Ham Radio Building the small Magnetic Loop Antenna

I build the small magnetic loop antenna I designed back in March of 2023. It's a long one.
Here's the link to the 3D printed part the coaxes are tied to.
www.thingivers...
The tool I showed is called a "Pin Vise". Here's a link to a search on Amazon for similar tools.
www.amazon.com...
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[@inebgreen]

Wonderful to see you back! I built my own magloop and used your videos and testing and part of my final design. Small trimmer cap to help fine-tuning was a great add-on for my antenna.

[@DXCommanderHQ]

Kevin, not watched yet - but I'm so pleased you have the energy to put this together..

[@Bill-HRT]

Glad you’re back at it! You have been one of my KZbin Elmers since I started. I’ve learned a lot. Sometimes what I’m learn I don’t use for a while, but it’s there. Get better! 73 de Bill

[@michaeledmonds3027]

You remain my favorite ham instructor, Kevin. Thanks so much for another great video. In case I missed it, it would be fun to get a tour of your RV, showing how you laid out your radio/work area while keeping a small kitchen, bath, storage, and sleeping area. This must be similar to a small ocean-going sailboat. Here's hoping for your continued health. Michael

[@loughkb]

Thanks Michael. I did a video a long time ago showing the desk I built in place of the two bench dinette that was originally in here. kzbin.info/www/bejne/oJvHimNpms-hm5I&pp=ygUSa2V2aW4gbG91Z2hpbiBkZXNr

[@johnrees44..G4EIJ]

Hi Kevin..Another great video..but more importantly..so good to see you back and looking so well..Take care..73 from the UK..John..G4EIJ

[@michaeledmonds3027]

Thanks for the work area tour, I'm not sure how I missed it. Again, so glad you're on the mend. Take good care, 73.

[@Oodle-ox2vf]

You are looking much better Kevin, good to see. I am a subscriber, I just logged in on the wrong name. 🙂 This is what Hams are supposed to be doing, experimenting, learning, and sharing. And never worry about negative comments. Heck, I am a Pro, and Amateur of 60 years experience, I even owned an aerial factory last century, and I still use tape, trash, and cable ties to test stuff. I used to get flamed by the "experts" all the time before I quit the web, who cares? Happy days ahead, keep smiling.

[@kgrafton4582]

Glad to see the video Kevin, enjoyed seeing you build something again. Keep’em coming. Praying you get back to where you were before your illness soon, God bless!

[@acestudioscouk-Ace-G0ACE]

Good to see you back Kevin and hope your recovery continues long term. Thanks for the video, some great ideas and makes me think that a loop like this is a must for a travelling ham.

[@reedreamer9518]

I love to see mag-loop projects like this - can't wait to see the next iteration. Recently I built a mag-loop optimized for 10m, but this time I built it "military style" using three capacitors instead of one (1 duel-gang & 1 single). This eliminates any exciter loop or gamma match by connecting the loop directly across a duel-gang capacitor, with the feed point and third cap connected in series across one side of the duel-gang. This allows much more precise tuning because the duel-gang functions as rough tuning and the third cap works as fine tuning.

[@loughkb]

I have a commercial loop that I recently bought that uses that arrangement that I'm going to be doing a review of.

[@reedreamer9518]

@@loughkb Nice - I look forward to seeing that. ; )

[@Rubedo777]

Hi there… sounds a really good idea you have… I may have missed it if you’ve uploaded your build… but would you consider doing a build vid please.73. 💙

[@reedreamer9518]

@@Rubedo777 I'd like to do some videos of my builds in the future, but right now I'm busy moving to a different QTH. I also have a super-efficient 2m diameter double mag-loop for 80m thru 20m with MCU based auto-tuner and 2-axis rotor - maybe someday I'll do a vid on that one too.

[@M7XCB]

Great seeing you back in RV and back your old self and lots off people have miss you on here. Will definitely have a go making loop antenna. Thanks for the video.

[@jorgeequihua5159]

Very impressive Kevin! I am glad to see you back. Take it easy so you recover fully. 73s.

[@youtubeaccount931]

Great work! I've never built one but it seems like an antenna every ham should build.

