CB Radio: Build a GainMaster (the rebuild) on a DX Commander Pole..Detailed upload
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- Опубліковано 26 вер 2024
- I built a home-brew GainMaster a little time ago using cheap co-ax and it worked a treat, so this time I'm going to build another one using the best quality co-ax for the job.. and wow the difference is unbelievable . 20 mins detailed construction video
Mil spec RG58 for the main antenna body.
Westflex 103 for the Matching Stubb.
More uploads to come...click that bell
Please subscribe. :)
Cheers
Mike M0MSN - Наука та технологія
This is the first 5/8 I've built to start playing around on 11m. Used RG58 and LMR400 for the stub. Followed your clear instructions and ended up with and antenna with SWR 1.2 or lower for 26 - 28.3 MHz and below 1.4 for the rest up to 30MHz. Also got my first CB dx with Brazil from South Africa with a 5/7 5/8 report! Brilliant, inexpensive antenna. Can't wait to tinker around with your other ideas!
How long is the matching stub of lmr 400?
How long is the stub of LMR400?
LMR-400-UltraFlex or simple LMR400?
Hi Mike I made me the gain master and must say great antenna. from 26Mhz to 28.8 swr 1/3:1. I made some qso's on 27285 FM with UK stations and on 10m band with EI7HBB with a 5/9+. I used RG58 and RG213 for the stub. Because I don't have a westflex coax.
I didn't know the length for the stub of the RG213 I started with 1m and the end result is 73cm. for the people using RG213 . 73cm length.
Mvg Nic on5ma
Thanks for this! also i do not get westflex in my country but rg213 is avalaible.. Off i go to building now! :-)
@@Calderone81 good luck with building the gainmaster. Great antenna Patrick . 73 s Nic
I got 60 Ohm. Should I make it shorter or longer?
Mike, I used your plan to make an antenna. I tried supporting it with pvc pipe, but that acted like a wet noodle so I just hung it from a tree using a pulley system. SWR ranged from 1.05 :1 for 28.460 MHz to 1: 1.16 to 1.22 over the cb range 26.960-27.410 MHz it came in at 51.2 ohmsuntil you got to the lower end of the CB band 26.960 came in at 43 ohms. I'm hearing skip from as far away as Corpus Christy, Texas (I'm in North Carolina) over 1300 miles! I actually conversed with someone about 6 miles away and it was a very clear and strong signal. I used DX 400 max from DX Engeneering for the matching stub. Now I have to get mt 10 meter radio configured correctly. Thanks for the videos!
MIKE ITS A BULLSHIT ANTENNE MAKER
Quite a nice antenna. Looks like a pretty good antenna for 10-11 meters. Construction was very well explained. Great video!
Many thanks!
NOTICE THAT THE LENGTS OF COAX ARE NOT CORRECT
Just noticed the remake of your last gain master. I will give this a shot. Brilliant tutorial thank you
Hi,good interesting video, I have the 5/8 and the 1/2 wave Gainmaster, but good to know i can make one myself, thanks from Rotterdam.
An excellent job, Mike, so the antenna as the very detailed tutorial.
Congratulations and many thanks for the effort for spread our nice hobby!
Franc, EA6FS
You are very welcome
just made it. one adjustment and it works just fine from 26 to 29 mhz and over.
many thanks! 🙂
Excellent!
Hi Mike. I’ve made both the 1/2 and 5/8 antennas and find them to be exceptional. I was unable to locate any Westflex so used LMR 400 ultra flex with slight adjustments for the VF. 5/8 is usable from about 24 - 30Mhz.
Keep sharing antennas that really work.
73s, Mike ZL1MJB.
Excellent. Thanks sharing.
Might give this a go.
Fantastic
I have the Sirio Gainmaster 5/8 and a T2LT 5/8 and to be honest there ain’t much difference when I first tested them both in the UK
But I’m still to do a another report in my new location here in the Philippines.
Love your videos
Thanks for sharing
@@mike-M0MSN buenas, me gustaría saber si el adaptador de impedancia debe ser de bajas perdidas (wetflex o similar) o puede ser rg58, que diferencia habría de usar un cable o otro????
Great Build look like you had fun building this antenna 📡 waven four fingers and a thumb from Southern California 🇺🇸
Thanks 👍
Huh... so you use your tape measure as a soldering clamp as well ...... 😎
Nice video again Mike.
