Ran across your call in my 20 m WSPR log report this morning. Looked you up on QRZ and then found you here. Interesting life you've had! Thanks for sharing. 73, Elwood, WB0OEW
After 20 years on the air I've finally got round to exploring 160m with a loop, and am having a great time working the lower frequencies, but your efforts are way more adventurous than mine. Good luck with this project, I wish you every success, and look forward to listening to your transmissions although I doubt your signal ever reaches the UK. Perhaps when I win the lottery and can afford the real estate I'll look at the lower frequencies too, but until then top band is probably my limit.
"Thank you, I will just stick with my Baofeng HT. Your stuff just seems wa-a-a-y too complex!" ~new "Baofeng Tech" Seriously, great video! Working 160m now seems like working 1.2 gig!
2:37 Let's see...transformer turns ratio is 2 to 13, secondary current 50A, so primary current would be 50 x 2/13 = 7.7A. At 50 ohms that's 50 x 7.7 = 385 V, which means 385 x 7.7 = 2965 W, or just under 3 kW, a good amount of oomph coming from your transmitter! (Well, I've assumed volts and amps are in phase, not sure if they really are...)
Thanks for the maths! Yes a lot of Ommph - certainly less than 7.7A on the primary (I have an old War dept 10A thermocouple of dubious status and it reads around 4.7A (RMS I guess) - It would not surprise me if secondary RF current is less than 50A - If we say we have around 1400 Watts carrier, ie Im not pulsing we can work back from there - my losses are higher here than when we ran the same tx but smaller lower AC loss loss loop (lot os parallel TFFN6 and 4 cables but the EIRP appears to be very similar and even with the ommpf difficult to attain 1W EIRP on the main lobe(s)
What an amazing project. Thanks for sharing. I am no where near being able to approach that band - my current “goal band” is 160 m ! I was dismayed though that for 1KW in you are reporting 1-2 ERP. Where’s it all going ? Shouldn’t your tuning network be hot ? 73. KD2ODE
Hi John - Ive just put my first overnight transmission from the loop and tuning really hadnt changed at all over the period. Well, there are quite a few losses involved - ground loss is big of course - conductor losses at 137kHz of the wire itself - in theory I Could have gone bigger diameter but less physically strong, but here its a matter of physical survival and a toss up of weight and RF losses. Other losses are dielectric losses in the tuning components, losses in the ferrite itself - Physical size of this loop at 137 kHz isn't ideal and again a large part of the loss of efficiency - but there are tree survival and weight bearing limits on open spans. Theres a great loop calculator that sort of works at www.66pacific.com and you can play with size, wire diameters etc. gives you voltages and resonating C too. Cheers from Alaska
hellozerohellozero thanks much. I will enjoy doing some “what if’s” with the online calculators. Close to our shore QTH in a Tuckerton NJ there is an old -what appears to be - a VLF transmitting antenna which I have assumed was meant for submarine coms. It’s arranged as a spiral - ie an ever-widening circle of perhaps 12 rings, suspended from telephone pole high posts. I assume that the navy could care less about lost power, as long as the ERP is where they need it to be, but I’ve wondered if a widely gapped spiral loop at some 50 feet off the ground might have benefits. Thanks again and 73s JOHN KD2ODE
Yes the efficiency is that bad, or good, dependent on your viewpoint - but getting to 1W EIRP is the license goalpost in any case, but thats sufficient to be heard in Eu or Zl on a good iono day with the wind behind….
So the range is dependant on season - typically in Winter mutual darkness months it can reach Japan, Australia and New Zealand, with nice Sea water paths and given its directional not so Good over the Pole to Europe. Per the video Its "Q" is very high and can only transmit data beit digital modes such as WSJTX WSPR or CW - nothing more than a say 50Hz bandwidth without issues with the antenna acting like a tight bandpass filter - so no lo-fi AM or even narrow SSB without issues - C-QUAM seems to be in the same category.
Ran across your call in my 20 m WSPR log report this morning. Looked you up on QRZ and then found you here. Interesting life you've had! Thanks for sharing. 73, Elwood, WB0OEW
After 20 years on the air I've finally got round to exploring 160m with a loop, and am having a great time working the lower frequencies, but your efforts are way more adventurous than mine. Good luck with this project, I wish you every success, and look forward to listening to your transmissions although I doubt your signal ever reaches the UK. Perhaps when I win the lottery and can afford the real estate I'll look at the lower frequencies too, but until then top band is probably my limit.
