Yep that's the next project. I've built loading coils a few years back to add 80M to a 40M inverted V. 78 turns each for 2 coils worked like a champ. This little coil you did is just what I need for my SS25. Going to the hardware store tomorrow. Thanks!!
Michael, this has to be one of my top favorite videos you have done. I’ve got the Chameleon 25’ whip and I’m going to build your Magnificent 7 coil. 73, Bill KC2KNA
Great build idea. However, I’m POTA lazy. I use the CHA mini with the 25 ft whip. Hit tune and away I go. I have zero concerns about efficiency and losses. It’s been a killer combo so far. Great built quality by CHA.
You’ve always been an inspiration, Michael. Thank you for all that you do, and keep the amazing videos coming. Hope to catch you on the airwaves, and perhaps visit Wisconsin when the weather is better! Cheers and 73, KF0QNM❤
Another great video, Michael. I really like the Chameleon SS25 whip antenna. I'm adding this coil build to my project list. You are starting to become a bad influence on my pocketbook. LOL. Although this one won't cost too much since I already have this whip antenna. Keep up the great video work! 73
Great video! Just made one for myself centered on 7.175 MHz, which took 9 turns. About 45 minutes start to finish once I had all the parts. My first attempt at making a loading coil, and your description made it easy. Thanks! Any thoughts about an 80M coil???
I'm glad to hear the instructions worked well for you. I am thinking of an 80m coil. The problem is the limited bandwidth. When I use the SB1000 adjustable coil on that band, I get about 250 KHz of bandwidth with the 25 foot whip. For a fixed coil, you are going to have to pick a single frequency or small range to focus on. Since most of my 80 meter portable work is digital, I'm thinking of making a coil tuned to the 3574 KHz FT8 frequency.
@@KB9VBRAntennas Sounds good. I'm going to give it a try with an 80m coil, perhaps on at 3574 as you suggested for FT8, and another in the phone band. I've been looking into base loading coil designs and factors; it appears that a larger diameter coil can create a broader bandwidth, but I can't find much info on how much the bandwidth is affected, nor on exactly what the trade-off would be (there's always a trade-off). Some vague references to "efficiency." PVC options of ID 2", 3", and 4" in play. I'm curious what your take or decisions might be.
Glad to get you in the log. I was on the way back from HRO where I picked up a SS17 when someone text me and said I made your latest video. Little did I know it was about making a coil which I was planning to do! Keep the videos coming.
Nice video. I've been kicking around the thought of building a coil for 160m ft8 frequency, maybe as an add-on to the full size WRC I already have. High Q factor with a 17 ft whip, but it only needs to be resonant for 3kHz passband.
If I am trying to build a 1/4 wave, with a 17’ whip, can I make a sporty 40 if they aren’t selling the commercially available one? Got any material spec or info to build by?
You can. There’s a link in the video description for plans to make a coil for the 17 foot whip. The only difference is that you need 17 turns of wire on the coil
I'm already thinking about an 80m coil. The problem is the bandwidth. In using the SB1000 adjustable coil, I get about 250 KHz of bandwidth on 80 meters. You'd have to pick and choose where on the phone portion you want to be, but I think it would be perfect for CW/Digital operation.
WOW. A minimum of 1.07 @ 7.05 MHz. What does that work out to: 0.05 watts Reflected Power. No wonder everyone could hear you. Great work. You should sell them under the KB9VBR Antennas Line. Have a good one. 73 from John KK7UAG
Thanks for the URL for the calculators. Is there any particular reason why you chose 14ga wire? Was it just something you had on hand? My little brain tells me that using a thinner wire, like 16ga, would enable a person to get a closer approximation to the calculated required inductance value as the correct number of turns could be more closely achieved. Just a thought.
Hi Michael, great video! You explained the 40-meter coil construction so clearly-very helpful for future projects. Thanks for sharing! 73 de Emilio IU8QTM
Great video! You did an awesome homebrewing this coil and made it look easy. One question, all other things aside, what would be the pros/cons of using the coil with the whip vs utilizing an antenna tuner and feeding it straight to the whip?
