Thanks for the information on the Hairpin Match. I still run a gamma match , but would like to upgrade. I just found your channel, left a like and am following. Have a great weekend, 21 Old Radio Night.
The logic of a Gamma over a Hairpin is the Gamma's benefit when using an unbalanced line. Coax is an unbalanced line that Gamma's are specifically made for. You needs an unbalanced method to decouple the RF energy properly. If you don't decouple fully you'll greatly increase the likelihood of developing unwanted antenna currents. The coax shield is ground and it must be terminated as ground. That is what a Gamma does. It not only steps up the impedance of the element but becomes an unbalanced to balanced feed method for coax. RF is stupid as it can not tell the difference between a conductive antenna element or the conductive shield on a piece of coax. If you want the coax shield to be part of the antenna then use the hairpin to take the shield off of ground potential. If you want the coax to fully decouple put the coax at the ground potential of the boom by using a Gamma. *The capacitance tube in a Gamma has no measurable restriction on the transfer of RF power.
That's a pretty cool flat side antenna you built there.. You cannot beat the DirecTV pin.. I'm working on a six element quad and I'm going to direct feed it too.. or may go through a KB balance.. For a better distribution of the signal.. just watched your video keep up the good work.. have a great evening.. curtis in Kansas City Missouri 73s...
Seems youre putting the hairpin on the wrong end of the M107, also you stated with a gamma match only one side of the driven element is excited. Youre cutting the driving element in half and grounding the other side side, help me to understand why that is not exciting one side...thanks!
After many years of using verticals I have just recently purchased my 1st 3 element Yagi, not up yet but looking forward to a better Rx/Tx & Dx. 407 Mcr 🇬🇧 👋
I watched your video and it is very interesting i am going build a 4 element can you share everything i would need to buy as to the hairpin system.i have ssen some videos that say you need a blum is that so.thanks for any info.i have also subscribed to your channel get any updates.
I looked at your video, not too much information. If we cut the driven element then you have to readjust all the elements. Please more information. Thank you.
Could you show us newbys How to make and parts needed for the hairpin set up you have on this beam ??? You didnt have a contact info to email you so we went this way, Thank You for your time. Dave 672 SW Kansas
Why wouldn't this be considered a direct rf short as both the center lead and ground braid are in direct contact with each other after leaving their connection points and making contact at the mast ? Could you give us a detailed explanation and diagram as to how this actually works ? You called it a shunt. Thanks, Billy
Would like to do this to my seven element what did you use for the plastic on the driver and is it correct they're not touching in the plastic or the elements are touching their just your adjustment rod thank you
@@cogentradiosgroupllc1479 No part of your driven element should go to ground. When you put power to a driven element that is going to ground you heat up the entire antenna the mast the tower everything that it’s connected to Only your radio equipment should be grounded.
@@travishorn1847 thats interesting, I have been doing this for over 45 years and never heard of this approach, do you have any white papers or technical writings on this concept, I would love to see it.
@@cogentradiosgroupllc1479 if you can insulate that set up on your driver from your boom and still manage a good match for your feed line you will notice a huge difference. 😎
@@cogentradiosgroupllc1479 only from experience I can have more info on this for you later I’m a Truck Driver out on the road right now. But I will be using that on my next build on my M108 I prefer that over a normal gamma. Now in getting that away from ground might take a 75 ohm coax so many feet to match not sure but I will find out. 73,s I don’t judge just try to help when I can.
@@jeffhicks2070 I won’t disagree with you now I’m eating crow , cause I’m having to attach one also to get a lower SWR match on my 7 element Some antennas get away without it going direct fed , not this 7 element. So , I stand corrected and take my medicine 👍
The circuit can't excite half of the driven element. Think about it. The circuit is looking for something that is electrically resonant. A full size 1/2 element is resonant. Half of an 1/2 element is not.
How do you calculate the two hairpin lengths ? Are they 1/8th or 1/4wave of freq? I'm interested in a 12/11/10m centre fed dipole with hair pin matching so DC shorted. Yes balanced is a better way of matching. Rob.P
Im new to the beam, fixing to order a maco 4 r 5 element. Wanting to do away with the gama and do some type of direct feed. And suggestions? Really could use some advice and also point me in the direction to someone that could build the direct feed for me. Really would appreciate any help
Yes. A 1:1 choke balun designed for the desired frequency. Edit: Because the antenna is now a split element, meaning it's a balanced antenna. Fed with coax, which is unbalanced, it needs a choke balun.
I have been researching this and decided to go this way . I have a small yard -air space area to work with will this do good on a 3 element or 4 element. Thee absolute biggest i could go would be 5. Any insights or thought iput would be appreciated. I love this video ,i am now excited to do this. I have a 170 feet of tower out side now . I want to put the beam at approximately 100 feet give or take 20 feet. Thanks in advance. 199 florida georgia line. 73s
