Hello Dave, enjoy your channel! I'm really impressed at how good the EFHW is. I have a homebrew up in an Inverted V configuration too. Up and over a Maple Tree. There is very little difference between it and my 1/2 wave Inverted V Dipole that's at 30'. I have another EFHW I put together that's set up like a Linked Dipole that I use camping. It's 40 -10, but it has a bullet connector on the end w/ strain relief and I just plug another section of wire into if I want to make it an 80 -10 version. N9XFX
Dave I hv a My antennas 40-10, extended to an 80-10. A ground rod was placed beneath the box. From the ground rod, I used an alligator clip and 14 gauge wire, which I ran on the grass, parallel to the antenna wire(134 feet). The difference, especially on 160 and 80, is an s unit or two. I am always being told what a nice signal n audio is coming from the antenna and my 7300. This reflector wire or counterpoise wire, seems to do the trick. I hope others try this on the already, fantastic‘My antennas’ antenna😁. The kicker is: Along with my trustee Mfj-939 tuner and the counterpoise, I work 160 nightly, with good results throughout the northeast from my location in so Connecticut. Just thought u wld like to know. Billy
YO: The engineers who developed this antenna and EFHW antennas like it have provided technical instructions. The instructions absolutely do not indicate use of coax as a counterpoise. The developers outlined in the instructions the setup and performance parameters. This is: Ground the antenna with a "short" ground wire. Secondarily, you have the option to use a quarter wave counterpoise. The instructions do not say to use your coax as a counterpoise. For anyone looking to deploy an EFHW antenna as a primary antenna you need to ground it and then test it with an antenna analyzer. If the SWR is high or you have low RF gain then test the antenna with a counterpoise. Everyone using one of these antennas should absolutely be using a common mode choke at the antenna feed point. It does not go at the radio. This things comes with a 49:1 transformer that produces upwards of 5000 ohms and needs to be choked out and ground immediately. Depending upon how you deploy the antanna (height and style) you then need to adjust the performance with a counterpoise.
Endfed dipole? Really? You are mixing up two different things here. Dipoles can never be endfed, it’s in the definition of things. Just like an Apple is not a pear!
If my random wire antenna is grounded, do I need a counterpoise? Conversely, if I have a counterpoise do I need a ground? And is it okay to have both a counterpoise and a ground?
Excellent explanation. I have the Vibroplex Shotened 80-10 and use 55’ of the feed line into a 1:1 choke then lightning arrestor. The antenna is rated at 1KW ICAS. Can anyone explain what 1KW ICAS is equivalent to PEP? I’ve looked around but can’t find much info on ICAS. Cheers Jim
I have 3 EFHW in different orientations and have worked all over the world with them. Not much different than a dipole on its fundamental frequency and it works the even and odd harmonics as well.Just ground the outer shield of your coax before it enters the shack. No problems here
The secondary of the transformer needs to have both terminals connected to *something*. If you do not, then it isn't a transformer, it is just a capacitor between windings. Ideally it is simply grounded. There's a big difference between high voltage and low current (what you have at the ends of a dipole) and NO current which of course will also be no voltage. These things typically use the shield of the feed coax and people simply hook a wire to the high-turns side of the transformer, but there's the SAME voltage, opposite phase of course, on the other side of this high-turns transformer. If your radio isn't grounded, guess what? Whoever is operating it could get zapped. However, there is so much bad information available that do it however you like and if you get zapped you'll know why.
David, if I were to use my aluminum rain leaders/gutters as an antenna for HF, would I need a counterpoise, and if so, how would I determine the correct length for it? Thank you!
Use (and encourage the use of) the correct terminology: Dipole molecules, dipole charges and dipole antennae are, by definition, TWO sided. End-fed antennae are MONOPOLES which must be operated against a counterpoise (a ground plane or a radial system) to achieve anything like an acceptable efficiency. EFHW antennae are be attractive because they are simple and readily available, but they are a less-than-perfect compromise between simplicity and efficiency. It should be pointed out--especially to newbies-- that a resonant half-wave center-fed dipole fed with coax or a random-length dipole center-fed with ladder line and a "tuner" will both run rings around an end-fed wire with a unun and an inadequate radial system.