The coil creates a resonant antenna, which means your impedance at the feedpoint will be close to 50 ohms, matching it to the feed line. As your feed point impedance increases, the mismatch creates standing waves which result feed line losses. If the feed line is relatively short, or if you are using low loss cable, you can minimize those losses, but there is still loss none the less. If you want to go the tuner route, though, the internal tuner in your rig will not have enough capacity to handle the mismatch and you will need a wide range external tuner. Or you could add a 4:1 transformer at the feed point of the 25 whip. In doing so you reduce the feed point impedance to a manageable level which minimizes losses. In doing so, you've just created the non resonant Rybakov antenna. I've get several videos showing that antenna in action.
Nice very good job, was going to say need one for 30 m but 23ft is 1/4 wave 👋 . She'll handle your power no worries. Again nice job. Could try 12ga if you want more power and efficiency
Thanks for sharing the construction, I'm wondering if I can make a JPC-7 style dipole base with a Tee piece coupler. One thing which might skew the resonance that I've seen on other similar videos is including the length of the bolts / coupler as part of the whip, Where you said you had to shorten the whip slightly you are probably adding 2 to 3" with the M10 coupler etc. Just a thought.
You could. Long before the Buddipole was a commercial success, W3FF published the plans to build your own. I built one many, many years ago and it made the trip to more than one Field Day back in the day. The plans are still floating around online, so I'm sure they could be adapted to what you are looking for: k4gar.com/wp-content/uploads/2019/01/homebrew-buddipole.pdf
I did not specifically test it with radials, but I’m confident it will work the same as the sporty forty. For that, I like to use 8 16 foot radial wires.
The reason I build the coil for the bottom of the band is that if I want to use it at a higher frequency, it is easy to bring the antenna into resonance by shortening the whip slightly. If it was built for the middle of the band, and if the SWR wasn't ideal, I wouldn't have any whip available to lengthen for resonance.
It's the Heil BM-17 dual side headset. I did a video on them a couple years ago: ruclips.net/video/qB1z2g8m090/видео.html. They are temporarily discontinued, but Heil is coming out with an improved model early this year.
Yours certainly has a much better price point than the CHA 40M-COIL which they rate at 200W SSB. I'm curious if you see any degradation at about 600W on SSB with a POTA type duty cycle. Thanks for making the video. Happy New Year. 73.
Like the Chameleon coil, this one uses 14ga enamel copper wire, so their power ratings should be quite similar. I haven't tested it above 100 watts, so I don't know what the effects will be at a higher power level. In chatting with others, it seems that using 12ga wire shoudl be enough to bring the power rating up to about 500-600 watts
@@KB9VBRAntennas Yeah, that's 2.5x less resistance per thousand feet. However, to make a high Q inductor for maximum RF emission (L/D ~ 0.45), I think I would also want to use a 1.75 inch diameter pipe (vs 1.625 inches). That would give me a coil length of 0.84 inches (L/D = 0.84/1.75 = 0.48) with 12 ga wire and 9.5 turns to get 4.4 uH. I have a CHA whip so maybe I'll give it a try. My wallet would like it better than spending $90 plus tax 🙂
Looks like you connected this to your coax with a generic mount. What are the implications of using the Chameleon Blank adaptor (perhaps no different from your setup) or then again the CHA Micro or Mini? What are the implications of using a tuner to widen your bandwidth a bit?
You could use the Blank adapter and ground spike with this coil. You'd then attach your ground radials or screen to the spike. I show this setup in my recent review of the Blank Adapter and M-Coil ruclips.net/video/vXVFVmr3yyU/видео.html. Operationally this coil is no different than the CHA M-COIL or the Sporty Forty. The only difference is that it lets you use the 25 foot whip instead of the 17 foot whip.
That should probably work. Many, many years ago I built a Buddipole using the plans that W3FF originally published. The low band coils were wound on 2 inch CPVC and he used foam pipe insulation inside the form to hold them in place on the horizontal members. A piece of foam or pool noodle could keep the coil from slipping on your crappie pole.
I've been collecting the parts to build one for my 17' whip. I've got a 2nd 17' whip and a dipole bracket coming to put the 17' whips on. Would two of these work for 40-meter dipole, one on each whip?
Hi Michael great video. Question, the PVC components look larger than 1 Inch in diameter more like 1 5/8 or 2 inch? You also reference in the on line calculator 1 5/8 diameter. On your purchase list you state 1 inch?..
