I've always wanted to build a 2 element 40 meter Yaggi. I have the space for it, but often I am just too busy elsewhere. I used to build up to 4 element vertical 10 meter Yaggis like a rope ladder and I used a 12.5 calculated impedance at the feedpoint to make them very short in boom length. I then used a folded dipole as the driven element to alter impedance back to about 50 ohms. They worked really well, unfortunately the technique does not scale up to 40 meter size easily. You guys, have likely already had the fun of building one but I need a piece of the fun pie too & antennas certainly are fun to make effective....
@@migalito1955Alternatively, do what Callum has done, create a vertical two element beam using quarter wave ground plane verticals, either phased or passive.
But this is why i keep two antennas. I have my 12.4m Signature, That i absolutely love. And a 135' Doublet fed with 600ohm. If one doesn't get the contact, the other will.
Hi Callum, trying to access your website via iPad or iPhone and I get a notification that it couldn’t establish a secure connection to the server. Maybe an Apple Safari thing dont know. Regards Mike
I love when you draw things! Have you ever thought of raffling off those sketch books for charity? They are works of art technically.😊 Thanks again for all that you do!
R..iii..ght errr I’ll take your word for this Cal 😵💫 I’m really p.poor at anything maths… I’ve just got plus minus times divide understood, coz I’m thick I suppose… 🧐 still passed my G0 licence though way back when I was just an harmonic 😆 🤣 💙
1:09 Fill the balloon with water, then the analogy works. 🙂 Water in incompressible, air is not. Anyway, that nitpicking. Nice video, good explanation.
Everything's relative. Especially in Alabama. New measurement, dBb. Relative length to a banana. As for poking fingers in balloons and bulges changing shape, my belt does that to my stomach.
Helpful, now i'll have to watch the Db vid AGAIN. Maths defeats me especially when - x - = + and then there's 3.142........where does it end.........Wigglies and Bananas. Good Grief !
I just thought a downside of using dBb (relative to a banana). Are we talking about distance/length or are we talking about calories? How many dBb does a pie have relative to a banana?
I dislike dBi because it changes with height and the quality of the ground, using it for comparison takes the thoroughness of a man like Cebik, I would say no one else ever explains their comparison in enough detail for it to be even worth reading.
Dbi needs to be canned. Dbd and dbd over average ground more reasonable. These companies will never understand that true gain sells. Innov meh they’re getting better. Not quite there yet.
dBi does not "need to be canned". Reference to a theoretical isotropic radiator is a perfectly scientific and valid comparison. What needs to happen is that amateur radio ops / hams need to partake in self learning and critical thinking, and gain a decent understanding of the comparison to various reference antennas.
@@JayN4GO"dBd over average ground" isn't realistic. I understand your point but as soon as "average" is brought in to the discussion it infers statistical mean, standard deviation and variance...
You so often make videos on radio theory topics I've been meaning to get my head around, you're a credit to the community, 73.
Hey thanks!
I've always wanted to build a 2 element 40 meter Yaggi. I have the space for it, but often I am just too busy elsewhere. I used to build up to 4 element vertical 10 meter Yaggis like a rope ladder and I used a 12.5 calculated impedance at the feedpoint to make them very short in boom length. I then used a folded dipole as the driven element to alter impedance back to about 50 ohms. They worked really well, unfortunately the technique does not scale up to 40 meter size easily.
You guys, have likely already had the fun of building one but I need a piece of the fun pie too & antennas certainly are fun to make effective....
Well.. It would scale - you just need a huge tower - and some extra money! PS - Great technique for the impedance transformation!
What about building a 40m Moxon?
@@paulsengupta971 You know, that actually is a good idea... i like it.
@@DXCommanderHQ Spot on with my wallet is to thin for the towers needed.
@@migalito1955Alternatively, do what Callum has done, create a vertical two element beam using quarter wave ground plane verticals, either phased or passive.
But this is why i keep two antennas. I have my 12.4m Signature, That i absolutely love. And a 135' Doublet fed with 600ohm. If one doesn't get the contact, the other will.
Perfect!