So, you are saying that a dipole antenna MUST be fed in the center to be considered a dipole??? Can you please quantify your statement about how a center fed halfwave dipole "running rings around" a similarly configured end fed halfwave antenna?
You are conflating a physical dipole (i.e., two-sided) with an electrical dipole (two opposing polarity voltage nodes). An EFHW is electrically a dipole antenna at its fundamental resonant frequency. As such it is no worse or better than any other dipole antenna, for any given physical configuration, at its fundamental operating frequency. When operating on a harmonic frequency, the EFHW becomes a multipole antenna with a radiation pattern different from a dipole at the same frequency and physical configuration. In this respect, a dipole antenna resonant at the fundamental frequency of an EFHW's harmonic frequency may offer an advantage or disadvantage, depending on one's operational objective.
In the standard engineering textbook “Antennas” by John Krause (W8JK), dipoles are ALWAYS presented as CENTER-fed. The only end-fed antennas mentioned are operated with a FULL counterpoise. A counterpoise is mandatory for end-fed antennas. EFHW’s that utilize a single-wire and/or the feedline as a “counterpoise” will always be inferior to one with a full radial system (or to a center-fed half-wave (or longer) wire).
@@billbrown3414 The IEEE states in IEEE 100-1984… "dipole antenna (antennas). Any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole." Given that statement from IEEE, and also “Half-Wave Dipole Antenna. A dipole whose electrical length is half a wavelength and is formed by a straight metallic radiator, one-half wavelength long, whose diameter is small compared to its length, so energized that the current has two nodes, one at each end, producing maximum radiation in the plane normal to its axis. [4]"....Calling an end fed halfwave a "dipole" is NOT incorrect as you have suggested.
@@billbrown3414 Have you tried modeling a center-fed, off-center-fed and EFHW with EZNEC or some other antenna modeling software? If you do, you'll find there is virtually no difference in radiation pattern or efficiency at the fundamental resonant frequency. For the EFHW, the relatively small counterpoise carries negligible current; i.e., it's a very high impedance feed-point. On the other hand, a true monopole (resonant or non-resonant) antenna typically has a low to moderate impedance feed-point, respectively -- thus, the need for a counterpoise that can efficiently sink or distribute relatively high current. Counterpoise current distribution pattern isn't too important for a random wire antenna; but for a ground mounted resonant or non-resonant vertical monopole, it's important to achieve a uniform radiation pattern and optimize efficiency.
Hello Dave! Uncle Guenter (ME) is a huge fan of your youtube channel and I really love the EFHW 49:1 antenna. The One I own is homemade by a freind of mine I support him testing his home brew products. He got a ebay shop selling his wire antennas on ebay germany. He became this busy in building antennas that he ain't got no time to get radio active (cw'ing or keying up micorphones) My EFHW allowed me to pretty much talk to the whole World spreading the Waves nearly into every nation. So the Person that receives your giveaway EFHW will be a lucky son of a gun to hold something in his hands that garantees him pleasure and fun for hours over many month and even years as a base antenna as well as for portable duties. Thx for your great documentary videos Mr. Casler. Therre's a lot of interesting stuff you shared with the HAM Radio World. Keep up good work & have a peaceful sunday. 73's de Your Friend Uncle Guenter from the German Frontier. (bump-bump)
"Ground is Ground. Electrons go there to Die". Yuk-Yuk!
If your coax cable is fairly short - could you use it as your shack connection to RF ground?
Hello Dave, enjoy your channel! I'm really impressed at how good the EFHW is. I have a homebrew up in an Inverted V configuration too. Up and over a Maple Tree. There is very little difference between it and my 1/2 wave Inverted V Dipole that's at 30'. I have another EFHW I put together that's set up like a Linked Dipole that I use camping. It's 40 -10, but it has a bullet connector on the end w/ strain relief and I just plug another section of wire into if I want to make it an 80 -10 version. N9XFX
Dave
I hv a My antennas 40-10, extended to an 80-10. A ground rod was placed beneath the box. From the ground rod, I used an alligator clip and 14 gauge wire, which I ran on the grass, parallel to the antenna wire(134 feet). The difference, especially on 160 and 80, is an s unit or two. I am always being told what a nice signal n audio is coming from the antenna and my 7300.
