Mousie tail counterpoise for ht's

Discussion in 'QRP Corner' started by KA0USE, May 10, 2019.

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  1. KA0USE

    KA0USE Ham Member QRZ Page

    i saw an article in a back issue of a ham magazine, telling how to make one of these.
    well, my yaesu '817 is kind of an ht, and since the rubber antennas i have don't work
    well i thought i'd make a mousie tail.
    the article called for 19.3" of wire attached to the bnc mount by a large ring terminal.
    i didn't have one that size so i got the 'brilliant' idea of using a small ring terminal and
    attaching the wire to the grounding screw on the back of the radio.
    total...flop. i tried shortening/ lengthening the wire to no avail. no improvement.
    i had put the antennas on my antenna analyser to get the swr spread, and then did the
    length adjustments.

    later today i'll attach the mousie and antennas to my analyzer and see what happens.
    it has a grounding lug.

    feedback?
     
  2. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    Well, what you are referring to is a 'counterpoise"/radial.

    The specific dimension is 1/4 wavelength at 2m. So, it is no surprise that it has no effect for use at HF. It works just fine with my HT's. I always carry one in my pocket when afield.

    Cut your counterpoise/radial to the appropriate 1/4 wavelength for the band(s) you want to operate and you should have better luck.

    Let's review the math. Formulas approximating length including End Effect. Memorize them and you will always be able to quickly throw together a resonant antenna anytime!

    1/2 wavelength = 468/Mhz = Feet

    1/4 wavelength = 234/Mhz = Feet (note this is 468/2!).

    p.s. The foregoing assumes you are using an unbalanced whip (vertical) antenna at the back of your radio. If you are using a balanced antenna like a dipole (or a vertical at a distance fed with coax), then the counterpoise/radial will have little effect since it is carrying little or no current.
     
  3. KA0USE

    KA0USE Ham Member QRZ Page

    wow! that was a quick response!! i thank you!
    i guess i wasn't clear as to frequencies. the tail IS for 2m.
    the 19.3" is ~1/4 wavelength for 2m, my head hurts. will go fuss with it some more.
     
  4. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    Well, the radio is already of substantial size, especially compared to the average miniature HT's used today. So, the radio chassis may already provide a substantial RF counterpoise, such that adding a wire is not significant.
     
    KC3JIN likes this.
  5. K0MDW

    K0MDW Ham Member QRZ Page

    I find a proper cut counterpoise allows the use of the mini whips for hf on the 817... Without them, nearly useless. 2m, never thought to try...
     
    KA0USE likes this.
  6. N8AFT

    N8AFT Subscriber QRZ Page

    RADIO 101...
     
  7. W7UUU

    W7UUU Super Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Why do they use the silly term "mousie tail" and not just call it a counterpoise?

    nothing mean meant to the OP - but in a technical hobby, why not use the technical term?

    I don't get that

    Dave
    W7UUU
     
  8. W7CJD

    W7CJD Ham Member QRZ Page

    ..not so long ago, it was called a "tiger tail".

    No?
     
  9. W7UUU

    W7UUU Super Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Yep. Another silly name for the proper term: "counterpoise"

    Why not use the proper name? I just don't get that... these are opportunities to teach new hams about concepts and terms. Not a time to teach silly little kid words like "Mousie Tail" etc.

    Dave
    W7UUU
     
    W7CJD likes this.
  10. AA5CT

    AA5CT Ham Member QRZ Page

    The BIG Motorola HT200 (introduced in the early 1960's) had big back covers made of ... must have been aluminum. The HT200 was a little slimmer than a brick, but had about the same outline.

    A good grip on the radio with the right hand grasping the back radio placed the bulk of one's hand in good capacitive-coupling position on that back metallic cover ... and little wonder, if weak into a repeater, pointing one's elbow down while facing the repeater (and holding the radio just a little higher than normnal) resulted in a stronger signal into said 'machine'.
     

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