Welcome to Tropical band

To most people the phrase "tropical bands" bring a pretty clear picture to mind - a bunch of shirtless guys playing calypso music. But to experienced shortwave DXers those two little words express the most challenging and enjoyable part of the radio hobby. The phrase kindles memories of a DXer's best catches and favorite QSLs, of exotic stations, music and of early morning listening sessions. (Don Moore)
I like the "Tropical band" name for new 60m allocation. (OK1RP)

Effective from 1st Jan 2017 please paper QSL via OM-bureau only.


Sunday, January 16, 2011

Experimental 60m Inv Z dipole for pocket size lots

Hello,

although the 60m Tropical band is not as low as Top band for example the 1wl is still enough to have troubles with full size antennas.

For all of You with the pocket size lots for antennas there is antenna inspiration > Inverted dipole where the second half of legs are folded to "Z" letter (according to actual space on the garden)


All neccessary information are on the picture so just few comments to installation only:

- higher apex > better results
- shorter folded ends > less compromise and better results
- it's possible to experiment with folding the legs to different directions
- my feed point apex is just 7m and it seems to be low for long distance QSO
- in my QTH this antenna is more noisy than half sloper > ext. RX antenna is a must

I put it up as temporary and experimental piece to check where and how I can put the legs of my dipole on the garden. The changing of the legs and position of the dipole parts incl. the feed point is expected to reach best results for DX...

I will welcome if somebody will be so nice to make PC analyse of this configuration (in MMANA or other s/w) to let me know an idea about current radiation patterns and impedance condition...?

Current data meassured by MFJ-259 - SWR 1.5, Z=30+j4 at 5260kHz but incl. about 20m unknown cable. So data are probably not usable.

Good luck if You will try to put it up also.

73 - Petr, OK1RP

2 comments:

  1. Hi Petr, I have a coax fed dipole up at 25 feet. For NVIS propagation I have mounted it over a reflector at six feet. The reflector is 10% bigger than the dipole. The size and position of the reflector are based on what I could fit where and has not been optimised.The 60m Dipole runs North South and parallel to my 80m dipole 20 feet to the East, which may act as a reflector improving my signal/reception to the West and accounting for the large number of US stations in my log on 60m.
    Too many people give up on the band because they try to use G5RV's and other none resonant antennas. Resonant antennas can be noisy if close to built up areas and effectiveness of the station can be improved with a full size receiving loop.

    ReplyDelete
  2. Steve,

    thank You for posting it. Interesting to use reflector. I have no space to use correct beam with spaced reflector so maybe I can use similar one to Your antenna.
    Do not hesitate to call me if You will catch me on the Tropical band.

    73 - Petr, OK1RP

    ReplyDelete