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Hi, because I don't know what to do with my free time, I'm a little bit experimenting with antennas, but I want to ask about the tried and tested ham. I have a windmill with dimensions of 41m. length and water supply is at 13.6m. and as we know it at this point it has an impedance of 300ohms and I ask it, it is possible to supply it with ribs and I tune it to tRX with Z-matches? I have the Z-match built according to the newsletter from the special issue on antennas. What do you think of this set? Thank you for your opinions.
Hi, of course, I know about this possibility, I was just wondering if it would work in such a set as I described above…
And so I came to the answer, that I probably can't use the ladder, because the windmill is more of a band antenna and the ladder would always be tuned to only one band, or if I used an untuned length, but it would be repeated on one of the frequency so that impedance would always be those 300 ohm at least that's how I understood it… so it turns out that I can only get the balun there 6:1 and a 50 ohm coax or single wire lead and tune it.
The antenna is in a different environment (height, surrounding buildings, subsoil) behaves differently, sometimes the changes are very significant. The variant with a balun like FD-4 is proven. Not every band will be ideal, but even the worst case will be decent.
See: http://www.radio-foto.net/radio/windom.php
The balun must be made well – on a suitable material, suitable wire and the whole well secured against the ingress of moisture.
Suitable antennas are offered by Jirka http://www.ok5im.com/
If you have a place and especially a height on the ladder, so get a G5RV. See otherwise http://users.erols.com/k3mt/windom/windom.htm , you have it there with the balun.
G5RV you have also described this http://www.packetradio.com/windom.htmThe G5RV antenna has 300ohm in place, so you can use a 300ohm double line. But you still have to transform the impedance with a balun to 50ohm. If you do it at the place of the power supply, or it's up to you at the transceiver and this applies to all bands on which the antenna runs!!!
Hi thanks for the advice.. I am interested in the G5RV, so the long ladder can be arbitrary when I connect it to the transmatch?? because I divided the instructions where the length of the ladder was 10.36 m. and then there was a coax connected. This is how it was powered due to impedance matching? so I don't have to use transmatch?
The G5RV is not a bad antenna. However, Luis originally conceived it as a profitable antenna for the 20m band and it was later discovered, that it can be used in other zones.
The variant with a ranking up to the shack is better.
The impedance of the antenna is strongly dependent on the environment and there is very little hope, that impedance matching will satisfy all bands. In addition, combining a balanced and unbalanced power supply will cause reverse current flow and possibly TVI problems..
Which antenna depends mainly on the spatial possibilities and requirements for the type of connection. For example 1/4 vertical at 80m is an excellent DX antenna, but for close range connections the horizontal dipole or Inv.V is better.
Lukáš, would be able to specify antenna requirements and space options?
Hi, I care about an antenna that I could use from 80m. do 20 popripade az do 10m. as far as space is concerned, I have a free area of approx. 45 m. between two panels, I myself live on top of one panel. I have selected some antennas only now I do not know the best option. he thought about these antennas: coaxial powered windmill over the balun, dipole powered by a rib, W3DZZ, G5RV, next maybe I would get on the roof of INN-V and I could also think about delta loope… Which of these antennas would you recommend in the future? If possible, it is possible to work with the 80m band CW and SSB operation.
The required bandwidth at 80m would be achieved by a dipole antenna only with a large conductor diameter (a few meters). This is usually done across the board, or even better by the spatial location of several conductors. E.g.:
http://pagesperso-orange.fr/f5rrs/images/ya-30.jpgWindomka powered with a ladder can be tuned everywhere – if an ATU is suitable.
G5RV construction with ladder transition – coax will not be good. For the narrow segment, e.g.. len CW, where the higher frequencies are times the lower band, it could be tuned, but for a greater retuning I would not try.
W3DZZ is walkable, but the bandwidth at 80m is smaller. If quality traps are made, walks well.
The possibility of parallel dipoles is still offered, e.g.:
http://www.hamuniverse.com/multidipole.htmlI would choose either FD-4, because it is a simple antenna, Proven for years as a good antenna, comes out a short lead coax cable, but at a disadvantage, that the bandwidth will be less, or Ladder powered by a ladder, which requires a little more effort (ladder, ATU and frequency change tuning), but the rewards will be able to tune in anywhere.
Hi, thank you for the advice, I'll probably try the FD-4 here, or if I manage to make a ladder, I'll try to power it up as I wrote above.…
Hi,
It would be my pleasure, if the councils are helpful. Maybe I'll see a QSO with you, hi. The toroid for the FD-4 balun can be obtained from Martin Karasz, or a balun or the whole antenna, for example at Jirka OK5IM. A suitable toroid seldom rolls in a drawer… and bad material would adversely affect the characteristics of the antenna.
Z-mach is an excellent matching circuit. Powering the ladder is a bit problematic, whereas it needs to be made of very high quality due to bending (from the center of the antenna down, then to the side and up to the shack). It would be easy in the case of a shack on the lower floor.
The decision about the antenna itself is usually made by a radio amateur based on feeling. For example, I have a bad experience with HB9CV and I prefer antennas with higher impedance, ideal with impedance 50 ohm at the power point (1/4 vertical, OWA yagi, quad). But they certainly are radio amateurs, who have the opposite experience.
Hi, whether there is a toroid we have in the radio club and I have something at home, so I'll try to wind several baluns and then we will measure the most suitable. and yes, as you write with that ladder, I would probably have quite a problem getting it into the apartment, maybe more than with the production itself…
as for my favorite antennas, I prefer wire antennas like LW or then dipolol also had vertical varnishes, but unfortunately on the roof I could not stretch full counterweights and not anchor it well…
As for the common QSO, we may meet somewhere at 80m. grazing in the SSB sector, I make connections there under the club brand OM3KMK, so far only the answers to the stations that call the call, but I'm also going to train calling the call…
Hi Lukas,
I see you're a panel ham (like me) so I've dealt with the same worries and I'm actually dealing with them so far…
I would also recommend FD4, best with ribs, you can fine-tune it, but even with a balun, it will be good. Balun buy better done because trying which souvenir toroid will be good does not seem to me as very practical.
Imagine putting your new FD4 maybe 5 times up and down and changing the balun for a big “interesting” neighbors and residents of the surrounding apartment buildings – you will make a lot of problems because every Inet crash, The TV and the broken TV next door will fall on your head. I speak from my own experience! There is one work – the antennas stand on the settlement (I really don't start) in the dark and when it's empty. Rano ten drot ani nezbadaju.
Check out my site for inspiration http://www.qsl.net/om3cug where you will see how I have made wire antennas for 80 / 160m and especially how I have built the vertical HF9V on the roof and anchored without any problems. FD4 is going well 80 up to 10m but when you place a vertical on the roof, you will first fall off the flaps from the eyes and then the sledge because you will notice what a huge difference on the upper bands compared to the wire. I only go with QRP 5W and see on my website what can be done with such an antenna set.
I wish you a lot of luck in installing the antennas, 73 Igor OM3CUG