Great question. The coupling is for joining 1 inch PVC pipe, so it has an inner diameter of 1 inch and an outer diameter of 1.6 inches. This is the item that I used: www.menards.com/main/plumbing/pipe-fittings/pvc-pipe-fittings/nibco-reg-socket-schedule-40-pvc-coupling/f00030t/p-1444449180118-c-8571.htm And for your reference, the plug is also labeled at 1 inch: www.menards.com/main/plumbing/pipe-fittings/pvc-pipe-fittings/nibco-reg-spigot-schedule-40-pvc-plug/f01021d/p-1444449159872-c-8571.htm
Chameleon's 40 coil rated at 200w and can be used on 30 and 60 with adjustment. When I am parked in my truck I use a tri mag mount and 40m ham stick. Do you think this will work well on mag mount (I already have the 25' whip)?
It should work fine with a mag mount, I've done similar with the Sporty Forty and 17 foot whip. There isn't any difference, operationally, between that setup and with this coil and 25 foot whip.
Mike, with the number of windings you're showing on the coil, how much wiggle room do you have with the antenna? Is it all the way up, or do you leave a little room to work with? Thanks Mike. I love my 25' whip so I'm definitely making one. 👍😀
With the whip fully extended, the antenna will resonant at the bottom of the 40 meter band. So there isn't much wiggle if the resonant point is higher and you need to extend the whip length. (This can happen with certain ground conditions where the conductivity is very poor). In prototyping the design, I made a 2nd coil with 11 turns of wire. This brought the resonant point down to 6.7 MHz. At that frequency I had to shorten the whip by one entire section to bring it into resonance at 7 MHz. I'm thinking, if I build another one, to maybe use 10 1/2 turns of wire. You may have to shorten the whip slightly depending on your operating frequency, but it would give you the headroom necessary for just about any ground condition.
No I am not. This is intended to be a resonant antenna. If you want to tweak the SWR a bit (say you were operating in the phone portion of the band), you could just shorten the whip slightly.
That's a great question and without any objective analysis, my gut feeling is that the coil and SS25 are going to be more efficient than the Rybakov on 40 meters. Rybakov performance really drops fast on 40m and below. But also the base loaded vertical's efficiency can be affected by how robust the ground network is. This may require some testing when the weather gets warmer.
Michael, this video came just in time for me. I am making a solid coil, 2 inch glass reinforced PVC, 2 mm enammeled copper, 10.75 turnss (will give me 4.1 micro Henry) , with a step between turns of 3mm. (to avoid arching, I'll explain why further). I intend to use it on a magmount (single one but big), CHA SS25, on top of my car, and operating from my caravan . I intend to use it with Acom 1010 amp, pushing 700w in it. What do you think, could be any issues with coil heating / arching?
In chatting with others, it appears that 2mm wire (12 AWG) would be sufficient to handle 500-600 watts of power. Keeping the wires separated by 3mm should further prevent arcing. My only concern would be heating, so look for a heat resistant material for your coil form.
@@KB9VBRAntennas I got the coil forms from glass reinforced plypropilene - which is mechanically more durable and can handle heat better. I ordered and got all the parts from your video delivered today . I will let you know once I will have the coil tested how it handles QRO , Also , I used those coil calculation links to set the dimensions for a 80m band coil . It's 29 microhenry . I will need a 3 inch coil for that, can be done
Michael, Two things: 1. Is there any reason you couldn't use one of those couplers and some threaded rod to extend 17 ft whip to make it 213" instead of using the little pigtail I have seen you use? 2. I know you can't answer every email. Did you ever get the email I sent you last June that had an STL for the arrow nocks to put on the end of the Tractor Supply poles for the 6M moxon? If not, I'll print you some and bring them to Orlando.
In my experience with the SB1000 coil on 80 meters, the bandwidth gets tight, about 25 KHz. That's the downside of fixed coils on the low bands. But if you only want to use it on a small range of frequencies, they are ideal. I'm thinking of making one for the bottom of the band for the digital segment.
I love when hams make things rather than simply buying something.
That’s my dads website, he’s the goat
Yep that's the next project. I've built loading coils a few years back to add 80M to a 40M inverted V. 78 turns each for 2 coils worked like a champ. This little coil you did is just what I need for my SS25. Going to the hardware store tomorrow. Thanks!!
