W6SD Bob Brehm AK6R on End Fed Antennas - August 20, 2021

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  • เผยแพร่เมื่อ 27 มิ.ย. 2024
  • Bob Brehm, AK6R, is the Chief Engineer at Palomar Engineers, Inc., which makes antennas and RFI control devices for the ham, commercial and military markets. Bob here discusses the many advantages of non-resonant end-fed antennas.
  • วิทยาศาสตร์และเทคโนโลยี

ความคิดเห็น • 62

  • @thormusique
    @thormusique ปีที่แล้ว +9

    This was one amazing presentation! I learned a boatload of stuff (a big boat at that!) and had questions answered that have been percolating in my head for years but didn't even know how to ask. Not even kidding. It's wonderful to hear from such an articulate person who clearly knows his stuff, rather than from the armchair 'experts' one can find all over The Interwebbs these days. Cheers!

  • @kellmannorman3717
    @kellmannorman3717 ปีที่แล้ว +4

    ***** 5 STAR ***** presentation on 01/02/2023 @ SLARC. paid attention & got the answers to my questions about EFHW antennas, installations & operating differences. thank you AK6R.

  • @gregoryburbage7906
    @gregoryburbage7906 2 ปีที่แล้ว +5

    This is the only video that solved all my questions on my non resonant "longwire" antenna. Now I feel good about my set up performance and I use the torid coax wound choke you picture. Thanks a bunch!

  • @cwguy8960
    @cwguy8960 ปีที่แล้ว +1

    Great presentation - thank you! Never thought about the coaxial switch sharing multiple braids issue - make total sense!!! So good to learn from a true expert. 👍

  • @hankhardisty9433
    @hankhardisty9433 ปีที่แล้ว +1

    I have been looking at videos all day! I have finally found one which gives me a good perspective not only in tuning random end-fed wire antennas but also gives me a good understanding of the theory behind it. Thank you.

  • @olehelgerson7996
    @olehelgerson7996 ปีที่แล้ว +1

    As an operator slowly and carefully heading toward HF, this was very useful presentation. In terms of organized material and effective delivery? Excellent work! Thanks! 73s KI7MBR

  • @chiphungerford
    @chiphungerford ปีที่แล้ว

    Thanks for posting, there is a great wealth of info here I am sure I will be coming back to watch this one multiple times.

  • @fubarsnafu4994
    @fubarsnafu4994 7 หลายเดือนก่อน

    Absolutely nailed it! Thank you... Best presentation to date by far on the web!
    Palomar has been part of this arsenal for many many years. Years before I even had my ticket.
    As usual fashionably late to the meet but glad I caught this one ✌

  • @Tommy_Boy.
    @Tommy_Boy. 2 ปีที่แล้ว +1

    Really great presentation. Thoroughly enjoyed it! It was right in my wheelhouse. Thanks very much! 👍📻⚡️

  • @G0ogs
    @G0ogs 2 ปีที่แล้ว +3

    Very informative, thanks for sharing this information.

  • @survivalcomms
    @survivalcomms ปีที่แล้ว

    Excellent presentation ! Thanks for sharing !

  • @captainwyattoutdoors1636
    @captainwyattoutdoors1636 ปีที่แล้ว

    This is a GREAT video! I love Palomar Engineers' products.

  • @floridasaltlife
    @floridasaltlife 10 หลายเดือนก่อน

    Love wire antennas, watched to understand the differences in efhw and efrw, very happy with what was offered. I use efhw currently.

  • @hubercats
    @hubercats 2 ปีที่แล้ว +2

    Great presentation! - Thanks for sharing it. - Jim (KK7CSC)

  • @gravestonemyth
    @gravestonemyth ปีที่แล้ว +1

    I just watched this again after fighting a noise battle with an 80M EFHW. Afterward, I hung 84' of wire as an inverted L up about 25' using a 9:1 wound on an FT240-43 core. I need to add more counterpoise to see what happens to the SWR. Wow... so quiet and yet versatile. Thanks for promoting the end-fed random wire!
    I think the iron core toroids work well from 20M up, with ferrites doing great all the way down to 160.

  • @CC-hk6vy
    @CC-hk6vy ปีที่แล้ว

    Fantastic talk!

  • @kenwing6196
    @kenwing6196 6 หลายเดือนก่อน

    Wire Length (feet) 68-73, 85, 92, 102, 120-125 Minimum Coax Length (feet) 65

  • @mikesmithg0rfd356
    @mikesmithg0rfd356 ปีที่แล้ว +1

    thank you.

