*MAJOR LESSON HERE:* Trap dipoles are tuned from the center out. Do not attach the traps until you have pruned the 20m dipole down to it's desired resonant frequency -- and even then, don't solder the wire to the trap. (Tin it and push it through the holes.) And then add the outer part of the leg -- which you can solder because you can trim the outer ends of the antenna. Once the the antenna is resonant at the 40m frequency you want, you can solder the 20m inner part of the leg, slip the shrink tube over the trap, melt it in place, and add the PVC loops to the end. If you are careful, it will be perfectly tuned for BOTH bands.
Nice kit... If I may offer one suggestion, since you have that nice, large solder pad around the BNC, I'd add two solder joints from the bnc connector to that pad just to ensure you have a great ground there - considering the torque from the coax. Put the iron tip on the bnc flange & add solder at the pad/ flange joint - go around about 20 degrees on each side - pre-add some flux too to help transfer the heat. 73
Just started to build this antenna after purchasing it months ago. One of the guys in my radio club has put about 6 of these together. He cuts the inner legs at 15’ 6” and the outside legs get trimmed between 8’ 5” to 9’. Also noticed you had excessive wire after doing the 51 wraps… I had about the same excess and I thought I did something wrong.
At 4:34 when you make your last wrap and go back through the hole for the 1" lead, does that wrap count as a wrap or you go back through again? I would think if the in/out holes in the coil don't line up it would be obvious, but where do you start and stop counting if the holes line up?
*ADDITIONAL COMMENT:* You want to have fun? Make your own trap antenna by using toilet paper tubes for the coil forms. There is no magic; you'll just have to figure out the inductance of the coil you wound in Jim's kit by reversing the parameters (6-inch coil 3/4" in length with 51 turns equals what inductance?) Then *recalculate* the number of turns for a TP tube and wind away. Then calculate the resonant frequency for the that inductance and figure out the capacitance. That should be the total of the RECIPROCAL of the caps so Jim's kit has two 27 pF caps or about 13 pF series capacitance. To make the trap resonate at about 14 Mhz, you will need to wind a coil with about 10 uH inductance. (Close enough for government work.) Give it a try. It's not that hard!
I have an ICOM 7300 but not a separate tuner/analyzer. I'm a new HAM and am not sure on adjusting the antenna. Could I just put it together and hang it and rely on the ICOM tuner for correction?
As long as you stay below 3:1 it wil tune. But remember! A tuner does not tune the antenna, it makes the radio think the antenna is tuned. It is always better to get the antenna resonant where you want it to be so you don't get any power reflected back. If the SWR is no higher than 2:1 (about 10% loss from the output power, so effectively about 90% is send out by the antenna) you can do without a tuner. Lower is always better of course. I always check my SWR before I connect any of my antenna's with a Rigexpert analyzer. A good analyzer is a must have, of course you gotta have budget. But if you do, get one. It will protect your radio from SWR mayhem and it will help to get the best from your antenna. 73
So Rob, could you possibly let us know what the lengths of each segment wound up being after you had it tuned for the final time? Great video sir!!! 73!
Hello. I'm hoping you can help me quick because I'm in the process of putting one of these together. On the BNC there's a small metal washer with a tab on it. I do not know where exactly to solder that??does it solder with the wires or to the center conductor wire? Please help. Thank You
I thought I showed it in the video and explained how it was connected. Give it another look and if you don't see it let me know and I'll go look at mine to see what I did
After looking at the website, I’m wondering if you could combine the 20/40 kit and 17/30 kit with an LDG 1:1 balun to have a 4 band antenna on 1 pole with 1 feed line. I may have to try that!
@@SevenFortyOne ..bet you it would not. The interaction would compound and over-complicate the tune-up process greatly! You are better off building a fan dipole with separate elements for band. 40m would be approximately 33 feet for each leg, 30m would be 23.5 feet, 20 would be 16.5 feet, and 17m would be 12 feet. Adjustment then would involve only trimming each leg of the fan dipole until all came into resonance.
I am trying to homebrew same antenna for my limited space use. Can you please tell me inductance of just trap? it will help making my own coil and get it resonating with 2x 27pf. I think 2 caps are in seires correct me if I am wrong. Thanks in advance.