Michael, this has to be one of my top favorite videos you have done. I’ve got the Chameleon 25’ whip and I’m going to build your Magnificent 7 coil. 73, Bill KC2KNA
Let me know how it works for you
@ will do. Perhaps I can make a QSO with you on it. I can hear you here in NY most of the time when you are doing POTA.
Great job! Love the idea to get the full length out of the SS25!
It's the frugality of the Midwest. Leave no whip length wasted.
Great build idea. However, I’m POTA lazy. I use the CHA mini with the 25 ft whip. Hit tune and away I go. I have zero concerns about efficiency and losses. It’s been a killer combo so far. Great built quality by CHA.
Nothing wrong with that, there's all sorts of different operating styles.
You’ve always been an inspiration, Michael. Thank you for all that you do, and keep the amazing videos coming. Hope to catch you on the airwaves, and perhaps visit Wisconsin when the weather is better!
Cheers and 73, KF0QNM❤
Thanks for the support, I really appreciate it. If you are ever in the State, drop me a message.
Another great video, Michael. I really like the Chameleon SS25 whip antenna. I'm adding this coil build to my project list. You are starting to become a bad influence on my pocketbook. LOL. Although this one won't cost too much since I already have this whip antenna. Keep up the great video work! 73
If you like the 40 meter band, you'll love this little project.
The Shorty-Forty!
Great video! Just made one for myself centered on 7.175 MHz, which took 9 turns. About 45 minutes start to finish once I had all the parts. My first attempt at making a loading coil, and your description made it easy. Thanks! Any thoughts about an 80M coil???
I'm glad to hear the instructions worked well for you. I am thinking of an 80m coil. The problem is the limited bandwidth. When I use the SB1000 adjustable coil on that band, I get about 250 KHz of bandwidth with the 25 foot whip. For a fixed coil, you are going to have to pick a single frequency or small range to focus on. Since most of my 80 meter portable work is digital, I'm thinking of making a coil tuned to the 3574 KHz FT8 frequency.
@@KB9VBRAntennas Sounds good. I'm going to give it a try with an 80m coil, perhaps on at 3574 as you suggested for FT8, and another in the phone band. I've been looking into base loading coil designs and factors; it appears that a larger diameter coil can create a broader bandwidth, but I can't find much info on how much the bandwidth is affected, nor on exactly what the trade-off would be (there's always a trade-off). Some vague references to "efficiency." PVC options of ID 2", 3", and 4" in play. I'm curious what your take or decisions might be.
Glad to get you in the log. I was on the way back from HRO where I picked up a SS17 when someone text me and said I made your latest video. Little did I know it was about making a coil which I was planning to do! Keep the videos coming.
I'm glad to get you in the log that evening. Let me know how your coil works out.
Nice video thanks for showing the step-by-step instruction on building the coil and providing links for the coil. Inductance calculator.
The site is amazing, I know the man who runs it and he is very thorough
Nice work and it looks like a project even I could tackle
At the very least, it's a good reason to go out and spend money on hand tools.
Fantastic video Michael with a combo of commercial whip and homebrew coil, very nice!
Again, great home brew, Mike
Nice video. I've been kicking around the thought of building a coil for 160m ft8 frequency, maybe as an add-on to the full size WRC I already have. High Q factor with a 17 ft whip, but it only needs to be resonant for 3kHz passband.
Yet another awesome video, and very timely for me!! Thanks so much!!
Thanks!
Thank you so much for your support, I really appreciate it.
Thanks Michael! Another great video. I really appreciate your sharing your experience and knowledge. Your a great Elmer! 73.
MAN! Who'da thought it would be so hard to find 1" PVC pieces parts. The big 3 (orange, blue, and ace red) none had the 1" plugs. Sheesh.
Top shelf sir! Great content!
Thank you. I needed a project and a beautiful and useful one it is.
Great video! Thanks for the very clear instructions!
Great video. Thanks, Mike.
I’m so going to make one of these. Tried for months to buy one from WRC, but they didn’t have any. Finally gave up. Thanks for this one Michael!