Cheers Roly
LOL me too i was just thinking the same thing.jim KB1PFL
Hi, nice to meet you! I am your loyal guardian! I’m paying attention to what you shared on the po. I’m in Taipei, Taiwan. I play CBmhz27’. I would like to ask if you have completed the trial. Do you want to sell it? I want to buy it with you for fun. I don’t know if I want to cut love. Thank you! su119.to@gmail.com Thank you for wishing you peace and happiness
ZL1BQD - Roly I am om/su119.to@gmail.com in Taipei, Taiwan
@@蘇添旺-y2t Thank you for your post. I am keeping the antenna for now.. :)
It doesn't take a lot of tweaking to get the design to cover 12m and quite a bit of the 10m SSB section within a 2:1 SWR bandwidth. Instead of the air-cored choke I use 12t on an FT240-43 toroid and it works fine - identical performance to the air-cored choke but easier to fit in a pack for portable.
Maybe you should put a video up of how you did yours or even just a graphic.
nice soldering hack with the tape measure.
Hi Mike, here is Emanuel from Campinas, São Paulo Brasil PX2 Q 1323 thanks for your videos, main to antenna gain master.
You are welcome!
Great video. Many thanks. I'll try to make this antenna myself.
Mike, really enjoyed this been watching many of your videos. Please keep them coming really enjoying your channel....
thanks Jon
It's useful if you start such videos by showing the completed antenna, so we can see how it all goes together before starting on the details. And more commentary would also be appreciated.
It would be especially useful to know the length of coax needed in advance...
And a materials list.
Nice video. Assuming the .66VF of the coax you are using, it looks like it would easily be scalable to build the whole antenna out of RG-213 mil-spec for high-power and be done with it.
Great job mike...greeting from Bali
Great job as always Mike 👍
100m drum so plenty more builds to come then 😉
Mark G6JVY oh yes...
what a money saver . and fun making to
Just built one out of old rg58 and some rg8/u for the stub
Hanging across the room the swr is pretty dead across 11m into 10m with 5w so try later today on a pole n see how it does rx against an imax if the bands are open
Rg8 is .84 so only 4 off on the velocity factor hoping it works as good
Tnx for great video
Cheers happy hombrewing
Pat ☝️💪🍻
Cheers Pat
I agree Pat. I built one out of RG-58U, including the stub and it works very well. I bought a 9.5m (31feet) Fiberglass telescoping pole and raised it. I'm Impressed.
In trying to understand the difference between the Half Wave and 5/8 of course a matching device is necessary, now I get it along with the 2TLT versions. I guess a 20 meter verson could also be figured out. The 18 meter or nearly 60 ft DX Commander pole would also make the ideal for the first antenna for a CBer, especially with the bands beginning to open up, in the states it is legal to talk to anyone you can reach so skip will be fun this sun cycle unlike my CB days when I became a Federal Law breaker LOL. We all know when that guy across the pond was heard we didn't try to make the contact. I had a contact in Rotterdam that I spoke to from my mobile many mornings working out of my car. His call was PBC123 we spoke on the slot channel below 15 and 16 in those few kcs SSB folks were stuck in 1970 or 71.
Well after watching your video two or three times I think I'm going to build a fiberglass radome from scratch on something like PVC for a former, then remove the PVC if possible
I don't know I'll have to experiment but friend of mine showed me his Station Master he picked up decades ago (Phelps Dodge is the brand) and I love it, it's about 3"- 4" diameter, except it's only 20 ft long and that wouldn't be enough to house the full size GainMaster - so I'm going to have to build one of my own.
- The idea is to make something strong enough, tough enough and stiff enough that it holds its shape atop a ponderosa pine at about 130 ft at the base.
If I can figure out a way to get it filmed and uploaded then I'll do it!
Absolute the best antenna i did make. Tnkx for sharing
You are welcome
nice idea with the tape measure
Very interesting and well worth the effort. Thanks for the video.
Thank you
Excellent job Mike... I think even I will have to have a crack at this!
Many thanks :)
Go for it, great antenna
EXCELLENT EXCELLENT EXCELLENT VIDEO!! THANK YOU!