  • @GordonHudson
    @GordonHudson 9 หลายเดือนก่อน

    Discovering RF choke at the transceiver end of things really reduced my receive noise level. I made one from 30 (!) 6mm ferrite beads threaded onto a piece of good quality RG58 with a gap between each and then heatshrunk over so its like a flexible patch lead. I combined that with a G3SEK mains filter and ferrites on all the switch mode 5v power supplies in the house. Got my noise level down from S8 to S2 on HF. GM4SVM

  • @nc4tn
    @nc4tn 2 ปีที่แล้ว

    I’d love to see the PT-340 Tuner-Tuner come back! Really nifty device for adjusting manual tuners without transmitting.

  • @kirkp_nextguitar
    @kirkp_nextguitar 9 หลายเดือนก่อน +1

    At 42:25 (Question #1) he says EFHW antennas don’t work on odd multiples of the fundamental frequency. That is incorrect.

  • @kenwing6196
    @kenwing6196 6 หลายเดือนก่อน

    I run the Bullet 9:1 with an 85' wire, 20' vertical, 65' horizontal (inverted L), with two 15' radials, and choke on the coax at 50'. Works great.

  • @rtoledo2
    @rtoledo2 9 หลายเดือนก่อน

    WOW , Bob just got your 71' antenna , that bullet picture does not do justice to that bullet, I can tell it's quality just by the weight of the goodies in it, and that Maxi -chocker is also awesome, I can tell you put quality ferrites in it. I will post once I get it installed. runs circle around the first radio-wazs I got 2 years ago at hro wen I bought all my gear from Bob in Anaheim.

  • @shawnp6653
    @shawnp6653 2 ปีที่แล้ว

    Fascinating presentation. I need the non-res efhw antenna - probably in my attic. not sure how to fit that much coax in the attic though - can it zig-zag across the attic floor before getting back to radio?

  • @ErnestGWilsonII
    @ErnestGWilsonII 2 ปีที่แล้ว +1

    Wow, this video was very helpful!
    Where can I get more information on all the various lengths of wire and counterpoise that have been tested with those SWR graphs shown in the video? Is there a database of SWR readings with various wire lengths we could review?
    73 W3GUY Ernie

  • @mathepilot7869
    @mathepilot7869 ปีที่แล้ว +1

    Thank you for the valuable information.
    Where I get your RFI course you mention

  • @donaldsmith3048
    @donaldsmith3048 ปีที่แล้ว

    A good RF ground sometimes is good to cut out noise. A RF choke and a surge suppressor with a good ground just before going inside, can block out a lot of noise. Plus it helps with surges from near by lightning or solar flares. Nothing can help if lightning hits your antenna! It can form glass around ground rods! That is how hot they get!

  • @DK5ONV
    @DK5ONV 2 ปีที่แล้ว +4

  • @FindLiberty
    @FindLiberty 2 ปีที่แล้ว

    PRICELESS

  • @cougarmeat8803
    @cougarmeat8803 ปีที่แล้ว +1

    What about the position of the counterpoise with respect to the antenna wire? In the narrow confines of a yard, the area where the ant. can run is the same area the counterpoise can run - under the antenna. Or, two shorter cp wires could run at 90 degrees from each other (starting in the corner of a yard.

  • @edwardlouisbernays2469
    @edwardlouisbernays2469 2 ปีที่แล้ว +1

    W5SD I think ran for Mayor here in San Francisco, I contacted him on 40 Meters in 1999 [I am W5AWG] I also lived in Tijuana and spent loads of time at HRO in San Diego, 2000-2005 When Shorty was living in Vista. 73 om My Age is 73 also. Gee Whizz

    • @davidbailey8981
      @davidbailey8981 ปีที่แล้ว +1

      Happy hi I Vice cycle h I C h Gigi g C I to h u b b hhiu

  • @gravestonemyth
    @gravestonemyth ปีที่แล้ว

    I wonder if Paloma’s uses iron or ferrite cores. The T130-2 or T200-2 core is great, but typically from 40 meters on up. FT140-43 or FT240-43 go down to 160M nicely, though I need to test the efficiency.