I guess WRC is finally open again, but they probably have a backlog of orders to work through. Let me know how this works for you
Great video! I really need to get this whip and built the coil. I use mostly EFHW, and have a JPC-12, but really want to try a long whip.
If I am trying to build a 1/4 wave, with a 17’ whip, can I make a sporty 40 if they aren’t selling the commercially available one? Got any material spec or info to build by?
You can. There’s a link in the video description for plans to make a coil for the 17 foot whip. The only difference is that you need 17 turns of wire on the coil
Congrats Michael! Very impressive. I love DIY things that work! Now, what about an 80m coil for the 25 ft.?????
I'm already thinking about an 80m coil. The problem is the bandwidth. In using the SB1000 adjustable coil, I get about 250 KHz of bandwidth on 80 meters. You'd have to pick and choose where on the phone portion you want to be, but I think it would be perfect for CW/Digital operation.
WOW. A minimum of 1.07 @ 7.05 MHz. What does that work out to: 0.05 watts Reflected Power. No wonder everyone could hear you.
Great work. You should sell them under the KB9VBR Antennas Line.
Have a good one.
73 from John KK7UAG
Thanks for the URL for the calculators. Is there any particular reason why you chose 14ga wire? Was it just something you had on hand? My little brain tells me that using a thinner wire, like 16ga, would enable a person to get a closer approximation to the calculated required inductance value as the correct number of turns could be more closely achieved. Just a thought.
Hi Michael, great video! You explained the 40-meter coil construction so clearly-very helpful for future projects. Thanks for sharing! 73 de Emilio IU8QTM
Great video! You did an awesome homebrewing this coil and made it look easy. One question, all other things aside, what would be the pros/cons of using the coil with the whip vs utilizing an antenna tuner and feeding it straight to the whip?
The coil creates a resonant antenna, which means your impedance at the feedpoint will be close to 50 ohms, matching it to the feed line. As your feed point impedance increases, the mismatch creates standing waves which result feed line losses. If the feed line is relatively short, or if you are using low loss cable, you can minimize those losses, but there is still loss none the less.
If you want to go the tuner route, though, the internal tuner in your rig will not have enough capacity to handle the mismatch and you will need a wide range external tuner.
Or you could add a 4:1 transformer at the feed point of the 25 whip. In doing so you reduce the feed point impedance to a manageable level which minimizes losses. In doing so, you've just created the non resonant Rybakov antenna. I've get several videos showing that antenna in action.
What tripod is that?
The Mighty Michael forty coil
will be making this soon. and I'm the same way have to call QRT and turn the radio down or off right away because people will still keep calling.
Awesome, thank you
Nice very good job, was going to say need one for 30 m but 23ft is 1/4 wave 👋 . She'll handle your power no worries. Again nice job. Could try 12ga if you want more power and efficiency
I am thinking of a 60 meter coil, it should have enough bandwidth to cover all five channels
와!!! 감사합니다, 잘 봤어요,,
Thanks for sharing the construction, I'm wondering if I can make a JPC-7 style dipole base with a Tee piece coupler.
One thing which might skew the resonance that I've seen on other similar videos is including the length of the bolts / coupler as part of the whip, Where you said you had to shorten the whip slightly you are probably adding 2 to 3" with the M10 coupler etc. Just a thought.
You could. Long before the Buddipole was a commercial success, W3FF published the plans to build your own. I built one many, many years ago and it made the trip to more than one Field Day back in the day. The plans are still floating around online, so I'm sure they could be adapted to what you are looking for: k4gar.com/wp-content/uploads/2019/01/homebrew-buddipole.pdf
Michael, did you use any radials? If so how long and how many? Thanks for the video!
He used the faraday cloth “magic carpet” probably
I did not specifically test it with radials, but I’m confident it will work the same as the sporty forty. For that, I like to use 8 16 foot radial wires.
Great build, try it at a midpoint coil with 25' total length.
The reason I build the coil for the bottom of the band is that if I want to use it at a higher frequency, it is easy to bring the antenna into resonance by shortening the whip slightly. If it was built for the middle of the band, and if the SWR wasn't ideal, I wouldn't have any whip available to lengthen for resonance.
@@KB9VBRAntennas I ment high up on the antenna not the band.
EXCELLENT VA2SOB Claude
Michael, this is incredible. May I know what headphones- mic are you using, they look trendy, indeed!