"poke a balloon in the middle" 🤯 such a simple explanation to understand 😂 thanks!
You bet!
Fantastic explanation!
Great :)
Hi Callum, trying to access your website via iPad or iPhone and I get a notification that it couldn’t establish a secure connection to the server. Maybe an Apple Safari thing dont know. Regards Mike
Hmmm. We're through CloudFlare.. It might be a glitch.
Love this, very good videos explaining dB!
Much appreciated!
kept staring at the dot - We love Lord Callum - We love Lord Callum - We love Lord Callum !!!🤣🤣
We love Lord Callum. @_@
HAHA.. Crazy! You've been watching too many of my videos!!
I love when you draw things! Have you ever thought of raffling off those sketch books for charity?
They are works of art technically.😊 Thanks again for all that you do!
Good point.. I keep meaning to do something with them...!
thanks Call 73!
Any time!
Cal. Thanks for showing the dBb ruler, or dB relative to bananas measurerer. :) Ha!
HAHA
R..iii..ght errr I’ll take your word for this Cal 😵💫 I’m really p.poor at anything maths… I’ve just got plus minus times divide understood, coz I’m thick I suppose… 🧐 still passed my G0 licence though way back when I was just an harmonic 😆 🤣 💙
You are funny!!
So, more banana's are better?🍌😂
Thanks Callum. ;)
Yes Sir!!
1:09 Fill the balloon with water, then the analogy works. 🙂 Water in incompressible, air is not. Anyway, that nitpicking. Nice video, good explanation.
Yes OK.. I would like you to see your hand compress air :)
@@DXCommanderHQ If you're as old as me, you've probably done that with a bicycle pump. 🙂
Is it legal in the UK to stick your fingers in a balloon? Goodness, I must be missing out. Great Video as usual. KB3NG
Yes, new legislation was passed last year!
Everything's relative. Especially in Alabama. New measurement, dBb. Relative length to a banana. As for poking fingers in balloons and bulges changing shape, my belt does that to my stomach.
HAHA!!
The Sun is a pretty good isotropic radiator.
Oh yes! It's just a million times bigger than this planet..!
Helpful, now i'll have to watch the Db vid AGAIN. Maths defeats me especially when - x - = + and then there's 3.142........where does it end.........Wigglies and Bananas. Good Grief !
Ah.. 3.142. At least you know off by heart!
I just thought a downside of using dBb (relative to a banana). Are we talking about distance/length or are we talking about calories? How many dBb does a pie have relative to a banana?
if UK try SLIMMING WORLD RADIO , Sir ;-)@@paulsengupta971
I dislike dBi because it changes with height and the quality of the ground, using it for comparison takes the thoroughness of a man like Cebik, I would say no one else ever explains their comparison in enough detail for it to be even worth reading.
Well dBi NEVER changes, that's the point.. Everything else does though! :)
Antenna fiends change. Entropy. Something to do with putting up antennas while drinking cups of tea.
@@DXCommanderHQ my bad, I am a terrible editor, I meant dbd
Heii Call🫡 I'm steal here and watchig you👻 My friend
Hello old friend!!!
Dbi needs to be canned. Dbd and dbd over average ground more reasonable. These companies will never understand that true gain sells. Innov meh they’re getting better. Not quite there yet.
dBi does not "need to be canned". Reference to a theoretical isotropic radiator is a perfectly scientific and valid comparison. What needs to happen is that amateur radio ops / hams need to partake in self learning and critical thinking, and gain a decent understanding of the comparison to various reference antennas.
@@petemillis4666 there shouldn’t be 3 imaginary made up reference points to base scientific theories. Make the shit realistic
@@JayN4GO"dBd over average ground" isn't realistic. I understand your point but as soon as "average" is brought in to the discussion it infers statistical mean, standard deviation and variance...
Sir your video being good - down side to this: you never do sketches to help Beginners to understand to what you are trying say and do or teach
First. Good afternoon cal
Good bananas day!
Then there is dBDXC 😂
Oh yes!!
Real explanation very cool 😎KQ4OHB
Thanks 👍