[@patrick4228]

It gives me great pleasure to see a new video from you. I assume/hope you are on the mend!

[@dbuckter8994]

Awesome job Kevin. Most helpful. 72, W6BOW

[@elmofeneken4364]

Enjoyed watching this video. Well done!

[@migsvensurfing6310]

Loop antennas are awesome. Good to see you working on the hobby again.

[@edbeckerich3737]

Glad your strength is returning!! Great video on hand held loops too!!

[@TheHeff76]

Well done and thanks for the knowledge! Looking better! Hope you're back to 100% soon!

[@jonpsimpson]

Great to see you back at the bench.

[@NU6W]

So great to see you back, Kevin! I've learned so much from your videos.

[@Steve-GM0HUU]

👍Thank you for video Kevin. Wondering about the low Q conern, a couple of things come to mind. It may be due to DC resistance. However, your design seems to be good in terms of minimising resistance. One other thing I found with loops I made is the shape of the small loop and how it is coupled to the larger loop. Changing the shape of the small loop to more of a horizontal oval shape and making sure the top half of the oval was very close to the large loop is what generally worked for me. This kind of made sense as you would expect narrow bandwidth high Q transformers to have close coupling. Rather than use co-ax for the small loop I have used things like stout copper wire or even car copper/brass brake pipe so that I can bend it into shape that works best. Great thing about the VNA is you can see the results as you try different things.

[@py1fw]

Steve bom dia nas minhas loops achei o melhor ponto no loop menor próximo ao loop menor , uso cabo rg213 para loop menor também veja lá no meu canal py1fw sou amante de magloop ,faço pile up e contest com ela tenho vários vídeos, abraço.

[@loughkb]

I actually have a video on squashing the coupling loop up against the main loop and the improvement that it makes. And I've used different conductors for the coupling loop as well. I'll make modifications.

[@Steve-GM0HUU]

​@@loughkbApologies. I found the video you made 6 years ago. I even watched it 3 years ago. My memory is not what it used to be!

[@normk7nwf323]

Kevin, as usual another interesting video. You never let us done. Keep up the great design and testing. Looking forward to more videos. Best of health of to you my friend! 73 from AZ

[@bassmanjr100]

Glad you are feeling better. Keep on moving is all you can do. I'd like to see a couple things if I made my own loop. Get as close to 20w as possible so I could use my G90 and cover 40-10m. I've seen someone use foil tape over PVC for the big loop which looked interesting.

[@2852GUS]

NIce loop, light, small and very portable. Glad you are back!

[@lilblackduc7312]

Outstanding! The 'Old Master' of magnetic loop antennas condenses tips, tricks, ins & outs and years of experience of "Try, Fail, Learn, Repeat" in a single half hour tutorial. Guard your health and "Keep the Faith", Kevin. Thank you...🇺🇸 👍☕

[@sandyjohnston9457]

Good to see you’re at it again. Good health to you. 73 from NZ. ZL3AXL

[@LB5JJ]

Good to see you back in action Kevin! Looking forward to many more videos!

[@Don-ev5ov]

Your videos are always interesting. I watched your earlier video. Loop antennas are fascinating. I watched Jeri Ellsworth’s loop build and listened to John Portune’s podcast on loops. I may try a simple receiving loop myself. Grew up in NM near Shiprock and CO. Visited AZ frequently. Good to see you back.

[@Swamp-Fox]

Nice. I have always wanted to build a small mag loop. I may just have to give it a go. 73, Patrick KF4LMZ

[@deankq4adj125]

Excellent instructional video, really enjoy your content!

[@fotografm]

Great design ! Keep up the good work, Kevin !!!

[@hectorpascal]

Great to see you're well enough to get some more projects under way - but don't overdo things,

[@MI7DJT]

I'd take some of the plates out of the variable capacitor and put spacers in to allow for more power. My 2E0ERO Magloop has 11 outer and 10 inner plates with 5-6mm spacing and it puts out 30W without issue. Love your build though wih just a single outer loop Kevin. I made a contact with Russia a couple of weeks ago from Northern Ireland with my magloop sitting on my coffee table hihi. They REALLY are a beautiful antenna, tuning is very narrow so it cuts down noise so well. Sending prayers for your good health and full recovery. God bless Kevin.