It's the Heil BM-17 dual side headset. I did a video on them a couple years ago: ruclips.net/video/qB1z2g8m090/видео.html. They are temporarily discontinued, but Heil is coming out with an improved model early this year.
Excellent. A diy band coil. 👍x 2
Yours certainly has a much better price point than the CHA 40M-COIL which they rate at 200W SSB. I'm curious if you see any degradation at about 600W on SSB with a POTA type duty cycle. Thanks for making the video. Happy New Year. 73.
Like the Chameleon coil, this one uses 14ga enamel copper wire, so their power ratings should be quite similar. I haven't tested it above 100 watts, so I don't know what the effects will be at a higher power level. In chatting with others, it seems that using 12ga wire shoudl be enough to bring the power rating up to about 500-600 watts
@@KB9VBRAntennas Yeah, that's 2.5x less resistance per thousand feet. However, to make a high Q inductor for maximum RF emission (L/D ~ 0.45), I think I would also want to use a 1.75 inch diameter pipe (vs 1.625 inches). That would give me a coil length of 0.84 inches (L/D = 0.84/1.75 = 0.48) with 12 ga wire and 9.5 turns to get 4.4 uH. I have a CHA whip so maybe I'll give it a try. My wallet would like it better than spending $90 plus tax 🙂
Looks like you connected this to your coax with a generic mount. What are the implications of using the Chameleon Blank adaptor (perhaps no different from your setup) or then again the CHA Micro or Mini? What are the implications of using a tuner to widen your bandwidth a bit?
You could use the Blank adapter and ground spike with this coil. You'd then attach your ground radials or screen to the spike. I show this setup in my recent review of the Blank Adapter and M-Coil ruclips.net/video/vXVFVmr3yyU/видео.html. Operationally this coil is no different than the CHA M-COIL or the Sporty Forty. The only difference is that it lets you use the 25 foot whip instead of the 17 foot whip.
Wonder how a coil that would slide over a 8m crappy pole or similar and use wire as radiator and a couple elevated radials.
That should probably work. Many, many years ago I built a Buddipole using the plans that W3FF originally published. The low band coils were wound on 2 inch CPVC and he used foam pipe insulation inside the form to hold them in place on the horizontal members. A piece of foam or pool noodle could keep the coil from slipping on your crappie pole.
I've been collecting the parts to build one for my 17' whip. I've got a 2nd 17' whip and a dipole bracket coming to put the 17' whips on. Would two of these work for 40-meter dipole, one on each whip?
I don't see a reason why not. My only concern would be the physical stress on the coil itself. I'd make sure the pieces are all well glued together.
Hi Michael great video. Question, the PVC components look larger than 1 Inch in diameter more like 1 5/8 or 2 inch? You also reference in the on line calculator 1 5/8 diameter. On your purchase list you state 1 inch?..
Great question. The coupling is for joining 1 inch PVC pipe, so it has an inner diameter of 1 inch and an outer diameter of 1.6 inches. This is the item that I used: www.menards.com/main/plumbing/pipe-fittings/pvc-pipe-fittings/nibco-reg-socket-schedule-40-pvc-coupling/f00030t/p-1444449180118-c-8571.htm
And for your reference, the plug is also labeled at 1 inch: www.menards.com/main/plumbing/pipe-fittings/pvc-pipe-fittings/nibco-reg-spigot-schedule-40-pvc-plug/f01021d/p-1444449159872-c-8571.htm
Chameleon's 40 coil rated at 200w and can be used on 30 and 60 with adjustment. When I am parked in my truck I use a tri mag mount and 40m ham stick. Do you think this will work well on mag mount (I already have the 25' whip)?
It should work fine with a mag mount, I've done similar with the Sporty Forty and 17 foot whip. There isn't any difference, operationally, between that setup and with this coil and 25 foot whip.
