Excellent Peter...and I love the irrigation T-Piece for a cap tuning knob 🙃😂, very innovative !!!!! I have the commercial versions - MFJ-936B 150 Watts and MFJ-9232 QRP version. 73, 5Z4/ZS5J (Kenya)
Hi Peter. Yes!, it simplify a Lot making loops. Take a look my portable coax loop, i use this method. The only problem i look, is the max radiation goes near to capacitors. 73 CX1GU
Very interesting video, thanks. Can you please provide additional details on the antenna itself? How long was the cable? How high was the pole you seem to be using for the antenna? What was the approximate shape and dimensions of the loop? Did it matter for your matching unit?
Thanks for video Peter. I think mag loops are amazing - little antennas that work surprisingly well. I wonder if you have tried using regular wire rather than co-ax? Wondering if this would have a significant effect on performance?
The diameter of the wire used in the loop is extremely important. Going from 1/4 inch to 1/2 inch approximately doubles its efficiency and effective transmit power. I'm not sure that it makes that much difference on receive but seems reasonable to assume it does. There's an online calculator for mag loop antennas and you can put in various parameters and it will tell you the efficiency but using ordinary wire your efficiency is going to be only 1 or 2 percent. 1/2 inch copper tubing gives about 52 percent.
This is good, but it's not a magnetic loop antenna. It's a short transmitting loop. Perfectly decent antenna, but different category and behaviour. Your box of tricks looks great and is exactly the sort of thing we should be building rather than buying. 🙂
It is a magnetic loop antenna. Exact same schematic as the MFJ 536B. Effectively it is a gamma match which in turn is an auto-transformer. Just as a transformer is still magnetically coupled when tapping the coil so is a mag loop and at low frequencies it is a lot easier to implement a gamma match than to try to have some sort of huge inductive small loop 20 feet in the air to couple to the loop. I also find the gamma match a LOT easier to achieve 1:1 SWR.
I like this idea a lot more than the Magnetic Loop coupling method I was using. I'm going to try this instead to see how well it works for me.
Excellent Peter...and I love the irrigation T-Piece for a cap tuning knob 🙃😂, very innovative !!!!! I have the commercial versions - MFJ-936B 150 Watts and MFJ-9232 QRP version. 73, 5Z4/ZS5J (Kenya)
Congrats Peter, an other great antenna :)
I like the beaten 817, it still works perfect. These are indeed workhorses.
Hi Peter. Yes!, it simplify a Lot making loops. Take a look my portable coax loop, i use this method. The only problem i look, is the max radiation goes near to capacitors. 73 CX1GU
Very interesting video, thanks. Can you please provide additional details on the antenna itself? How long was the cable? How high was the pole you seem to be using for the antenna? What was the approximate shape and dimensions of the loop? Did it matter for your matching unit?
15m long. Rest is in the video. Nothing is critical.
@@vk3ye thanks, I'll watch it again, I must have missed it.
At about 3:30 he says 95 foot to a guy he is talking too.
Thanks for video Peter. I think mag loops are amazing - little antennas that work surprisingly well. I wonder if you have tried using regular wire rather than co-ax? Wondering if this would have a significant effect on performance?
The diameter of the wire used in the loop is extremely important. Going from 1/4 inch to 1/2 inch approximately doubles its efficiency and effective transmit power. I'm not sure that it makes that much difference on receive but seems reasonable to assume it does. There's an online calculator for mag loop antennas and you can put in various parameters and it will tell you the efficiency but using ordinary wire your efficiency is going to be only 1 or 2 percent. 1/2 inch copper tubing gives about 52 percent.
This is good, but it's not a magnetic loop antenna. It's a short transmitting loop. Perfectly decent antenna, but different category and behaviour. Your box of tricks looks great and is exactly the sort of thing we should be building rather than buying. 🙂
It is a magnetic loop antenna. Exact same schematic as the MFJ 536B. Effectively it is a gamma match which in turn is an auto-transformer. Just as a transformer is still magnetically coupled when tapping the coil so is a mag loop and at low frequencies it is a lot easier to implement a gamma match than to try to have some sort of huge inductive small loop 20 feet in the air to couple to the loop. I also find the gamma match a LOT easier to achieve 1:1 SWR.
I don’t see the two loops that constitute a mag loop antenna. Did I miss something?
Mag loops often have two loops or a gamma match arrangement. This loop is different again with the loop fed at the capacitor end.
I still don’t understand. You showed a picture of a wire going up to a pole. But I didn’t see a circular loop.
@@hughbassoon There is no circular loop. See the diagram at 1:07.
Ok..I see the circular structure in the diagram. I just didn’t see your circular structure in subsequent slides I’ll look again.
I’ll take your word for it.
Great! Many possibilities! ;)
What's the furthest station you worked?
Good work Pete, looks awesome! de ZL1 Big hairy dog
Thanks for not actually explain much. Not a good video at all.
why not show us the bw?