[@JT-py9lv]

I saw a video where the guy used a coat hanger for his coupling loop. Worked fairly well.

[@503Nick]

Very cool. I may need to try building a mag loop

[@shakymedia_UK]

Hi Kevin, I enjoyed this video as I’m thinking of building a loop for portable. It was also useful your comments about long Covid. I’m week 9 now after getting Covid and have some of the symptoms you describe. It’s a struggle but like you we battle on. 73’s John GM0MST

[@tropenband]

I run nearly the same setup, FT-817ND with a (slightly bigger) DIY loop, that also works on 7 MHz. Tuning is really easy and intuitive, seems that more people can hear me than whit my 20m EFHW vertical setup.

[@ralphbeardmore9738]

Wow, you sound so much better. We've all been worried about you. Thanks for making another great video. Take car Kevin.😅 M0RLF UK

[@thermicdude9164]

Hello Kevin. I use an almost identical capacitor and it copes with 20W SSB with no issues. I wire the two plate banks in series.

[@loughkb]

Yep, in the design video I talked about getting the double ganged tuning capacitor and wiring one side of the loop to each of the static plates. That way hand capacitance is far less of a factor when you're tuning it.

[@thermicdude9164]

@@loughkb I also use a "different" method of coupling to the loop - not sure how to share it with you?

[@MiddletonGuitars1]

Good to see you back at projects. I'm wondering if the shape of the outer loop might be affecting the efficiency. The bottom is looking a slightly triangular as the coax has to make a sharp turn to connect to the capacitor. Since you're 3D printing the capacitor box again, maybe you could try altering the design slightly by turning the RF connector mounting positions so that the ends of the coax loop will pass through the variable capacitor at an angle that more naturally forms a loop.

[@loughkb]

A slight deformation doesn't really make much difference if any.

[@rv6amark]

Good video, Kelvin. The best part was that you look good, although I could tell that fatigue is still a factor. I assume you shot this in many short segments. Fatigue was the symptom that was most difficult for me to shake, and is still a problem at times. -- Mark, KE6BB

[@loughkb]

Oh yeah, this video was shot over the course of an entire week. I can only do a little bit in the mornings. But it's slowly getting to be more.

[@kit121]

Nice to see you again, hope you feel better soon, thanks for your footage it is great, i'm new on the HF and definitely will try this, your video help me alot. Thanks. Thanks. Thanks ....... 73 from asia.

[@PERVISJAYFURLONG]

Glad you're back mate!

[@mickgatz214]

I had something very similar to that, back in the 80s'(minus the variable cap)... 👍

[@JohnBr1234]

That looks like a fun project. I have been wanting to try a loop antenna but did not want to pay the premium prices I see manufacrures charging. Checking my junk box, it looks like I may have all the parts.

[@petermichaelcapani7253]

Thank you for all of your informative videos. They are priceless! AC5MF

[@MegawattKS]

Thanks. Good build. I'm wondering if the SWR is actually better on the low end than the readout suggests at 20:27 . It says 2.72, but the SWR curve is very 'pointy' due to the frequency step size in the sweep. Have you tried zooming in the sweep in this frequency range to get more resolution, steps? I wouldn't be surprised if the actual VSWR is under 2:1 or even better at the bottom of the dip. Regardless, gotta love small loops ! Thanks again. 73

[@chrisherd991]

Hi Kevin welcome back, you sound a lot better than last time. Thanks for the walk through of your design, it will be very helpful in my mag loop build.

[@mariofachinsky5639]

Cool, Im about to build mine soon. Have you tried the outer shield only version? although shorting the coax gives lower resistance Im not sure how the RF radiated from the inner conductor interacts with the RF radiated from the outer one... so that would be an interesting comparison. Also it would be intersting to try a small gap on the outer conductor at the top of the main loop while using only the inner conductor to see if you get any less noise, as the antenna will act as a shielded loop... Finding a beacon will help in testing... Congratulations for your videos, very well produced and instructive, I love your contents! Best 73 from Argentina, LU2AW, Mario.

