Wednesday, 13 July 2016

Summertime, experimentation time!

14MHz currents new design
Antenna experiments are something I'd like to do more. But life has not enough time to do it all, at least not for me. Experimenting and building antennas is not something you do in winter. And now it's summertime. One of my goals for this year is setting up de antenna tower again. But I doubt I'll manage that this year. So many other chores in and around the house preventing me to do other (hobby) things. So, I have this idea to do a simple experiment and that is improving my Alu tape vertical. How? Well, I have been thinking. One of my wishes was to have another base, in other words something that is taller as the Solarcon A-99 (4,87m) to get rid of the lineair load that makes it taller now. And I just found it when I got a broken Solarcon I-Max 2000 which is about 7,1m long. It doesn't matter it is broken, the A-99 was also broken when I got it. I'll cover it with "anti snail tape" which is coppertape instead of aluminiumtape. I expect this tape will have lower restistance and theoretically this will result in a 0,01dB improved radiation. The idea is to make the vertical 7,5m,.the radials stay at 7,5m each. I hope to get a better balance out of it this way. I've been comparing the old and new design with a free copy of EZNEC 6 and overall it looks slightly better.

Freq.
MHz
Sidelobe gain
Alu-tape antenna (7,1m) in dB@deg.
Sidelobe gain
Cu-tape antenna (7,5m) in dB@deg.
1,80,03@240,07@24
3,70,16@230,18@23
7,10,24@210,25@21
10,140,81@190,82@19
14,21,15@141,19@14
18,11,39@121,57@12
21,31,87@631,55@30 & 10
24,93,54@263,85@25 & 10
28,54,63@224,69@21


It reveals that 15m is not well performing now with a very high angle of radiation. And indeed it is not doing a good job on 15m although I still make contacts on the band, even DX. But with the new design that would be a lot better.

Comparisation between old design and new design field plot
The copper tape is a new thing. Unfortenately it isn't as cheap as aluminium tape. But though I hope it is performing slightly better. Theoretically it should. Not shure what I'll do with the coppertape yet, I experimented to see if a wire could be soldered to the tape. As seen on the picture that seems not a problem at all. However I think I will tape a copper wire at the coppertape in case the tape will break.
It would be better to solder the wire to the tape. But I don't like to solder 7,5m of wire, it would not ad anything only costs a lot of solder.

5 comments:

  1. Hallo Bas, ik ben benieuwd naar je experimenten. succes, 73 Paul PC4T

    ReplyDelete
    Replies
    1. Inmiddels al ver gevorderd. Ik heb foto's, ik heb het verhaal. Alleen nog geen tijd gehad om het samen te voegen. Kan wel verklappen dat de nieuwe vertical het prima doet. 73, Bas

      Delete
  2. Hallo Bas, zo te zien aan je log rechtsboven doet de nieuwe vertical het erg goed richting Zuidamerika en China. Nou dat is geweldig.
    73 Hans, PE1BVQ

    ReplyDelete
    Replies
    1. Hallo Hans, inderdaad ziet het er goed uit. 10m was gisteren verlaten. Maar zelfs daar kon er nog met zeer zwakke signalen gewerkt worden. Condities helpen ook mee natuurlijk. Als ik tijd heb wil ik andere banden ook nog proberen. Een verhaaltje komt er aan. 73, Bas

      Delete

Thanks for your comment. Bedankt voor je reactie. 73, Bas