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Antenna suggestion
Sirs:
I am a programmer and electrician, but not a radio person! I am sending an experimental balloon to over 100,000 ft. I have purchased two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of 1000 m.a., which states it will transmit and receive up to 20 miles line of sight. I do realize that this is probably under ideal circumstances and will not likely be the case when I actually deploy. I would be interested in purchasing some antennas which would somehow increase the range. What sort of characteristics make up a good antenna for what I want to do? It is possible that someone could find me one that would work with my project? Also, anything you might contribute concerning radio transmission would be very much appreciated. Money is no object for this experiment, so any ideas you have are very much welcome. Thanks, Brett |
Antenna suggestion
Money is no object for this experiment, so any ideas you have are
very much welcome. Thanks, Brett ====================================== Dear Brett, Just send me $800,000 US dollars and I will become your technical adviser for life. Of course, I shall need time-off to spend it. ---- Reg. |
Antenna suggestion
Is that on Antenna/Radio needs only?
:-) Reg Edwards wrote: Money is no object for this experiment, so any ideas you have are very much welcome. Thanks, Brett ====================================== Dear Brett, Just send me $800,000 US dollars and I will become your technical adviser for life. Of course, I shall need time-off to spend it. ---- Reg. |
Antenna suggestion
wrote in message oups.com... Sirs: I am a programmer and electrician, but not a radio person! I am sending an experimental balloon to over 100,000 ft. I have purchased two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of 1000 m.a., which states it will transmit and receive up to 20 miles line of sight. I do realize that this is probably under ideal circumstances and will not likely be the case when I actually deploy. I would be interested in purchasing some antennas which would somehow increase the range. What sort of characteristics make up a good antenna for what I want to do? It is possible that someone could find me one that would work with my project? Also, anything you might contribute concerning radio transmission would be very much appreciated. Money is no object for this experiment, so any ideas you have are very much welcome. Thanks, Brett Hi Brett . Is it possible that your radio power level is 1,000 m.w. rather than 1000 m.a.? I think this 'antenna' problem can be easily/inexpensively solved. if the location of the balloon is known. Jerry |
Antenna suggestion
wrote in message oups.com... Sirs: I am a programmer and electrician, but not a radio person! I am sending an experimental balloon to over 100,000 ft. I have purchased two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of 1000 m.a., which states it will transmit and receive up to 20 miles line of sight. I do realize that this is probably under ideal circumstances and will not likely be the case when I actually deploy. I would be interested in purchasing some antennas which would somehow increase the range. What sort of characteristics make up a good antenna for what I want to do? It is possible that someone could find me one that would work with my project? Also, anything you might contribute concerning radio transmission would be very much appreciated. Money is no object for this experiment, so any ideas you have are very much welcome. Just about any antenna will work . I would look into a 1/4 wave antenna mounted upside down so it is pointed down for the balloon. I hope you ment 1,000 mw, or one watt of power for the transmitter. I have heard the hams in the space shuttle and space station with a 5/8 wavelength on my car. They only run a few watts and are over 100 miles up. Also talked with an airplane at 40,000 feet that was over 150 miles away. I was using a 10 watt radio and a small beam. He was using a handy talkey with maybe 5 watts inside the plane. Unless you are under a bunch of trees , there is not much beter conditions than to be line of sight. While it will probably be too small to see without a telescope, as long as the balloon is in sight almost anything will work. |
Antenna suggestion
On Fri, 28 Jul 2006 21:20:43 GMT, "Ralph Mowery"
wrote: wrote in message roups.com... Sirs: I am a programmer and electrician, but not a radio person! I am sending an experimental balloon to over 100,000 ft. I have purchased two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of 1000 m.a., which states it will transmit and receive up to 20 miles line of sight. I do realize that this is probably under ideal circumstances and will not likely be the case when I actually deploy. I would be interested in purchasing some antennas which would somehow increase the range. What sort of characteristics make up a good antenna for what I want to do? It is possible that someone could find me one that would work with my project? Also, anything you might contribute concerning radio transmission would be very much appreciated. Money is no object for this experiment, so any ideas you have are very much welcome. Just about any antenna will work . I would look into a 1/4 wave antenna mounted upside down so it is pointed down for the balloon. I hope you ment So that would have its pattern null pointed down at the earth? Not to imply that the balloon would necessarily be directly above the observer(s), but if and when it was at the zenith, it would be relatively hard to hear. The OP hasn't told us the elevation angles of the locations of the balloon in flight, how fast it is likely to spin, data rate or equivalent (eg is this intended to send images back?), etc... they are all relevant to commenting on suitability of the 1000mA??? radio, and the type of antennas for the balloon and ground station(s). Owen For an amateur balloon project, see http://members.optusnet.com.au/~phil...oonlaunch1.htm .. -- |
Antenna suggestion
On Fri, 28 Jul 2006 22:29:51 GMT, Owen Duffy wrote:
sending an experimental balloon to over 100,000 ft. I have purchased two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of 1000 m.a., which states it will transmit and receive up to 20 miles line of sight. I do realize that this is probably under ideal I did mean to comment on the temperature spec for the radio. The temperature in the troposhere can be as low at -50 to -75 deg C, will the radio get cold enough in transit to fail (eg battery failure, condensation etc). Owen -- |
Antenna suggestion
At an altitude of 100,000 feet 1000 mw [1 watt] should reach to the radio
horizon of about 300 miles assuming a good receiver on the far end of the range. A vertically polarized 1/2 wavelength antenna should work fine. At least it would be my starting point. Second option would be an inverted [upside down] 1/4 wavelength ground plane. Either antenna is not expensive. What information is to be transmitted? If you are looking for moderate speed telemetry then a path loss versus error rate study needs to be done. If data is being transmitted a gain antenna may be required at the receiver. Gain antennas are not expensive and the antenna needs to be pointed at and follow the balloon's flight path. /s/ DD wrote: Sirs: I am a programmer and electrician, but not a radio person! I am sending an experimental balloon to over 100,000 ft. I have purchased two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of 1000 m.a., which states it will transmit and receive up to 20 miles line of sight. I do realize that this is probably under ideal circumstances and will not likely be the case when I actually deploy. I would be interested in purchasing some antennas which would somehow increase the range. What sort of characteristics make up a good antenna for what I want to do? It is possible that someone could find me one that would work with my project? Also, anything you might contribute concerning radio transmission would be very much appreciated. Money is no object for this experiment, so any ideas you have are very much welcome. Thanks, Brett |
Antenna suggestion
Owen Duffy wrote:
On Fri, 28 Jul 2006 22:29:51 GMT, Owen Duffy wrote: sending an experimental balloon to over 100,000 ft. I have purchased two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of 1000 m.a., which states it will transmit and receive up to 20 miles line of sight. I do realize that this is probably under ideal I did mean to comment on the temperature spec for the radio. The temperature in the troposhere can be as low at -50 to -75 deg C, will the radio get cold enough in transit to fail (eg battery failure, condensation etc). Owen -- YEP! You have to account for loss of battery power, loss of gain in the semiconductors, etc. Or, provide a stable thermal environment. |
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