Screwdriver antennas.

Discussion in 'Mobile Radio Systems' started by N0IOP, Oct 10, 2019.

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  1. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    I did some "antenna shootouts" of my own, once upon a time. Distance was 120 miles. 125 watt mobile rig. Vertical mobile whip was unreadable to weak. Mobile whip brought to horizontal was readable. Horizontal wire (around 1/4 wave length) replacing the whip was the best. Multiple freqs tried, not ham bands. Results were repeated on different occasions.

    Also tried man pack whip (no-go), man pack whip with counterpoise (readable) and dipole (strong signal). All 20 watts. Fun stuff.

    73,
    Al
     
  2. K0BG

    K0BG Ham Member QRZ Page

    I think a lot of folks here should buy an ARRL Handbook, and read the chapters on propagation. Next, download the EZNEC application, and learn how to properly model their mobile antenna. Then, review what you've written here.
     
  3. N0IOP

    N0IOP Ham Member QRZ Page

    If something works in the field but is theoretically impossible, then the theory needs to change.
     
  4. K0BG

    K0BG Ham Member QRZ Page

    The issue isn’t the theory. It is the understanding of the theory which is in question. In other words, you’re taking a phenomena and applying an anecdotal reason. But in this case, the reasoning is incorrect.

    As I alluded to, the ARRL Handbook has a very good treatise on the subject. You might look at Rudy Severns’ (N6LF) article on same as well.
     
  5. N3UML

    N3UML XML Subscriber QRZ Page

    i recently purchased a Diamond Screwdriver antenna with a West Mountain Target Tuner from Dx Engineering and i Have used a screwdriver in the past but it was a home built screwdriver using a Black and decker drill motor the copper fingers that contact the coil were marginal at best when i bought that one. i remanufactured the fingers and it worked fairly well but still i wanted something better. Well let me tell you if you want something with simplicity of use the Diamond meets all my needs. im not real big into ^ meters or 10 Meters so i chose the longer whip and have had wonderful results. i have worked as many stations in Europe on 75 as i have worked on 40 or 20. dont get me wrong i think the band conditions helped and hopefully the sunspot cycle is on the way up it says it is according to many sources but time will tell. But the tuner being inch and a half by 3 inches a piece of Velcro and it mounts nicely yo the dash and with 200 presets it works really well. on 75 it takes a whole lot more presets to accurately cover all frequencies on 75/80 where 40 and 20 tou can just about cover the whole band of each with only a couple presets on each band but i think i only have 100 presets copied. hopefully the sunspot cycle is on the way up then i may throw another 700 onto the mix and buy another one of each of these and set them up for 6, 10, 15 on up to17,20,maybe even 40 ill experiment with this idea using the shorter whip to do my tests. in the past i have tried hamsticks and hustler resonators which both work well if you want to use multiple antennas. Hope this hopes somebody out. 73 and happy dxing Allan N3UML
     
  6. KD2AZI

    KD2AZI XML Subscriber QRZ Page

    My first screwdriver is the Yaesu ATAS, and so far I'm getting a favorable SWR on 40, 20, 10 meter bands though it's not very responsive. Sometimes I press the TNR button and the indicator flashes, and the motor doesn't turn. It may take a couple of minutes for it to activate and find a sweet spot.

    I purchased a longer whip at a recommendation from another Ham, though decided not to install it. The 62" whip is 1/8" diameter and thus very stiff and heavy, and not sure the ATAS mount would be able to handle it long-term.

    It has not yet failed, except for the typical mobile antenna problems such as water, dirt getting in there, loose connections, etc.
     
  7. KK4YDR

    KK4YDR Ham Member QRZ Page

    I've got a scorpion also. Havent used it in 2 years. But it's an absolute outstanding antenna.
     
    AJ5J likes this.
  8. KN2U

    KN2U Ham Member QRZ Page


    My first screwdriver was also an ATAS and had the same "getting lost" issue. I solved that by manually tunig first, then it remembered. I bought the 62" whip and drilled the hole out - easy to do and it gave me about 2 more S-units on received signals. No problem handling the larger whip. I later found a used High Sierra 1800Pro, then an old friend gave me his for parts. It is also is good condition. The HS works much better than the ATAS, based on the number of relies and signal reports I get, so I will sell the ATAS ASAP. The ATAS is a great compromise antenna and using it with one of the Yaesu rigs, it's convenient when changing frequencies.
     
  9. KD2AZI

    KD2AZI XML Subscriber QRZ Page

    That's good to know that the ATAS will handle the heavier whip - I'll give it a try.
    As far as the High Sierra, do you have to add an auto-tuner to the set up..or do you tune it manually?
    73
     

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