  • @geekthesteve6215
    @geekthesteve6215 ปีที่แล้ว

    Thanks for the video. First things first, I was expecting the typical death by PowerPoint presentation but the density of the information made this anything but boring and redundant. I am in the process of putting up my tower (just 35 feet to start but I have several more sections I can add later). I also have an old but like new Icom AT-130 tuner that I was planning on putting up and I am thinking now that I want to put a non-resonant end fed antenna up with the tuner at 35 feet and counter poises of varying length running down the side of the tower with one tied into a ground stake. The wire would be one of the longer ones, minimum 155 feet (my lot is about 2,000 feet deep, dropping into a gulch, so would all be sloper). Optionally I could mount the tuner lower on the tower allowing for the vertical component. Do you have any comments on this setup?

  • @ericdee6802
    @ericdee6802 2 ปีที่แล้ว +1

    Is the the same palomar that made rf amplifiars???

  • @BikePractice
    @BikePractice 10 หลายเดือนก่อน +1

    Great vid, and covers every aspect of end fed and SWR, however, I was hoping for some information on radiation patterns relevant to end fed antennas, there is a controversy about end fed radiating toward it's orientation, vs broadside. Would love to hear your thoughts, 73 W6WR

  • @DucatiMTS1200
    @DucatiMTS1200 ปีที่แล้ว +1

    Best presentation I've seen for a long time. Thanks for taking the time and effort Bob. Also well done to the Fernando Valley ARC . 73 de GI8WFA.

  • @RobertMacCready
    @RobertMacCready 2 ปีที่แล้ว +1

    Well done and informative. Thanks!!! de KQ1K

  • @HamRadioLiveShow
    @HamRadioLiveShow 2 ปีที่แล้ว +1

    Nice video. Bobs a good man. I’d like to use part of this video to help people in amateur radio.
    My TH-cam channel exists to try and help people get into amateur radio as well as license up and learn about very important things we need to know in radio. That’s where your video comes in handy.
    I’ll be sure to credit your channel in the description section and put a link to it. Also, I subscribed to your channel. Keep up the great work!
    Larry

  • @billr4267
    @billr4267 9 หลายเดือนก่อน

    Nice informative video. BUT... after I ordered an in-stock wire antenna from them, find that their customer service is nonexistent, terrible. After waiting 2 weeks for an antenna... nothing, zippo, nada, they hadn't even shipped it yet. Probably won't be buying anything else from them.

  • @dalev1319
    @dalev1319 ปีที่แล้ว

    Nice presentation, I sent multiple emails for information and help on their 71 foot end fed, never received a reply.

  • @KutWrite
    @KutWrite 2 ปีที่แล้ว +2

    Anyone know why putting the choke between the antenna switch and the radio wouldn't work? Why buy one for each antenna if one will work?

    • @CarlMadsen
      @CarlMadsen 2 ปีที่แล้ว +4

      @KutWrite - he mentions it at the end 45:20 - you'll get the noise from each coax because the switch only switches the center of the coax, the outsides are all tied together. If you choke between the switch and the antenna you isolate that antenna. If you do it for each antenna, the outside braids of each coax can't go through the switch.

  • @dvscotlandphoenixnetwork
    @dvscotlandphoenixnetwork 2 ปีที่แล้ว +1

    DV Scotland is an independent informal group of radio amateurs, mostly based in Scotland, who share a common interest in Digital / Analogue voice systems.
    Collectively we operate a number of digital / Analogue voice Repeaters / Nodes throughout Scotland, most of which are Multi-mode, operating on D-Star, DMR, System Fusion, FM modes.
    The Group also host a number of Linux servers to run D-Star XLX600 Reflector, YSF GB-DVScotland Reflector, DV Scotland DMR+ IPSC2 DMR Master Server and Allstar HUB 53937. @

  • @phurla1
    @phurla1 2 ปีที่แล้ว

    air choke 12-14 inches from the transformer feedpoint on an efhw? I was under the mpression a choke at this point could not supress the high voltage? So two chokes - one close the transformer and one further on down the coax?

    • @gravestonemyth
      @gravestonemyth ปีที่แล้ว +2

      You can use a choke at the feedpoint so long as you have one or more counterpoises

  • @zachreyhelmberger894
    @zachreyhelmberger894 2 ปีที่แล้ว

    I got this terrible noise spike that is about 5 to 10Khz wide that slowly sweeps back and forth across the FT8 band like a downhill skier who barely knows how to turn. It happens on all HF bands and I cannot seem to find the source. We are off-grid, solar powered home and at least 400 feet away from the nearest other off-grid house. It does not seem to matter whether it is day or night so I do not think it is the solar charge controller/PV panels. I hope it is NOT the inverter 'cuz we kinda need to have that on all the time.
    I tried putting all kinds of rings and toroids and snap-ons but not help. I unplugged and even turned off the power strip for the WiFi and stuff but no help there either.I got a Xiegu G90, an RF choke and a 53' end-fed random wire antenna with the 9:1 un-un.
    I might have a crappy ground since I am using the third prong (chassis ground of a nearby DC power supply (that is turned off) as the ground for the radio.