Nice work
Thanks
I am going to have to watch it again, it looked as if you just used thick coax for the matching stub, but then I was tired at 2;30am and my brain had slowed down. I take it that there was a vast improvement, but I just watched it and it went in one side and out the other! Good video though Mike. I'll be back to watch it again this weekend. Though I can't see me getting to put it up, however, a string fired over a tree and pulled up might work ok. I think it would work well on top of a hill near me that looks south, west and east. I need to obtain a pole to try it. Nice one Mike.
nice trainers!! good videos will have to try this 1 thanks mike! 73s from wales mw0ssb
I got another pair just like them
Using the Hawkins radio 58+ Thunderbolt for a few years now .For Mobile static. Amazing results on 10 and 11 meters. On a fibre glass pole . Feed at 1.5 m extending to 10 m.. all on 100 w.
73s HS0ZOU
Nice one. Must make one soon
Nicely done!
Thanks!
Awesome stuff Mike. I use a Hawkins radio home brew 5/8 wave for field days works very well.. I have a old Rotel cb27/81 if you get the urge !! Lol... ATB ... M7AVM..
LOL, purchased a CRT today so I can play....err test the antenna fully..
Thank,s for a realy good video,i have nostalgi radio.Sommerkamp TS-288A 24Ch and i want too build this model of antenna. Thank,s again from Sweden
Thanks!
I would try to "" refurbish my spare GAINMASTER"" with
TEST WITH H155 and AIRCELL7 .. to take way more Watt..
So, it is a Bazooka basically. Great video! It would be more manageable to use a choke (toroid) over the coax balun (1:1 current), and run it inside of the tube.
Mantab...saya akan mencoba. Terima kasih 👍
Terima kasih
Very good video indeed Mike, 73s from 2W0EQQ 😃
Many thanks!
Wow so impressive. Do me one I pay yo 🤣 very nice antenna enjoy it 🙏🏻
Thanks Mike 👍
👍
Great video
Thanks!
Probably more than half the price of the Gainmaster too
Hi, thanks a lot for that great video; would be great to hear about the HowTo regarding the 5/8 wave Gainmaster. A summarized list (lenght, capacitor, stub,…) would be good. Best 73, Chris HE9MPU
Goblets good
Good tutorial.. Thumbs and 4dB (delicious bananas) up!
Thanks
Have you ever used Heat Shrink TAPE before? Really handy when tubing become awkward. There is a "glue lined" version available as well.
Send me a link Roly please
in inches yes thanks!!!
Can I also use RG214 as I dont have westflex103 available?
Hello Mike firstly great videos, learn't so much from you and Hams like yourself who make these videos to help others. I hav a question regarding the "CHOKE", 66mm is the diameter the governing factor or the length. Basically I am asking can you use another former size if that is all you have to hand, so long as the length of coax in the coil is correct. Thanks very much, keep it up.
Is it possible to only use RG-58 to build this antenna since we don't have that other cable you used for the matching stub? Thank you.
did a lot of reading & a 5/8 only gets you a extra 3dbi IF you have 120 1/2 wave radels ! with normal 3 or 4 radels you get only 1-2 db better! not worth it! love to see this agenst your 1/4 ground plane at the same hight.
Holle Mike, what size DX Comander pole did you use? I am entertaining the idea of getting a pole from Cal and building one of these for a portable work site antennas
So the base of the antenna is where the coil is? I wonder how well it would perform higher up. Cool video 👌
Time to experiment then Matt..
Fantastic AAA
Fantastic!!
Thanks!
I have all of mine constructed, just waiting on the Westflex 103 and still need some type of pole. The DX Commander is awesome but boy is it pricey.😬
My budget is cane polish.
Blade I calculated the impedance of the shunt matching section of Westflex 103 and it appears that a 127nH shunt inductor will give the same effect. I’m not an antenna guru but I have more than 30 years of RF circuit design under my belt and I’m pretty sure that it will work.
@@johangrundlingh3729 Is that like a certain length coil that could be used instead of 103?
Mine is working great with westflex 103.
1.31 ch1, 1.15 ch 20 and 1.31 on ch 40 SWR
Blade I was thinking along the lines of an air-cored solenoids inductor. A 127nH inductor could be a 4-turn coil of #18 wire wound on a 3/8” mandrel, length of coil = 3/8”. What can I say, I’m cheap...
@@johangrundlingh3729 Have you tried that? Sounds like it would be way lighter and less hassle to solder in.