[@Rubedo777]

Hello Kevin, I enjoy your vids you have a nice presentation style. Don’t apologise for long videos when doing a build because those who have not built something but want to try need as much instruction as you can give. Mag loops are of interest as my back garden ( yard ) is absolutely tiny, really. ‘ Heartless comments “ making comments, yes, there is an evilness about this life form that gives them delight in trying to discourage and stumble their fellow man, demons. Health issues, I have quite a few and there are days where you just can’t get going and get anything done, you can just manage to make a brew and get back in bed, really frustrating and we know about your battles as many have similar experiences 🤢… I like how you can take off in your mobile home too. It’s a long fight against the likes of Covid and other conditions but keep going as much as you can without adding to that issue. I’ve subscribed 😉… Best wishes.73. 💙

[@MrApolloTom]

Thanks for the design Kevin and glad you're back building stuff. I think you will struggle QRP on 20 m with this one due to the efficiency being under 10% at that frequency for these dimensions. On 10 you should have about 50% efficiency though so hopefully you'll have more luck higher up. Have you looked at the Porton design using aluminium foil around a thicker diameter pipe? Someone on Facebook quite forcefully told me that the correct orientation is to have the capacitor on the top. There seems to be some disagreement about this, so wondering if you've found any difference?

[@loughkb]

I've built them both ways, cap on top and on bottom. I haven't been able to notice any difference in performance. The radiation pattern is a doughnut shape regardless. But some people can be quite opinionated. I usually ask them to provide the data their opinion is based on. They never seem to be able to do so.

[@KennethScharf]

That looks like a dual gang 365pf TRF receiver capacitor. I'm assuming you are using the two sections in series as sort of a butterfly cap, IE connections to the loop via each of the stator terminals, one for each gang, and the rotor terminal (frame) is 'floating'. That sorta doubles the voltage rating of the capacitor.

[@loughkb]

Yes that's how we discussed it in the design video. It also virtually eliminates the effect of hand capacitance when tuning.

[@ElbaSatGuy]

Good video, Kevin. Curious what VNA you used; the tablet interface got my attention.

[@loughkb]

miniradiosolutions.com/minivna-pro/

[@johnwest7993]

The capacitor's contact resistance may be hurting your Q. That's why butterfly air-variables are so popular. But they aren't cheap.

[@loughkb]

If you watched the design video you'd see that we were wiring the capacitor up using the static plates to each side of the loop so the gang plates become two capacitors in series And we don't rely on the contacts. This also practically eliminates hand capacitance as an issue when tuning.

[@johnwest7993]

@@loughkb, thanks for clarifying that for me.

[@johnsonstechworld]

The metal gang capacitor in your intro brought back nostalgic memories of my days of homebrewing 3 x 807 vacuum tube radio. I could work good DX on CW, including some from US on 40m. That is a performance I have not been able to repeat with my current FT-710 radio, may be because of change in band conditions and operator preferences. But the gang capacitor which you have shown is way different, with a couple of SO 239 connectors on either side. I have not seen such a gang capacitor. 73 de Jon, VU2JO.

[@loughkb]

It wasn't made like that, I put it together like that for the loop. Go back and watch the design video that I reference. I talk about how I'm wiring up the capacitor and why.

[@johnsonstechworld]

@@loughkb Thank you. 73

[@carl-gunnarhillefors7612]

AMAZING ENGINUITY KEVIN! 73s de Gunnar sm6oer >>\

[@kirklunsford7530]

Thank you for sharing. This is a new Endeavor for me and I have barely gotten my feet wet. I know long covid and would feel remiss if I did not suggest looking into lion's mane and my confidence in HOST DEFENCE products.

[@loughkb]

Very mixed results with lion's mane among the people over on the COVID long haulers forum on Reddit. There's also a subreddit for people that were injured by it. Some were made much worse, some were made better. Believe me, I have researched just about everything.

[@netfixr1]

So glad to see you back Kevin you have been missed you are one of my favorites for sure - Stellar job on the video as usual and best of health to you going forward - 73

[@theoview]

Thanks Kevin!! 73 Theo pa0hty

[@paulstubbs7678]

11:07 also known as a 'pin vice'

[@lariroli]

Super.

