Does anyone know what the theory behind these antennas is? all i can seem to see is that the radiator is about a full wave – but what about the. Ok, I know I just posted about Moxon antennas, but doing an image search for moxon antennas led me to the CJU antenna. Amateur Radio,Projects,Antenna Designs, Double Quad Beam,2m & 70cm SSB, Ham Satellites I found the 70cm CJU or IO works well on mhz as well.
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CJU 70cm Directional Orientation
Who is online Users browsing this forum: The following frequencies are exclusively for satellite use: This antenna has a bit less gain than the seven elements Arrow antenna because the Antebna antenna is equivalent to a four elements yagui antenna, but we have experienced that it has enough gain to receive the satellites comfortably.
Vul je gegevens in of klik op een icoon om in te loggen. We were s earching around for some stuff suitable but we did not find it, so I talked about it with my father EA4ABV who apart from ham he enjoys raising canaries, and told me wait, perhaps the plastic stick where the canaries perch on in the canary jails has this measurement.
anteenna A bit slow at loading,but persevere. Well, in a couple of afternoons I have just built the prototype, now Pedro EB4DKA had to test it because he is the expert at working in portable conditions.
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Then we were looking antfnna and we analyzed the antennas we usually use to receive UHF signal with enough gain. So we became again searching for a linear polarized UHF yagui, because if we work with a hand held antenna, to install a circular polarized one is a nonsense.
CJU or IOIO Antenna for 70cm | PDØG HamRadio
Daarna een RF verzwakker tussen gezet om wat db-tjes te killen. Het maken van de CJU. Register for a free QRZ account.
Does anyone know what the theory behind these antennas is? We can not expect to hear it clearly, we will have to make an effort to antennaa the modulation up from the noise and we must add that we have to change the polarization and the frequency to face to the Doppler effect.
When somebody uses these frequencies because they do not know the rules we must try to explain them, we must always be polite. Discuss construction and design in here. Do you enjoy making your own equipment or antennas? Webmaster, add a Remote rating The CJU Antenna – related links We thought you might also be interested in these additional web sites, selected from the same category: Would it also work if the radiator was mounted at right angles to the reflector.
So this is the option which fit to our necessities, we gave up searching and became to work. Then we only had a way, to improve the antenna. Anyway, I built the CJU 70cm antenna and was surprised about something.
Various people say that it has the gain of a 4 element beam,even that can vary from design to design. Polarity can be “adjusted” merely by twisting it.
Maybe a cut and see approach. We must search for a directional antenna with similar gain but with a less length boom. Voor meer informatie, onder andere over cookiebeheer, bekijk je: If not,it is obvious it is the dimensions,or ratio of the sides of the radiating element that give it the gain.
Have you experimented with it on local repeater systems? It is a pity to listen to hams, specially from our country, through the satellites. How all of us know the difficult thing is to receive the downlink because the satellites usually transmit with power out between 50mWatts and mWatts with changing polarization and up to Km far away.
But from the articles and videos I have seen, it is a directional, “point at your target” antenna. If it’s still not acceptable, I’ll find a way to get to the local ham store only open during office hours to get a better coax. You need to learn some skills to work satellites so at the beginning you must listening several passes before you push the PTT. Regarding AO51,on the other topic,I have put a few pass times.
I would be happy just to know what the dbd gain was,I cannot even find that out. This kind of behaviour interferes with satellite communications making them more difficult that they are. I know exactly how you feel regarding the dimensions etc. Amtenna bet you wished that I had not brought the aerial to your attention. I’ll xntenna it first to see how that works.
When an antenna is attached to an HT, the feed line or no exist or it is too short that we do not have feed line losses, so to set a preamplifier is a nonsense. I think that with this tool attached to an HT in your left hand and with the microphone of your mobile station in your right hand you will make satellite contacts successfully. Je reageert onder je Facebook account. But in our minds were the same question, Would it work? The scale is 1 – 10, with 1 being poor and 10 being excellent.
It might be just a design where you leave it as it is. But still using the same dimensions and spacing atenna the reflector. This antenba of working have given us a impressive outcome even with SSB LEO satellites, but I will not speak about them to clarify the article.
The CJU Antenna
Also a couple of sites for pass times. At this moment im definitely pleased with this antenna so far. It sounds like a problem with the reflector size or spacing We antennx never send a CQ, it is enough to say our call sign or to call another station we have listened before.