I think the size of the driving element is being determined by the circumference of the main loop, so it looks too big, but the main loops a multiple turns.
Just curious, what's your height of the bottom of your Loop? I have the Baby-loop made by Ciro Mazzoni. Still trying to maximize my satisfaction with it. Thanks.
I have built a number of these loops. The basic loop construction is simple. Some of these loops have been compromises in terms of how much they qualify as "homebrew." MFJ sells a quick and easy solution in the form of their MFJ-933C loop tuner and its variants. It is easy to use one of these and cobble together a mag loop for portable use. Because it is manually tuned, it is less well suited for permanent installation. The first challenge in building loops is in constructing a remote tuner. A geared reversible DC motor with a PWM speed controller. These small transmitting loops have exceptionally high Q and very limited usable bandwidth at resonance. They need to be retuned to compensate for changes in temperature and humidity as well as other factors. A NanoVNA with a combination of VSWR curve and a Smith chart works well. The second challenge is to buy or build a variable capacitor that can handle high voltage. The high voltage requirement will allow the loop to function above QRP levels.
Iam not sure what you did to your lapel microphone Dave but, it isn't working like it usually does, sounds like it isn't working at all, sounds like your in a huge room. 👍
Copper pipe might be difficult to bend without a proper pipe bending jig. I have made a loop from ⅜" coax which is 22" diameter for the higher frequencies. I have got into Europe with QRP c.w. with the loop indoors. I bought a 3V motor with gearbox to drive the capacitor which for QRP doesn't need wide spacing. All sources say the smaller coupling loop should be one fifth diameter of the main loop, but multiturn loops perhaps a larger loop needed. Experiment! I'm going to try another made from this spare length of 19' coax for lower frequencies. G4GHB
@@bassmanjr100 That does make sense, and coax could soon corrode on the braid with condensation in winter. I just had this spare coax to try indoors. G4GHB.
I was talking about Magnetic loop antenna with Japanese Ham, surprisingly. many of them did not even know about it. I never used one, but I have heard they do work similar to full size dipole. many of Japanese Ham , they believe such small things work at all. and not willing to pay for a lot of money to try them out. AG6JU
I have seen the one sold at Rocket Ham Radio in Akihabara. It appears well made but uses a trombone capacitor which makes tuning bands a time consuming process. IIRC you can buy it in one-two-three-and four loop variants and you can get optional modules that I think are just fixed capacitors that you bolt onto it to access the lower bands. There is also a remote controller but I don't believe it is automatic. I don't know how good or bad they are but the man in the store recommended a loaded V-dipole instead for DX-ing purposes. It, too, requires frequent tuning, but the ATU in most radios can handle it. KD2ORG
@@sincerelyyours7538 I see, many Japanese Ham use V shape loaded dipole. antenna like windom , G5RV, end Fed, Inverted L, anything uses ladder line are not popular there at all. in US , vertical are popular in city, but not many use Vertical in Japan either. when I was in Japan, I only operated VHF from home, HF from high school radio club. AG6JU ex JG6IUB
@@Porco_Utah I've noticed that too. I had to buy 50 ft of ladder line from the US because no one sold it in Japan. A ham near my house has three antennas - a 2M / 70cm vertical, a Diamond 15 / 40M inverted-V loaded dipole (I have the same antenna), and a multi-band V loaded dipole mounted on a rotator. He says none of them work very well, but he has reached the US on occasion. I plan to make a 40-10M Doublet antenna after I get my JARL Permission to Operate license. Finding enough space for any antenna in a typical Japanese garden is very difficult, especially since I've never done this before and have no Elmer to guide me. KD2ORG
@@sincerelyyours7538 In Japan, specially in city , and rental apartment and such. amateur radio can be tough . when I was renting apartment in Yokohama, I did not operate Amateur radio at all even VHF. HF was out of question then. doublet antenna is good antenna. if I had more yard space here in Orange County, doublet is the antenna I would use. perhaps, you can make your own ladder line. there are many article making ladder line. construction does not have to be accurate. and cheap to make. some Japanese ham use disposable wooden or bamboo chop sticks as insulator / spacer for ladder line. but UV proof plastic are better choice. in Japan, Ham radio licensing can be quite difficult and complicated compare to US. because they treat Amateur radio as almost same as commercial station license. and pretty much need to use radio certified by Japanese government for simplified licensing procedure. I understand non fixed station are limited to 50 watts, more than that power level only licensed as fixed station. AG6JU ex JG6IUB
That indoor triple-loop antenna looks formidable! Thanks for the interesting video.
Thanks, Dave. 73, AC3HT
I think the size of the driving element is being determined by the circumference of the main loop, so it looks too big, but the main loops a multiple turns.
I have two Ciro Mazzoni antennas from Italy… best antennas i have ever used
The small loop is about 4ft and the large is over 6ft diameter
Just curious, what's your height of the bottom of your Loop? I have the Baby-loop made by Ciro Mazzoni. Still trying to maximize my satisfaction with it. Thanks.