[@lilblackduc7312]

Quick question: If you were using a larger variable capacitor which had more room between the 'plates', is it possible to insulate against arcing ⚡between the plates by applying a spray coating, paint-on dip, or Kapton tape?

[@loughkb]

I cannot answer that question, I do not know. I have never seen a variable capacitor with any kind of a coating on the plates commercially, so I don't know that there is a better insulator than air for RF voltage

[@lilblackduc7312]

@@loughkb Thank you! If you don't know, I ain't gonna try it. Lol

[@kd5inm]

I am thinking maybe "lack of air" would be a better insulator as in or refering to a vacumn capacitor that exists inside a vacumn tube type atmosphere or "non atmosphere" that some mag loops have used. I have particular big air variable cap that I have been saving back for a big loop I might build one day. I was thinking perhaps build it and turn it horizontally and put it higher up in the air to radiate omni-directional in a non portable configuration. Good video and question gentlemen!

[@oobihdahboobeeboppah]

Hey Kevin, was it raining during the video? It sounded like rain on a RV roof between your speaking segments.

[@loughkb]

Nope, no rain.

[@KingJesusSavesSinners]

Thanks Kevin... Got the parts to make one of these and I should stop making excuses and get it done. Had a though to make you man portable a little more stable and require less attention... Make a "staff" out of PVC or something to hold the loop up and use it as a walking stick. Could even mount or strap your QRP rig to it. I would allow you to hold it up higher and away from you as well. Mike KJ4LG

[@loughkb]

That would be a pretty top heavy staff. Wobble around a lot too. I would probably get some pretty interesting looks though. It would look like some kind of strange Gothic religious icon.Ha!

[@KingJesusSavesSinners]

@@loughkb do you watch "Stargate SG-1"? If you're already running around with a magloop it's too late to worry about what you look like...

[@OE8ZZZ]

Great video! Could you explain the connections on this capacitor? This things are labeled with two values (for example 2 x 320pF / 12pF). I built one but I cannot find resonance points with low SWR. Thank you

[@loughkb]

It was discussed in the design video I suggested you watch at the beginning of the video.. The connections are each side of the loop goes to one set of static plates.

[@OE8ZZZ]

@@loughkb I checked everything multiple times but I do not have peaks with a good swr. I had not much time but I will try again on tuesday. The capacitor works fine and I have a range between 0 and ~176pF. I'm using a double capacitor like in your video and I connected the ends of the coax to the stator connections (SO-239 are shortened like in your video). I originally built this antenna last year with another capacitor and I wanted to give it a try so I bought a new capacitor but with the same results...

[@loughkb]

No variable capacitor will ever go down to zero. My email is good on QRZ, email me pics of your capacitor connections and of your coupling loop connections.

[@OE8ZZZ]

Thanks! I will do so on Tuesday when I‘m back from work. Appreciate your help! 73 Patrick

[@JeffreyWilliams-x4x]

Sure glad you are back you are a great teacher 73 kd2vrz

[@andrewandrosow4797]

Hello!A capacitor from tube radio can not working in transmitter mode. There will be electrical sparks between plates.Ihave similar capacitor but when I turn on a1W transmitter - the plates shortes unexpectedly.

[@loughkb]

I have run 5 watts CW with no arcing. I don't think I can get much higher than that. In your case, there might have already been a defect or a bent plate?

[@ciphernaut]

Can one use a spark plug set to a gap smaller than the plate spacing and parallel to the cap to protect it from arcing?

[@loughkb]

I'd be a little more worried about the transmitter. You want to just avoid arcing in the first place because that kickback can cause extremely high spikes in SWR and possibly damage the finals on the radio. So it's best just to keep the power at safe levels.

[@glowlair-vg7we]

Good to see you back. I killed my old page. I'm back and subbed to you alone. Do you know anyone that does open source digital reflectors with open source on raspberry pi's? Thanks Kevin

[@loughkb]

Nope, sorry I have not looked into that.

[@jacobboth1438]

The bandwidth of your loop at 14 MHz is the same as your CHAMELEON CHA P-LOOP 2.0 at 14 MHz: 40 KHz. Only at 7 MHz the Chameleon will have 15 KHz. So, imho your loop performs about equally. For comparison, this is the bandwidth table of your Chameleon: BAND 40 30 20 17 15 12 10 2:1 SWR BANDWIDTH (KHZ) 15 25 40 60 80 150 180

[@loughkb]

I actually measured the bandwidth of the chameleon loop with my VNA and it was narrower than that.

