them. I should have looked at it before I commented. The link doesn't work, I'll have to look for it, is it a 5/8 wave?

[@JayHughart]

I am in the testing phase of a 10KW colossal from Zero Five and no fault of theres (they adv bandwith of 600 khz) I am not happy with the BW. So I took off the "Pipe capacitor) and mounted a Air capacitor ( like the tuning of an old tube type) in its same location and I am going to put a 3 RPM motor on it so I can remote fine tune it (When I wish) But it seams to me the (Gamma?) Match on it is severely limiting my bandwidth So I am thinking of making a 10 AWG coil for it. Guy at zero five says I will loose performance. Anyhow is this a good Idea? Anyone have ANY input? Anyone have a "Starting point for the coil? I can normally figure these things out but info on 5/8 matching networks has not been easy to come across. I do have a NANO VNA and trying learn as well.

[@jamesgeorge1709]

You are in deep kimchee now. Why not build a 11 meter efhw?

[@mike-M0MSN]

EFHW why??

[@johaivid3148]

is this antenna suitable for baofeng uv5re

[@bitemykrank1970]

NO it's a HF antenna. Your radio is UHF

[@jfrphoto01]

@@bitemykrank1970 UV-5R series radios are VHF/UHF not just UHF.

[@seanfox7715]

Hi can you tell me the length from the choke to the three way coax junction pls

[@mike-M0MSN]

218.5cm

[@alvinpope9315]

Hi what height is best for this antenna thanks.

[@mike-M0MSN]

As high as possible.

[@fnordist]

​@@mike-M0MSN NO! max. 16 meters above ground, at least 1/2 WL why, because above this height the antenna loses its flat radiation characteristics due to the formation of steeply radiating lobes.

[@fnordist]

@Maverick Horse Yes the bottom of the coil. Ideal height about 15-16M

[@tkm707martins]

otima antena

[@NigelDixon1952]

I don't know about your wife's scissors, what did she think of you using a Stanley knife on her kitchen worktop!

[@deenunya7735]

In the Kitchen with HolyEnd Aint what it Shoukd be😁 "Hope tge Wife dont Mind me using Her Scissors" 😁 Youve Stolen her Kitchen😜😁 Hiw High wss the Dx Extended? ,Was tge SWR down on all 1..40..n 19? Nice Vid, Saved it

[@mike-M0MSN]

Dee Nunya she’s the boss. The matching stub controls the SWR it is flat across 3 MHz

[@lucamarianini6158]

hi do you also have the project for the 1 / 2onda

[@mike-M0MSN]

yep search mike-m0msn

[@morneniemand8413]

Hi can i add the 5/8 antenna to a aluminum pole?

[@mike-M0MSN]

nope the pole will act like a ground rod... :(

[@JAFO.]

Only if you made a non-metallic support structure for the antenna and the aluminum only attached below the choke coil. Fiberglass rod would be in order to support the antenna if you're not going to pull it up with twine or rope.

[@SoonDumpingAllGmailAccounts]

You can install a metal 5/8 like a Sirio Toronado on a metal mast but the antenna has to be made with insulators for the radiator going up from there. I prefer isolating mine on fiberglass rod and wrapping a choke below the antenna to keep the RF off the outside of the coax shield.

[@JAFO.]

*_@Morne Niemand_* You could also use stiff ABS tubing, but it's dang expensive@!

[@yucelkoycu2609]

Selam bobin ek arası kaç cm . Tek kablo ve diyer ölçüleri yapabilirmisiniz teşekkür ederim saygılar

[@paolodestro5170]

Vorrei costruire questa antenna per altre bande ma sul web non si trovano le formule. Saresti in grado di aiutarmi? Grazie. 72

[@mike-M0MSN]

la bobina è uguale a 1/4 d'onda, la matrice corrispondente è 2/3 sulla coassiale di base e il condensatore rimane 68pf. Saluti

[@paolodestro5170]

@@mike-M0MSN . Many thanks. I'll try it.

[@martincvitkovich724]

I guess I am just a dummy. All I made of this was someone cutting up coax and soldering red wires to something

[@JAFO.]

I think the red part was someone taping something red somewhere for some reason. 🧐

[@uwepolifka4583]

Interesting antenna concept but if you need a very cheap and very good antenna the Triple Leg is the best. SWR is 1,1:1 (if anybody don´t believe it, try it) At first the antenna works as good with two legs. It looks like a Y when turned arround. All three wires can be flexible litzwire with 4 mm². Length = Wavelength/4 times a shorten faktor 0,96. Angle of the legs are 45° up or 135° down. So it has exact 50 Ohms without any coils or matching. If the angle rises to 90° the resistance becomes 45 ohms if it go to 0° it becomes 60 ohm. Then it is a dipole. You can hook up the antenna somewhere (tree) and splay the legs with a long stick. Center of the coax to the beamer and the shield to the legs, that´s all. sites.prenninger.com/elektronik/_/rsrc/1512980846858/dvb-t-antennen/groundplane/2016-04-07%2012_39_49-Groundplane%20-%20Elektronik-.jpg

[@mike-M0MSN]

I will have to give it a go :)

[@uwepolifka4583]

I found a picture, here is it. www.sofafunker.de/Die%20superprimitive,%20superbillige,%20supergute%20Draht%20GP%20!-Dateien/torstengp.jpg

[@GasFinger1]

Better if iimperial measurements were used

[@GasFinger1]

@John Cliff one of the poisoned after effects with our being in the eu, thank god we had the sense to keep our own money ( even though thats metric too i suppose )

[@tangoalpha8381]

👍👍👍🇧🇷🇧🇷🇧🇷

[@JoseRodriguez-ud2dj]

hello could you put a diagram with measurements?

[@mike-M0MSN]

At the begining of the video 😀

[@peterpauldonoghue7024]

@@jfrphoto01 ... Thanks 🙏

[@brunobassi2440]

venom 5/8 is the economic version of the gainmaster ... less maximum power ... less heavy .... very cheap ... problem that must be painted with a paint without metal particles because it deteriorates quickly. 65 euro! zero fatigue

[@spuddyspud8178]

What's the point if your not going to explain everything

[@mike-M0MSN]

What do you need explaining?