It would be interesting to see the calculations it takes to figure all that out.
@Blade I’m in the process of building the antenna but I’m waiting for the fiberglass pole/mast to make it work. For the calculation I started by calculating the reactance of the shorted coax assuming losses are negligible: X=j * Zo * tan(length in degrees) and then finding the equivalent inductance from L=X/(2*pi*Frequency). I’ll let you know how it turns out when I get the mast.
Edit: I realized that I forgot to factor in the veloci factor of the Westflex 103. The recalculated shunt inductance is 150nH.
Hi Mike. I may have misunderstood. Just re read it, 72 mm matching stub...not 75ohm Ive put my glasses on...ALL coax 50 ohms ???
lol
What to do if there is no Westflex 103 cable
Rg213, MP ultraflex 10, you just need to adjust the length.
Tenho uma dúvida no stub você fecha curto solda a malha junto com o positivo...
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)))))))
Parabéns pela antena aqui Robson do Brasil aqui no Brasil só temos antena tradicional gosto muito das antenas que vcs tem aí eu gostaria de comprar uma antena dessa ou uma tram 1499 que não vende aqui valeu pelo seu trabalho pelo vídeo
Muito obrigado
Great antenna project. I have a question: how do you increase its continuous power handling? Let's say, 1000 watts. As far as I know, current gain master 5/8 is only 500 watts. Thanks.
Is there any body that builds and sells these please 🙏
Very nice. Thank you.PY2JU
Is it critical to use the quality Westflex coax? If its only a 75 ohm stub and not being transmitted through, is it that important ? It just means having to buy a 1m length, everything else I have ...Cheers Mike
p.s Any chance of a 27/28 mhz slim Jim. Its something thats always fasinated me. I ve had sucess with 2m and 70 cm but always failed on 27/28.
Whoever thought this up was genius.
Old design
But nicley build bu SIRIO.
@@kennethschultz6465 very very old design..
Hi Mike, great video, just one question if I may, I have standard RG58 but I also have some spare mini8, would it make much difference which one to use, Thanks for your time
Great video! Is this like the thunderbolt SSD?
Looking on your qrz you have a sirio gainmaster up how do these compare. ---- Update just seen this in your other videos
This is very nice Mike!😀
I'd like to have the DX pole and build the antenna.
Do you have a plan available?
Does the factory built one have the wire inside aluminum tubing?
Hi do you sell these antennas or could you make me one
Many thanks
Nope, sorry DX Commander maybe making something like them soon.
Hello, regards from Costa Rica, central america, I have a question, what will be a good substitute for Westflex 103 coax? We don't have that type of coaxial cable available in Costa Rica, what do you recommend to make the matching stub? 73s! TI2GBB -Greg
maybe 174 or LMR400
Hi Mike,what the difference from rg213 and westflex 103 for the matching stub.
Regards.
Velocity you can use RG213 or RG314, LMR400 but you will need to work out the length, start long and cut back.....
Hi Mike did it tune up straight out of the box as they say or did you have to adjust the antenna?; Looks like I've got something to play with the weekend if it will work with 213 coax thanks for the great video 👍
A little bit of fine tuning required
very nice construction and detailed explanation. I don't understand.... , confusingly in the measurement: On the RG58 measure 218.5cm/86" down from the matching stubb, and at 15:35 you say 2.26meter to the top of the coil. what is the correct measurement?
Hi many thanks, 218.5 cm is the correct measurement, the other measurements includes the height of the coil….
Thank you for your response and instructions. Do you connect the end of the westflex 103 back?
hi newbie here , what whould happen if we lengthend the feed to floor level then put radials out . just a mad thought ,
Hello from Greece!! Nice work and thank you for the video!! Working perfectly 1.0:1 26-28 mhz.. plz make a video with A99 solarcon..
I will try!
@@mike-M0MSN i will wait!! thank you for answer me..
hi mike. can you or anybody who has built the antenna clarify where the measurment starts for the top section as you cut a lenght of 345mm 1.5mm wire but the drawing you show, shows the 345mm starting from the centerpoint so it then includes the capasitor lenght. i have made this antenna this afternoon but am now unsure of the lenght of the top section or at least where to measure it from.
many thanks for making the video.
73's richard
I cut the element longer as it is easy to cut to the correct length once finished.
