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Thread: 160/80/60/40/30M Vertical DX Antenna

  1. #1

    Default 160/80/60/40/30M Vertical DX Antenna

    160/80/60/40/30M Vertical DX Antenna

    The 80M antenna is essentially a dipole, with the coax center conductor going to the vertical element via a trimming coil and the coax shield going to the radial element via a trimming coil.
    The trim coils adjust the electrical length of the elements. There is a current balun between the radio coax and the antenna connections.

    1/4 wave on 3.5 mhz is 8' longer than 1/4 wave on 4.0 mhz.

    My ground mounted antenna is 55' high and has 5' of wire to connect to the trim coil, which is tapped at 2.6'. My target frequency is 3573 and with some patience and a antenna analyzer I can trim my antenna for a SWR of 1.0:1. My trimming coils are 22 turns of #18 bare copper wire wound on a 1" PVC form, roughly 4 turns is equal to 1'. I am using good quality alligator clips to trim with and have never had a problem, even on 160, but I only run 50W digital. My radial started out 1/4 wave long but it has been chopped on, my 80M ant tap is on turn 10 of the trim coil. The radial wire goes up and down on the garage wall before exiting and running along the eaves for 40'. How the radial is run isn't critical, but it should be over 3' off the ground and roughly horizontal. My radial coils are on a shelf by the bin that holds the other antenna components.

    So the electrical length of the vertical element = ant + wire + coil = 62.6', the radial would be of
    similar length, and it all resonates on exactly 3573 khz with a SWR of 1.0:1 and 1.5:1 bandwidth of 175 khz. That's it for 80M.

    There is interaction between the 160 and 80M radials, so switching them is necessary and I ganged 2 automotive type 30A relays to do that. Energized selects 80M antenna tap and 80M radial, deenergize selects 160M tap and radial. At the loose end of the 80M trim coil is soldered a 20 turn close wound coil of #18 enameled wire on the 1" form, then slide it off the form and hot glue it a lot. The 160M antenna trim coil is 22 turns #18 bare wire, for 1840 khz my tap is on turn 18. Like the 80M antenna, by patient trimming the SWR goes down to 1.0:1. If your 80 and 160M coils are in a neat row, then make sure they are all wound in the same direction. The 22 turn 80M trim coil soldered to the 20 turn fixed coil soldered to the 22 turn 160M trim coil, all in series. My 160M radial element leaves the garage and is stapled to a wooden fence. It started out as 1/4 wave long but got chopped on to its current length. That's it for 160M.

    I ganged 2 automotive 30A relays and use them to switch a "L" match tuner in or out, one end of the coil switched to the coax center conductor and the applicable tap and capacitor switched to the antenna on 80M, the free end of the cap goes to the coax shield. My tuner coil is 40 turns #18 bare wire on the 1" form, with the 30M tap on turn 6, 40M tap on turn 9, 60M tap on turn 26. I bought a good selection of silver mica caps and was able to find a cap and tap on all 3 bands and the rig's SWR meter never moves unless there is a problem.

    A 12 channel wireless remote lets me change bands from the shack 30' away from the antenna, and cost around $25 on ebay, same with the silver mica caps. The little relays on the remote board gave me problems so that is why the 30A automotive relays, however the remote board relays haven't caused a problem yet switching the tuner band taps or capacitors. The relays are programmed as latching, press 3 on the remote, relay 3 latches, press 3 again and it unlatches. Another wireless remote relay is in the shack for a local display using a LED DIP and a resistor. If things get scrambled, turn off the display LEDs, then reset the remote relay. A 1/4 wave radial is required for both 40 and 60M, and no trim coil is necessary. My radials are #18 enamel that make their way out of the garage, then are hot glued to the stucco outside the house with 1' separation. My setup didn't require a radial on 30M.

    I hot glued the ant and tuner coils to a piece of plastic cutting board that fits inside a plastic bin, and the board is hinged so that both sides can be accessed or completely removed. My antenna coils are on the right side of the board, the tuner coil on the left. The board itself is 10x12x1/2" and sheet metal screws and hot glue work well with it. When I open the plastic bin, the coils and gator clips are accessible. Swing out the board, and the remote relay 3x5" box is mounted on the back, between the two coils. Everything in the bin runs on 12 VDC via a reset switch. I allotted 2 relays for each band, remote relays #1-6, to switch in a tap on the coil and a capacitor. Relay 7 selects 80/160M, and relay 8 selects the tuner IN/OUT. Only the 80M ant is used by the tuner.

    1/8 wave on 160M is anemic, but sure beats 0/8 wave. With no special receive antenna have worked Alaska, Mexico, Canada, most states, and I usually make a new contact when I go there.
    1/4 wave on 80M does world wide DX. My full size 80M inv vee couldn't work Europe the other night, this vertical did.
    3/8 wave on 60M does world wide DX. Finally worked Portugal here the other day, plus Africa and a slew of other countries the past few months.
    1/2 wave on 40M of course does world wide DX. I was so happy with it I added another radial.
    5/8 wave on 30M does world wide DX and I have worked a lot of it with this vertical.

    A 61' antenna looks to be the best size and still allow trimming. My 55' structure is 39' of fiberglass
    pushup pole ( bought when DXE used to stand behind their products ) attached to 16' of aluminum tubing. The actual antenna is the tubing clamped to 44' of 3mm steel cable inside the pushup pole, and there is a 4 point guy system where the aluminum tubing starts that allows the structure to be turned to get it ultra straight. My antenna exits the garage via a roof jack in the middle of the roof, so the 4 point guying was easy. The guys are 850# rope.

    My 5 band vertical will never change now, but it evolved a lot from when it first went up 7 years ago.
    I found through experimentation that treating the antenna as a dipole gave the best signal/noise plus you get the really great SWR on all bands.

    This is a typical vertical antenna with a donut shaped radiation pattern and low angle of radiation,
    great for DX, not so great on the local nets. The 1.5:1 SWR bandwidth is 160M 60 khz, 80M 175 khz, 60M 190 khz, 40M/30M whole band under 1.5:1. If you use the tuner, then do not broadband the 80M antenna as the S/N will suffer on 60, 40 and 30M. Go for high Q.

    50 watts digital and nothing fried since finalizing this current configuration a year ago. Using the
    same gater clips on all the coils for summer/winter trimming. My 160m radial on a bare wood fence was not a good idea when it rains, but the other bands don't change much with the weather.

    Shorter radiator, bigger coil will work, but why disappoint yourself? A rope between 2 structures
    at 65' would be perfect, 10 joints of aluminum tubing with overlapping smaller tubing inside with some guying is affordable, etc.

    I mentioned having relay problems I gave up on the remote tuner and set it up for a "T" match tuner in the shack. When all was tuned, the typical noise level on 40M barely bounced the S meter, whereas when I was using the remote tuner, the noise level was bouncing S2, a huge difference! Needless to say I tried harder to make the remote tuner work. If you draw a coax with center and shield, attach the center to the "L" coil, other end of "L" connects to the cap which goes to the shield, then draw a line straight up for 62.5' where the coil joins the cap. That is what 30/40/60M looks like, which is pretty cool. No air gaps, just solid metal and very effective.

    You don't need sunspots to work worldwide DX, when the sun goes down this antenna is ready to play all night long.


  2. #2

    Join Date
    Jan 2020
    Union, Washington

    Default Love to see pictures of this antenna and other parts

    I can picture what you described in the post but I will do better with diagrams and pictures. Have you posted these in another place?

    Thank you
    Ben Hicks K7AAI heading to General in a month

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