I am in the process of studying for my tech license can you give me any suggestion on apps to study on I got several of them but I'm finding out that things are not sinking into my head I have a problem with taking test hands on them okay you could show me and I would probably pick it up a whole lot easier can you give me any suggestions
Its been a long time since I was licensed or involved with directly getting anyone licensed. I Can tell you that several Ham Radio UA-camrs have put out that have full video series on getting licensed. Check out Ham Radio Crash Course, Ham Radio2.0, and Dave Cassler's channels on UA-cam. And if you have specific questions, feel free to drop any of us ham youtubers an email if you think we can help.
I placed an order on their website. No customer service. No order confirmation. And the money went down from the credit. And do not answer emails. Tips?
Why not mention the metal ring with the arm with the little hole? Where does it go? It lines up with a hole on the board, why not mention that? The instructions that came with it doesn't mention it either.
So Rob, could you possibly let us know what the lengths of each segment wound up being after you had it tuned for the final time? Great video sir!!! 73!
@@SevenFortyOne Awesome, thanks. I may pick one of those up to try out. I've been thinking about working some portable lately. Thanks for the video and all the info! 73!
*MAJOR LESSON HERE:* Trap dipoles are tuned from the center out. Do not attach the traps until you have pruned the 20m dipole down to it's desired resonant frequency -- and even then, don't solder the wire to the trap. (Tin it and push it through the holes.) And then add the outer part of the leg -- which you can solder because you can trim the outer ends of the antenna. Once the the antenna is resonant at the 40m frequency you want, you can solder the 20m inner part of the leg, slip the shrink tube over the trap, melt it in place, and add the PVC loops to the end.
If you are careful, it will be perfectly tuned for BOTH bands.
Nice kit...
If I may offer one suggestion, since you have that nice, large solder pad around the BNC, I'd add two solder joints from the bnc connector to that pad just to ensure you have a great ground there - considering the torque from the coax.
Put the iron tip on the bnc flange & add solder at the pad/ flange joint - go around about 20 degrees on each side - pre-add some flux too to help transfer the heat.
73
Easy to build, easy to tune, works great in an inverted V.
Enjoyed this, and others comments, just what I was looking for 73's KL7REV
Awesome -glad this helped!
Just started to build this antenna after purchasing it months ago. One of the guys in my radio club has put about 6 of these together. He cuts the inner legs at 15’ 6” and the outside legs get trimmed between 8’ 5” to 9’.
Also noticed you had excessive wire after doing the 51 wraps… I had about the same excess and I thought I did something wrong.
Watched your video and ordered the kit. Very well put together vid.
That is really cool. And you get to build it.
Nice demo and not too long a video!
At 4:34 when you make your last wrap and go back through the hole for the 1" lead, does that wrap count as a wrap or you go back through again? I would think if the in/out holes in the coil don't line up it would be obvious, but where do you start and stop counting if the holes line up?
Nice job!
*ADDITIONAL COMMENT:* You want to have fun? Make your own trap antenna by using toilet paper tubes for the coil forms. There is no magic; you'll just have to figure out the inductance of the coil you wound in Jim's kit by reversing the parameters (6-inch coil 3/4" in length with 51 turns equals what inductance?) Then *recalculate* the number of turns for a TP tube and wind away. Then calculate the resonant frequency for the that inductance and figure out the capacitance. That should be the total of the RECIPROCAL of the caps so Jim's kit has two 27 pF caps or about 13 pF series capacitance. To make the trap resonate at about 14 Mhz, you will need to wind a coil with about 10 uH inductance. (Close enough for government work.)
Give it a try. It's not that hard!
I have an ICOM 7300 but not a separate tuner/analyzer. I'm a new HAM and am not sure on adjusting the antenna. Could I just put it together and hang it and rely on the ICOM tuner for correction?