This reflector wire or counterpoise wire, seems to do the trick. I hope others try this on the already, fantastic‘My antennas’ antenna😁.
The kicker is: Along with my trustee Mfj-939 tuner and the counterpoise, I work 160 nightly, with good results throughout the northeast from my location in so Connecticut.
Just thought u wld like to know.
Billy
YO: The engineers who developed this antenna and EFHW antennas like it have provided technical instructions. The instructions absolutely do not indicate use of coax as a counterpoise. The developers outlined in the instructions the setup and performance parameters. This is: Ground the antenna with a "short" ground wire. Secondarily, you have the option to use a quarter wave counterpoise. The instructions do not say to use your coax as a counterpoise. For anyone looking to deploy an EFHW antenna as a primary antenna you need to ground it and then test it with an antenna analyzer. If the SWR is high or you have low RF gain then test the antenna with a counterpoise. Everyone using one of these antennas should absolutely be using a common mode choke at the antenna feed point. It does not go at the radio. This things comes with a 49:1 transformer that produces upwards of 5000 ohms and needs to be choked out and ground immediately. Depending upon how you deploy the antanna (height and style) you then need to adjust the performance with a counterpoise.
Endfed dipole? Really? You are mixing up two different things here. Dipoles can never be endfed, it’s in the definition of things. Just like an Apple is not a pear!
If my random wire antenna is grounded, do I need a counterpoise? Conversely, if I have a counterpoise do I need a ground? And is it okay to have both a counterpoise and a ground?
do all end feed half wave vertical antennas radiate down the coax even if they are base loaded.. if theres no ground radials
Hmmmm I've never had a counter poise.
Ground is where electrons go to die. Got to remember that one!!!
I've never laughed so hard.
I need to subscribe to his Patreon channel so I can get a kick out of the jokes a few days earlier.
If true that would mean electrons have a positive charge!!
love it!
Great review and explanation! Thank you
what's the frequency, Kenneth?
Excellent explanation.
I have the Vibroplex Shotened 80-10 and use 55’ of the feed line into a 1:1 choke then lightning arrestor.
The antenna is rated at 1KW ICAS.
Can anyone explain what 1KW ICAS is equivalent to PEP?
I’ve looked around but can’t find much info on ICAS.
Cheers Jim
I have both the 75-10 version and the 40-10 meter version (the latter is one of my portables) and they work great!!!
Totally lost me
Love the EFHW system. The information you gave is spot on. Nice job
I always look forward to your Ask Dave sessions. How many question do you get every week and how do you determine which ones to make a video on?
I have 3 EFHW in different orientations and have worked all over the world with them. Not much different than a dipole on its fundamental frequency and it works the even and odd harmonics as well.Just ground the outer shield of your coax before it enters the shack. No problems here
A TYPEWRITER on the back desk?
I already had envelopes and stamps. It was just easier.
This video was so helpful. Thank you!
EFHW + counterpoise = dipole.
not exactly EFHW.
The secondary of the transformer needs to have both terminals connected to *something*. If you do not, then it isn't a transformer, it is just a capacitor between windings. Ideally it is simply grounded. There's a big difference between high voltage and low current (what you have at the ends of a dipole) and NO current which of course will also be no voltage.
These things typically use the shield of the feed coax and people simply hook a wire to the high-turns side of the transformer, but there's the SAME voltage, opposite phase of course, on the other side of this high-turns transformer. If your radio isn't grounded, guess what? Whoever is operating it could get zapped.
However, there is so much bad information available that do it however you like and if you get zapped you'll know why.
Awesome work again Sir.
David, if I were to use my aluminum rain leaders/gutters as an antenna for HF, would I need a counterpoise, and if so, how would I determine the correct length for it?
Thank you!
I'm not Dave but yes you need the other half of the antenna which is what a counterpoise is
for length of the counter poise you want it a quarter wave for the frequency your on you can have multiple lengths simultaneously for dif frequencies
Augies? What's that?!?