Very impressive! I love the physics involved in this kind of experimentation.
Bravoo🗼👍😊
"Thank you, I will just stick with my Baofeng HT. Your stuff just seems wa-a-a-y too complex!"
~new "Baofeng Tech"
Seriously, great video! Working 160m now seems like working 1.2 gig!
Very impressive project. I only wish I had your understanding of the antenna electronic aspects.
What a beautiful nature...
thanks Elwood
2:37 Let's see...transformer turns ratio is 2 to 13, secondary current 50A, so primary current would be 50 x 2/13 = 7.7A. At 50 ohms that's 50 x 7.7 = 385 V, which means 385 x 7.7 = 2965 W, or just under 3 kW, a good amount of oomph coming from your transmitter! (Well, I've assumed volts and amps are in phase, not sure if they really are...)
Thanks for the maths! Yes a lot of Ommph - certainly less than 7.7A on the primary (I have an old War dept 10A thermocouple of dubious status and it reads around 4.7A (RMS I guess) - It would not surprise me if secondary RF current is less than 50A - If we say we have around 1400 Watts carrier, ie Im not pulsing we can work back from there - my losses are higher here than when we ran the same tx but smaller lower AC loss loss loop (lot os parallel TFFN6 and 4 cables but the EIRP appears to be very similar and even with the ommpf difficult to attain 1W EIRP on the main lobe(s)
2200m, 1W... Are you doing anything with The Longest Band? There can't be much that gets in the way of those waves once they actually radiated
you can do a lot
What an amazing project. Thanks for sharing. I am no where near being able to approach that band - my current “goal band” is 160 m ! I was dismayed though that for 1KW in you are reporting 1-2 ERP. Where’s it all going ? Shouldn’t your tuning network be hot ? 73. KD2ODE
Hi John - Ive just put my first overnight transmission from the loop and tuning really hadnt changed at all over the period. Well, there are quite a few losses involved - ground loss is big of course - conductor losses at 137kHz of the wire itself - in theory I Could have gone bigger diameter but less physically strong, but here its a matter of physical survival and a toss up of weight and RF losses. Other losses are dielectric losses in the tuning components, losses in the ferrite itself - Physical size of this loop at 137 kHz isn't ideal and again a large part of the loss of efficiency - but there are tree survival and weight bearing limits on open spans. Theres a great loop calculator that sort of works at www.66pacific.com and you can play with size, wire diameters etc. gives you voltages and resonating C too. Cheers from Alaska
hellozerohellozero thanks much. I will enjoy doing some “what if’s” with the online calculators. Close to our shore QTH in a Tuckerton NJ there is an old -what appears to be - a VLF transmitting antenna which I have assumed was meant for submarine coms. It’s arranged as a spiral - ie an ever-widening circle of perhaps 12 rings, suspended from telephone pole high posts. I assume that the navy could care less about lost power, as long as the ERP is where they need it to be, but I’ve wondered if a widely gapped spiral loop at some 50 feet off the ground might have benefits. Thanks again and 73s JOHN KD2ODE
how did you string up wire
Catapult ! If you search my you tube content there should be a short awful instructional video :-)
Wait. 1kw in and a few watts out?...
Yes the efficiency is that bad, or good, dependent on your viewpoint - but getting to 1W EIRP is the license goalpost in any case, but thats sufficient to be heard in Eu or Zl on a good iono day with the wind behind….
Range? Can you transmit in C-QUAM AM mode?
So the range is dependant on season - typically in Winter mutual darkness months it can reach Japan, Australia and New Zealand, with nice Sea water paths and given its directional not so Good over the Pole to Europe. Per the video Its "Q" is very high and can only transmit data beit digital modes such as WSJTX WSPR or CW - nothing more than a say 50Hz bandwidth without issues with the antenna acting like a tight bandpass filter - so no lo-fi AM or even narrow SSB without issues - C-QUAM seems to be in the same category.
@@hellozerohellozero any great stereo tool presets/settings for this?
You need to work on your craftsmanship. :(