The answer is always...it depends. The internal tuner in your icom should handle it as long as it's not too far off
As long as you stay below 3:1 it wil tune. But remember! A tuner does not tune the antenna, it makes the radio think the antenna is tuned. It is always better to get the antenna resonant where you want it to be so you don't get any power reflected back. If the SWR is no higher than 2:1 (about 10% loss from the output power, so effectively about 90% is send out by the antenna) you can do without a tuner. Lower is always better of course. I always check my SWR before I connect any of my antenna's with a Rigexpert analyzer. A good analyzer is a must have, of course you gotta have budget. But if you do, get one. It will protect your radio from SWR mayhem and it will help to get the best from your antenna. 73
Great video. Thanks. 73's KG7LOI
Great video and thanks for easy instruction
At 10:40 - see? In told you!
😊
Told me what?
So Rob, could you possibly let us know what the lengths of each segment wound up being after you had it tuned for the final time? Great video sir!!! 73!
Good deal.
Hello. I'm hoping you can help me quick because I'm in the process of putting one of these together. On the BNC there's a small metal washer with a tab on it. I do not know where exactly to solder that??does it solder with the wires or to the center conductor wire? Please help. Thank You
I thought I showed it in the video and explained how it was connected. Give it another look and if you don't see it let me know and I'll go look at mine to see what I did
After looking at the website, I’m wondering if you could combine the 20/40 kit and 17/30 kit with an LDG 1:1 balun to have a 4 band antenna on 1 pole with 1 feed line. I may have to try that!
Interesting...I bet it would work fine
@@SevenFortyOne ..bet you it would not. The interaction would compound and over-complicate the tune-up process greatly! You are better off building a fan dipole with separate elements for band. 40m would be approximately 33 feet for each leg, 30m would be 23.5 feet, 20 would be 16.5 feet, and 17m would be 12 feet. Adjustment then would involve only trimming each leg of the fan dipole until all came into resonance.
I am trying to homebrew same antenna for my limited space use. Can you please tell me inductance of just trap? it will help making my own coil and get it resonating with 2x 27pf. I think 2 caps are in seires correct me if I am wrong. Thanks in advance.
Sorry, I don't know what the inductance is on the coils
Good video!! What is the value of the capacitors??
Thanks! Sorry, I don't remember
27pF 3KV capacitors
how many cm is the outer diameter of the pipe?
the thickness of the cable?
If you mean the "pipe" that forms the coils, its about 16mm
@@SevenFortyOne Yes thank you very much and how many awg is the cable?
I think it is 16awg
I am in the process of studying for my tech license can you give me any suggestion on apps to study on I got several of them but I'm finding out that things are not sinking into my head I have a problem with taking test hands on them okay you could show me and I would probably pick it up a whole lot easier can you give me any suggestions
Its been a long time since I was licensed or involved with directly getting anyone licensed. I Can tell you that several Ham Radio UA-camrs have put out that have full video series on getting licensed. Check out Ham Radio Crash Course, Ham Radio2.0, and Dave Cassler's channels on UA-cam. And if you have specific questions, feel free to drop any of us ham youtubers an email if you think we can help.
@@SevenFortyOne thank you
I placed an order on their website. No customer service. No order confirmation. And the money went down from the credit. And do not answer emails. Tips?
I used PayPal and got a confirmation from them. I think it took about a week for me to receive my items
@@SevenFortyOne You purchased, did they confirm your order? Did someone text you? Were you in touch? Very strange, everything is one-sided ...
Send them 6 emails. As if it's in the air
Why not mention the metal ring with the arm with the little hole? Where does it go? It lines up with a hole on the board, why not mention that? The instructions that came with it doesn't mention it either.
hallo brother how many size capasitor ?
27pF capacitors
that home dopie 14ga thhn is now $70
You can't make this yourself because????
You can if you want to but this kit wad probably cheaper than it would be to buy all the pieces
@@SevenFortyOne fair call
It was obvious that it's not cut and pre adjusted. A bit sloppy of Pacific antennas.
Hello Rob, I enjoyed watching the video. 73 AE4OY William Peacock 🦚 EM-81uf SOUTH EAST GEORGIA 🤓
So Rob, could you possibly let us know what the lengths of each segment wound up being after you had it tuned for the final time? Great video sir!!! 73!
The inner wire ended up being about 15'9' and the outer wire 8'10".
@@SevenFortyOne Awesome, thanks. I may pick one of those up to try out. I've been thinking about working some portable lately. Thanks for the video and all the info! 73!