[@jacobboth1438]

​@@loughkbThe table data comes from the Chameleon operator's manual. So it's nice that apparently your Chameleon performs even better. Curious to see if you'll manage to equal that. Or come close. But if somebody could..73 Jaap PE1LLA

[@protektwar]

what type of cable did you use for the main loop? Aricell 7 will do the job?

[@loughkb]

As I said in the video, I don't know. I just had it on hand and there's no label on the side. A good stiff coax so it will hold its shape is what you want.

[@protektwar]

@@loughkb my bad, I missed it twice :/ Looks like the one I have keeps the shape. Do you have a link for the capacitor and connectors holder?

[@kd5inm]

Great video Kevin! De KD5INM

[@thomasmaughan4798]

It is unclear from the video and description how exactly the capacitor is wired. High RF current is flowing back and forth in the loop and consequently you want to avoid using the *wiper* contact in the capacitor. One way to achieve that is to connect one end of the loop to one stator, the other end of the loop to the other stator, and the rotor is presumably common to both stators AND the rotor is usually grounded. But in this case, the ground floats, it isn't used, and so the path is stator > rotor-rotor > stator. This doubles the voltage rating of the capacitor but of course also cuts its capacitance in half. More importantly, no high resistance wiping contact is in the path so you get optimum loop current. Now with a dual ganged capacitor you can use a capacitance match, like the MFJ portable loop tuners. Your main feed shield is connected to the frame of the capacitor and thus is common to the center of the ganged capacitor. One side of the loop, at the stator, is fed through a small variable capacitor to the center of the coax. With this approach you don't use a feed loop. You can also easily match the impedance for lowest SWR at any band and frequency. Other matching techniques exist but I like the MFJ approach as the loop itself can be made of anything conductive, 5/8ths copper tubing works great and is fed at the loop tuner, not up in the air. No need to squish the shape of the feed loop trying to get the perfect match. Just tune the little series capacitor. It interacts with main tuning a bit; so tune the loop capacitor, then the match, then re-tune the loop as needed.

[@loughkb]

I talked about the capacitor wiring in the design video. I wired to the static plates one side of the loop to each set of static plates The rotating plates are acting like two capacitors in series. This avoids a lot of the hand capacitance effect when tuning.

[@thomasmaughan4798]

@@loughkb Perfect!

[@jacobboth1438]

CHAMELEON ANTENNA CHA P-LOOP 2.0 SWR: Typically 1.5:1 or less at resonance, less than 2:1 for 15 KHz bandwidth at 7 MHz 73 PE1LLA

[@loughkb]

Yes, I have one and I have done multiple videos on it.

[@jacobboth1438]

​​​@@loughkbYou have concerns about the bandwidth. These are normal for your P-loop: BAND 40 30 20 17 15 12 10 2:1 SWR BANDWIDTH (KHZ) 15 25 40 60 80 150 180 Guess your new loop just works fine, having the same bandwidth as your Chameleon !!

[@loughkb]

No it's not the same at all. I got over 40 kilohertz bandwidth on my loop, where the chameleon was 15 or less. So there's room for improvement on my loop.

[@jacobboth1438]

​​​@@loughkblook at the above bandwidth table for the Chameleon again. The Chameleon indeed has a bandwidth of 15 KHz, but at 7 MHz. At 14 MHz the Chameleon bandwidth is 40 KHz. Same as your new loop !!. The higher the tuning frequency the higher bandwidth frequency. More cycles between 3dB points.

[@loughkb]

I actually measured the chameleon loop after I improved it by shorting the coax connectors The bandwidth came down much narrower. I did a video on it quite a while ago.

[@eduardopower5254]

Are you back amigo?

[@loughkb]

Have a look at the last four videos. Yep, only about 45%, but better.