Mike, with the number of windings you're showing on the coil, how much wiggle room do you have with the antenna? Is it all the way up, or do you leave a little room to work with? Thanks Mike. I love my 25' whip so I'm definitely making one. 👍😀
With the whip fully extended, the antenna will resonant at the bottom of the 40 meter band. So there isn't much wiggle if the resonant point is higher and you need to extend the whip length. (This can happen with certain ground conditions where the conductivity is very poor). In prototyping the design, I made a 2nd coil with 11 turns of wire. This brought the resonant point down to 6.7 MHz. At that frequency I had to shorten the whip by one entire section to bring it into resonance at 7 MHz. I'm thinking, if I build another one, to maybe use 10 1/2 turns of wire. You may have to shorten the whip slightly depending on your operating frequency, but it would give you the headroom necessary for just about any ground condition.
@@KB9VBRAntennas Excellent. . I'm going to go with 10.5 turns. Thank you so much Michael. 😊
Are you using an antenna tuner with your home brew coil???
No I am not. This is intended to be a resonant antenna. If you want to tweak the SWR a bit (say you were operating in the phone portion of the band), you could just shorten the whip slightly.
Which set up do you think would be more efficient with the SS25 on 40? This new coil you made or the rubikov method with the 4:1 UnUn?
That's a great question and without any objective analysis, my gut feeling is that the coil and SS25 are going to be more efficient than the Rybakov on 40 meters. Rybakov performance really drops fast on 40m and below. But also the base loaded vertical's efficiency can be affected by how robust the ground network is. This may require some testing when the weather gets warmer.
Michael, this video came just in time for me. I am making a solid coil, 2 inch glass reinforced PVC, 2 mm enammeled copper, 10.75 turnss (will give me 4.1 micro Henry) , with a step between turns of 3mm. (to avoid arching, I'll explain why further). I intend to use it on a magmount (single one but big), CHA SS25, on top of my car, and operating from my caravan . I intend to use it with Acom 1010 amp, pushing 700w in it. What do you think, could be any issues with coil heating / arching?
In chatting with others, it appears that 2mm wire (12 AWG) would be sufficient to handle 500-600 watts of power. Keeping the wires separated by 3mm should further prevent arcing. My only concern would be heating, so look for a heat resistant material for your coil form.
@@KB9VBRAntennas I got the coil forms from glass reinforced plypropilene - which is mechanically more durable and can handle heat better. I ordered and got all the parts from your video delivered today . I will let you know once I will have the coil tested how it handles QRO , Also , I used those coil calculation links to set the dimensions for a 80m band coil . It's 29 microhenry . I will need a 3 inch coil for that, can be done
is there one for the 20m band
You don’t need a coil for the 20 meter band, the whip is long enough. Just shorten it to about 17 feet and it will be a true 1/4 wave radiator.
Nice!
Michael,
Two things:
1. Is there any reason you couldn't use one of those couplers and some threaded rod to extend 17 ft whip to make it 213" instead of using the little pigtail I have seen you use?
2. I know you can't answer every email. Did you ever get the email I sent you last June that had an STL for the arrow nocks to put on the end of the Tractor Supply poles for the 6M moxon? If not, I'll print you some and bring them to Orlando.
Yea....your on Rib mountain. The highest point in Wisconsin.
Third highest point in the State, but with the tallest height above average terrain.
😎👍
Great project! About $35 worth of parts, not bad, but then I need to buy a $100 whip 😢😢
Got a tree and 25ft of wire?
You could use wire. The chameleon whip is worth the investment, though. There are lots of antenna styles you can do with it
@@forgetyourlife I had a similar thought, but using one of my bigger masts. Might try an 80m coil which looks to be 25.5 turns.
In my experience with the SB1000 coil on 80 meters, the bandwidth gets tight, about 25 KHz. That's the downside of fixed coils on the low bands. But if you only want to use it on a small range of frequencies, they are ideal. I'm thinking of making one for the bottom of the band for the digital segment.
@@KB9VBRAntennas Good to know, I thought that might be the case.
I really like your coat next time I see you at a swap meet I'm going to ask you just so you know
Thank you. It’s all wool so it is quite warm, even in these bitter cold temps
@@KB9VBRAntennasAnd it goes well with the Stomy Kromer cap you usually wear.
Cha will make one eventually and charge $300 for it 😂
Im not paying 100 $ for a coil. Biden is gone. Lets make sense again 😂
bless your heart
Honestly, a coil is never a game changer. It may help people with limited space, but it comes with a lot disadvantages.
What disadvantage are those? Radiation pattern?
@@jolebole-yt Michael discusses this at 14:30 on the video.