    • @gravestonemyth
      @gravestonemyth ปีที่แล้ว +1

      Yeah, it’s most likely the inverter.😊

  • @richranchernot
    @richranchernot ปีที่แล้ว +1

    Great products, but very poor Customer Service. I would recommend buying Fair-Rite products elsewhere. They delay shipping unless you pay for expedited shipping and when you inquire about shipping they create a label on USPS website to make you think they shipped you order. USPS website confirms that only a label has been created, but nothing has shipped. I made multiple email requests for a response and even called customer service and left message, Nobody, including Bob or his wife ever responded. After weeks of waiting, I had to cancel my order and I purchased what I needed from DX Engineering. So sad to have to post this, but if you fail to take care of the customer, others need to know.

  • @royurick
    @royurick 9 หลายเดือนก่อน

    Wow. Talk about drinking from the firehose...

  • @johnarcher9480
    @johnarcher9480 ปีที่แล้ว

    EFHW works on even AND odd harmonics.
    80m at the very least should do 80,40,30,20,15, and ten.
    With a compensation coil, the upper bands match nicely.
    Many get 17m and 12m as well.
    And an EFHW will work far better on 80m than a random wire antenna of 71’ or anything lower than 120’
    I understand he wants to sell stuff, but he is demonstrably WRONG about EFHWs
    That said, I do own some of his chokes and Baluns. They are good quality.

  • @scott8049
    @scott8049 6 หลายเดือนก่อน +1

    secret, purchase a Palomar noise filter for $129. buy a palomar common noise choke...lol...choke? I meant joke. he already robbed me of 400+ dollars.

  • @k8byp
    @k8byp 2 ปีที่แล้ว +1

    Pointless waste of time.
    This is not the 1930s with transmitters having hi Z outputs.
    They are 50 ohm now ( very low)
    It is utterly foolish to play with such grossly mismatched hi Z antennas and matching networks.
    Same foolishness in grossly out of tune twin lead antennas.
    If you think this nonsense works, try two things:
    1. Listen on air. Note that those using kluges like end feds and G5RVs universally need amplifiers just to talk in the US.
    2. Turn the power down to 1 - 5 watts. Good luck getting out of your own proverbial back yard.
    Im working Europe 55- 59 with 1- 10W CW and SSB with PROPERLY tuned antennas. Serbia, 55 in phone.
    You wont with such kluged up antennas.

    • @k8byp
      @k8byp 2 ปีที่แล้ว

      PS the dipole graphic is wrong. That ' sine wave' theory went out the window years ago.
      Smoothly changing functions ( sine waves) can not radiate.
      Dawson, IEEE

    • @phurla1
      @phurla1 2 ปีที่แล้ว +1

      working dx ssb on 1-10watts? I'm skeptical of nref and it does appear to be a lot of tweaking. My vertical needs no tuner 160 - 10 on any frequency, but I get better reports on ssb from my efhw horitzontal.

    • @gravestonemyth
      @gravestonemyth ปีที่แล้ว +2

      I use a home brew 30’ 9:1 vertical with a 15’ counterpoise for POTA on QRP CW. It gets out great on 40 and up. I have completed QRP QSOs of 9,000 miles with this antenna. It’s a fantastic solution, though it requires a tuner. See it in action at TH-cam.com/@learnhamradio

    • @rnrbishop
      @rnrbishop ปีที่แล้ว +1

      Oddly enough worked 5w SSB both ways, tuner fed random wires over tree branches both ends a number of times. England to USA. But guess I’m hallucinating.

    • @johnarcher9480
      @johnarcher9480 ปีที่แล้ว

      Never owned an amp and my EFHW works the world.
      Your statement is false.

  • @jimbarlow2611
    @jimbarlow2611 2 ปีที่แล้ว +3

    What a fantastic presentation. Thanks so much! de KE9ZD

  • @seanprice2634
    @seanprice2634 10 หลายเดือนก่อน +1

    Ive learned so much from this video. Plain english for the layman. M7ULV