Hi Mike. Made this antenna but made the top section out of a piece of wire. Just wondering if the top section could be made different lengths to suit other frequencies and bands ?
You would need to scale everything. up or down to shift frequencies
Iam curious how RG-400 coax would work ???
Muito boa antena swr muito bom 👍
Ciao Mike, complimenti per il video davvero bello. Ti volevo chiedere se lo stubb va cortocircuitato perché nel video non sono riuscito a notarlo. Grazie 73
Sì, accorcio lo stub a VSWR. :)
I made the 1/2 and the 5/8 versions and had a bad coax. New coax and the thing works really well for what it is ans the cost is like nothing
So sorry to hear this. don't give up.
Great job man. Thanks to share your skill.😉 I only didn't understand why you was not able to transmit on 27 MHz without cobra. Whats is a cobra?
A CB tranceiver...
Merhaba bana Türk ce cevap verdiğiniz ve düşündüğünüz için çok teşekkür ederim 73
Excellent Mike because of my Dyslexia can you let me have a shopping list of cables used just ordered the bottle for coil looks absolutely amazing regards Adi G7MUY
Yes I can, RG58 Mil spec (14 meters ), Westflex 104 ( 1 meter length ) and a SO239
@@mike-M0MSN thanks alot keep up the great work regards Adi G7MUY
Buenas noches muy buen, video!! Mi consulta es que en centro quedo en 27800 y quiero dejarla centrada en 28200. Donde debo acortarla?
No, funcionará hasta 30Mhz.
Hello. With inspiration from your video, I want to build my own antenna. I don't have the opportunity to get Westflex 103, I only have RG213. Should the measurement on the stub still be 72 cm when I use RG213?
no, you will have to play with the lengths ( maybe shorter)
@@mike-M0MSN i made one inside a 8 meter fishing pole and the difference between my old alu 1/2 and this gain master is big. It's much better than the 1/2 vave so I'm a happy man 💪
Hi Mike !
Was Gain Master 5/8...Could you show us how to make 1/2 Gain Master ? I woud also like to do another one and try out how it works ! Thank for great video Mike !!!
Regads fan from Finland 👌
ua-cam.com/video/-0s4La1MElQ/v-deo.html
I bathed the cut in liquid electrical tape before applying shrink tubing to help increase insulating effect. 3:45
I like your trick with the measuring tape! 8:45
Actually 66mm is closer to 2.6" but I'll bet you're going to be close enough. 12:33
Boy, you really screwed up there, 'eh - lol 17:26
Sweet! and a perfect 52Ω - exactly what my home-brewed Penetrator ended up when X=0 @ 1:1 SWR
Refreshing to see a plan come together so well!
So if a touch longer then I can see a sub 2.5:1 from 12m - the top side of 10m FM!
...and I'm a little surprised you haven't modded the TS-2000 for "MARS/CAP" as we say in the USA. 19:45
Wow, I think you have said it all. Many thanks for the comments. :)
What is the difference between the westflex and the coax? Do not know where you can get westflex.
Its just another type of coax with a better power handling and VF. You can use RG58 but a shorter length and lower transmit powers
Very good video. Im a new subscriber and the questions I have are, what size DX Commander pole are you using and what size coax are you using to go to your radio? As well how are you adjusting for SWR? Thanks!
Dennis Kwasnycia Hi, the pole is a DX Commander Classic so about 9.4M, I am using Ecoflex 7 from the antenna back to the rig. There is no need to SWR if build correctly but a mixture of cutting the length (top) and matching stub. Top firstly. Cheers
how long is the 1.5mm piece looking at your diagram i think its 3.45m but it sounds like you say 1.45m in the video and have found the so239 job for weekend.
yep about that.
hi Mike, a question about this gain master project. I notice that you used an rg 58 cable (with a speed factor of 66) if I use a messi paoloni hyperflex 5 cable (with a speed factor of 87), the length of the stub always remains 345 cm after the reel? always using rg 213 for the 9pf capacitor and impedance adapter.
There is no need to use M&P you will not see any benefit, for what it's worth stick to RG58. :)
@@mike-M0MSN OK thanks . I'll do the experiment
Hi, i built this and put it on a fishing pole but the SWR is very high.
The last two sections of the pole are carbon fibre could this be the problem.
Yes, it is.