End the Fed yes, but I have no ill will toward the Polish.
Di(e)Pole ok, I get it now.... (dipole)
Thanks for your help! I passed my technician test yesterday, with some help from some of your videos
Use (and encourage the use of) the correct terminology: Dipole molecules, dipole charges and dipole antennae are, by definition, TWO sided.
End-fed antennae are MONOPOLES which must be operated against a counterpoise (a ground plane or a radial system) to achieve anything like an acceptable efficiency.
EFHW antennae are be attractive because they are simple and readily available, but they are a less-than-perfect compromise between simplicity and efficiency. It should be pointed out--especially to newbies-- that a resonant half-wave center-fed dipole fed with coax or a random-length dipole center-fed with ladder line and a "tuner" will both run rings around an end-fed wire with a unun and an inadequate radial system.
So, you are saying that a dipole antenna MUST be fed in the center to be considered a dipole??? Can you please quantify your statement about how a center fed halfwave dipole "running rings around" a similarly configured end fed halfwave antenna?
You are conflating a physical dipole (i.e., two-sided) with an electrical dipole (two opposing polarity voltage nodes). An EFHW is electrically a dipole antenna at its fundamental resonant frequency. As such it is no worse or better than any other dipole antenna, for any given physical configuration, at its fundamental operating frequency. When operating on a harmonic frequency, the EFHW becomes a multipole antenna with a radiation pattern different from a dipole at the same frequency and physical configuration. In this respect, a dipole antenna resonant at the fundamental frequency of an EFHW's harmonic frequency may offer an advantage or disadvantage, depending on one's operational objective.
In the standard engineering textbook “Antennas” by John Krause (W8JK), dipoles are ALWAYS presented as CENTER-fed. The only end-fed antennas mentioned are operated with a FULL counterpoise. A counterpoise is mandatory for end-fed antennas. EFHW’s that utilize a single-wire and/or the feedline as a “counterpoise” will always be inferior to one with a full radial system (or to a center-fed half-wave (or longer) wire).
@@billbrown3414 The IEEE states in IEEE 100-1984… "dipole antenna (antennas). Any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole." Given that statement from IEEE, and also “Half-Wave Dipole Antenna. A dipole whose electrical length is half a wavelength and is formed by a straight metallic radiator, one-half wavelength long, whose diameter is small compared to its length, so energized that the current has two nodes, one at each end, producing maximum radiation in the plane normal to its axis. [4]"....Calling an end fed halfwave a "dipole" is NOT incorrect as you have suggested.
@@billbrown3414 Have you tried modeling a center-fed, off-center-fed and EFHW with EZNEC or some other antenna modeling software? If you do, you'll find there is virtually no difference in radiation pattern or efficiency at the fundamental resonant frequency. For the EFHW, the relatively small counterpoise carries negligible current; i.e., it's a very high impedance feed-point.
On the other hand, a true monopole (resonant or non-resonant) antenna typically has a low to moderate impedance feed-point, respectively -- thus, the need for a counterpoise that can efficiently sink or distribute relatively high current. Counterpoise current distribution pattern isn't too important for a random wire antenna; but for a ground mounted resonant or non-resonant vertical monopole, it's important to achieve a uniform radiation pattern and optimize efficiency.
Hello Dave! Uncle Guenter (ME) is a huge fan of your youtube channel and I really love the EFHW 49:1 antenna. The One I own is homemade by a freind of mine I support him testing his home brew products. He got a ebay shop selling his wire antennas on ebay germany. He became this busy in building antennas that he ain't got no time to get radio active (cw'ing or keying up micorphones) My EFHW allowed me to pretty much talk to the whole World spreading the Waves nearly into every nation. So the Person that receives your giveaway EFHW will be a lucky son of a gun to hold something in his hands that garantees him pleasure and fun for hours over many month and even years as a base antenna as well as for portable duties. Thx for your great documentary videos Mr. Casler. Therre's a lot of interesting stuff you shared with the HAM Radio World. Keep up good work & have a peaceful sunday. 73's de Your Friend Uncle Guenter from the German Frontier. (bump-bump)
Kenneth a Wilson, ad4jx