[@davidhigginbotham5198]

I loved your comment to haters... It really is what certain people should do... Watch something else

[@akiddoo8113]

Glad to see you are back. I followed you in the past and enjoy your 'tinker' approach to radio like no other I have found. Now as to the medical sympathy - it greatly distracts from your content. I had it also but I moved on. I'm fascinated with loops and don't understand why they are not more popular after doing my own experimenting. Just remember efficiency governs usable band range. You lose 50% going up or down one band from primary. The design charts demonstrate that.

[@loughkb]

I understand your criticism, but in your case I think the operative word is had. I'm only about 45% of myself at this point. I will be absolutely thrilled when I can say had. This video took me over a week to film, I only get about an hour to an hour and a half in the morning and then I spend the rest of the day pretty much laying down completely wiped out. Two of the last four nights were completely sleepless with the insomnia flaring. I try not to talk about it too much, but it is a current issue and growing in number 12 to 14% per month. I've been trying to work on a new video now for over a week I only have about half the footage shot, I've been feeling so terrible that I just haven't had the energy to do much. So, I'm glad you can say had, and move on. And hopefully some month in the future I will be able to say the same.

[@akiddoo8113]

@@loughkbI did not say 'had' in the sense of over. I have emphysema , osteoporosis, and a liver transplant 8 years ago but I don't whine about it.

[@loughkb]

Neither do I I will occasionally talk about it though. Just to make people aware. It's a new disease, medical science is just beginning to learn about it. There is no treatment, there is no cure, and literally everybody is at risk. Every time you get COVID, you have a 10% chance of it destroying your life for a year or more. So, I will talk about it. People need to be aware.

[@digiital]

Any links to Aliexpress?

[@loughkb]

I didn't save any. Just go there and search for large variable capacitor. Also try ebay, you might get lucky.

[@digiital]

@@loughkb Thanks, I know I would have been keeping those all radios for their caps :)

[@KB1UIF]

Hi, I would not drill holes on a nice desktop like you did. One slip, and you've ruined the surface, pilot holes or not. Same for soldering over the desktop without any form of heat protection. Maybe you don't care about the surface, but it's not a good example of safety to others. Other than that, good information and video. Thanks.

[@tomtwist1081]

Why bother with the center connector of the loop coax? It will never see any RF current. The skin effect will take care of this.

[@loughkb]

The loop conductor will not see RF. The near field is mostly magnetic H field. It becomes RF some distance from the loop. By adding the center conductor, I reduce the DC resistance of the outer loop which increases its efficiency.

[@tomtwist1081]

@@loughkb I edit my comment to "RF current". The lower DC resistance will NOT affect the efficiency, as there is no RF current inside the coax.

[@loughkb]

All of my past experiments showed marked improvement when I added the center conductor. And yes, lower DC resistance on the outer loop does affect the efficiency. This is well known and documented. But you're absolutely free to build your loops however you like...

[@tomtwist1081]

@@loughkb This is rubbish. Ask anyone who knows his theory. The point that you strive to get a low DC resistance in the loop, is just that it is easier to measure than this low impedance. If there were no skin effect, you would be right, but the RF current only flows in the outer surface of the loop conductor. Skin depth for copper at 10 MHz is 20.4 μm. That is the closest the RF current will come towards the center conductor. If you have made measurements that prove otherwise, they are wrong. This is BTW easy to prove by measuring the bandwidth of the loop.

[@loughkb]

@tomtwist1081 Well you are right about the last bit, measuring the bandwidth. It would be narrower if there were an improvement in efficiency. So there's a test you can do to see if your theory is sound.

[@craigpalmer9196]

pin vise

[@loughkb]

Ah! That's what they're called... I don't even know where I got it. I'll add that reference to the video description along with an Amazon link. Thanks.

[@craigpalmer9196]

micromark

[@AdamosDad]

✋73's🎙KD9OAM🎧

[@Charles-g5d7k]

Hell-o “K”! “C”!

[@loughkb]

Hi Charlie. When are you going to start another game of Chess? It's tradition that it's up to the loser to decide to start the next one. I think...

[@Charles-g5d7k]

@@loughkb -Loser is my new name. So I’ll get to it. ⚔️🇺🇸⚔️

[@JAYDELROSARIQ]

JYQURÑ PULLED PNEGATIVE PUSHED JLQUYÑ POSITIVE