I checked Amazon for the book but it is unavailable.
For the sake of RF proximity safety, I wouldn't want to run any sort of power through that indoor loop.
I agree the results could be, shocking.....
Those birds would quickly become... fried 😂
Thank you.
I have been interested in hf loop antennas for some time, but never tried one. N0QFT
I have built a number of these loops. The basic loop construction is simple. Some of these loops have been compromises in terms of how much they qualify as "homebrew." MFJ sells a quick and easy solution in the form of their MFJ-933C loop tuner and its variants. It is easy to use one of these and cobble together a mag loop for portable use. Because it is manually tuned, it is less well suited for permanent installation.
The first challenge in building loops is in constructing a remote tuner. A geared reversible DC motor with a PWM speed controller. These small transmitting loops have exceptionally high Q and very limited usable bandwidth at resonance. They need to be retuned to compensate for changes in temperature and humidity as well as other factors. A NanoVNA with a combination of VSWR curve and a Smith chart works well.
The second challenge is to buy or build a variable capacitor that can handle high voltage. The high voltage requirement will allow the loop to function above QRP levels.
Iam not sure what you did to your lapel microphone Dave but, it isn't working like it usually does, sounds like it isn't working at all, sounds like your in a huge room. 👍
Copper pipe might be difficult to bend without a proper pipe bending jig.
I have made a loop from ⅜" coax which is 22" diameter for the higher frequencies. I have got into Europe with QRP c.w. with the loop indoors. I bought a 3V motor with gearbox to drive the capacitor which for QRP doesn't need wide spacing.
All sources say the smaller coupling loop should be one fifth diameter of the main loop, but multiturn loops perhaps a larger loop needed. Experiment!
I'm going to try another made from this spare length of 19' coax for lower frequencies.
G4GHB
The data I saw showed that coax does not make for a great outside loop. The more surface area you can get into that outside loop, the better.
@@bassmanjr100 That does make sense, and coax could soon corrode on the braid with condensation in winter. I just had this spare coax to try indoors.
G4GHB.
I was talking about Magnetic loop antenna with Japanese Ham, surprisingly. many of them did not even know about it. I never used one, but I have heard they do work similar to full size dipole. many of Japanese Ham , they believe such small things work at all. and not willing to pay for a lot of money to try them out. AG6JU
I have seen the one sold at Rocket Ham Radio in Akihabara. It appears well made but uses a trombone capacitor which makes tuning bands a time consuming process. IIRC you can buy it in one-two-three-and four loop variants and you can get optional modules that I think are just fixed capacitors that you bolt onto it to access the lower bands. There is also a remote controller but I don't believe it is automatic. I don't know how good or bad they are but the man in the store recommended a loaded V-dipole instead for DX-ing purposes. It, too, requires frequent tuning, but the ATU in most radios can handle it. KD2ORG
@@sincerelyyours7538 I see, many Japanese Ham use V shape loaded dipole. antenna like windom , G5RV, end Fed, Inverted L, anything uses ladder line are not popular there at all. in US , vertical are popular in city, but not many use Vertical in Japan either. when I was in Japan, I only operated VHF from home, HF from high school radio club. AG6JU ex JG6IUB
@@Porco_Utah I've noticed that too. I had to buy 50 ft of ladder line from the US because no one sold it in Japan. A ham near my house has three antennas - a 2M / 70cm vertical, a Diamond 15 / 40M inverted-V loaded dipole (I have the same antenna), and a multi-band V loaded dipole mounted on a rotator. He says none of them work very well, but he has reached the US on occasion. I plan to make a 40-10M Doublet antenna after I get my JARL Permission to Operate license. Finding enough space for any antenna in a typical Japanese garden is very difficult, especially since I've never done this before and have no Elmer to guide me. KD2ORG
@@sincerelyyours7538 In Japan, specially in city , and rental apartment and such. amateur radio can be tough .
when I was renting apartment in Yokohama, I did not operate Amateur radio at all even VHF. HF was out of question then.
doublet antenna is good antenna. if I had more yard space here in Orange County, doublet is the antenna I would use. perhaps, you can make your own ladder line. there are many article making ladder line. construction does not have to be accurate. and cheap to make. some Japanese ham use disposable wooden or bamboo chop sticks as insulator / spacer for ladder line. but UV proof plastic are better choice.
in Japan, Ham radio licensing can be quite difficult and complicated compare to US.
because they treat Amateur radio as almost same as commercial station license.
and pretty much need to use radio certified by Japanese government for simplified licensing procedure.
I understand non fixed station are limited to 50 watts, more than that power level only licensed as fixed station.
AG6JU ex JG6IUB
I bet he was screen grabbing like crazy 😂🤣
THESE days, $50 is closer to the cost of BREAKFAST with your significant other
Not if your wife is a good cook. Lol
@@BillyBob-xd8qj What if your husband is the better cook?