Building my Eggbeater II Omni low Earth orbit satellite Antennas for 70cm I only had vertical 5/8 ground plane antenna fro 70cm and 2m band. M2 Antennas Eggbeater Satellite Antennas offers exciting new performance characteristics for both fixed and mobile operations and will let you. Constructing an egg beater antenna for working satellites is reasonably straight forward. George Wilenski’s (ON6WG / F5VIF) documentation.
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[amsat-bb] Homebrew Up-Dated Eggbeater Antenna
I have heard the cable on automobile stereo antennas is RG, so you might want to try your local parts dealer or WalMart to see if a cheap replacement antenna-with-coax is an easy source. I am testing it in parallel with a commercially built Eggbeater manufactured by M2 Antenna Systems. I have been working on a uhf eggbeater antenna for about a week and cannot get the thing to tune worth squat.
I cut the antenna elements for The signals on AO are much harder to capture and the horizontal polarization at the horizon is a definite penalty. I got good copy on the bird once it reached about degrees elevation–compared to to degrees on my original eggbeater.
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If you are using another metric perhaps pipe size, most 3d printers allow you to scale a part without too much difficulty. Construction was easy and took about half a day. Since the two rectangle-loops are fed in-quadrature but out of phasethe resultant feedpoint is very close to antennz Ohms with no reactance. To use it, Print the drill guide, scaling it to fit snugly over the plastic pipe you are using to make your antenna. Commercial versions are available from M2 Antennas.
I am currently unable to supply any more surplus cable, but you could contact Dino, K6RIX, to see if he can provide you with a small amount.
The drill guide is pretty simple. This antenna, mounted at 35′ elevation, performed very well for an omni-directional design. For the 2 meter uplink, you may never tell the difference.
For the 70 cm downlink, it could mean the difference between copy and no copy. At right is an example setup for Field Day use.
The reflectors will be cm long and cm distance from the feed point. Nevertheless, how to improve the eggbeater as an omni-directional antenna? This effect makes it a “gain” antenna, but that gain is at the expense of low-elevation reception. There are no plans, everything is done with pen and paper and the drilholes are just measured and pointed on a PVC tube. The input impedance of the round loops with reflector was close to 90 Ohms–too low. Did you check your eggbeater antenna with an antenna analyzer?
Eggbeateg free space elevation plots NEC4Win clearly depict the improvement of the new abtenna over the “original” eggbeater. They host 3D print related files for free. Re check your dimensions, for the antenn version, my loops are about 76 cm.
Eggbeater antenna | ISS Fan Club
Also put a little part of the used plastics inside a microwave oven and if the plastics feel warm than you can not use it for the parts which have to be electrical isolated! If there is any interest, I can probably write up a construction article and provide the STL file for my drill guide.
Eggbeater Check for a short in your coax and phasing lines, It can happen to the best of us. Simply connect the coax center conductor to any two adjacent loop ends and the coax shield to the other two adjacent loop ends.
eggbeatet These dimensions are very precise and will work well with 10 and 12 wire for 70 cm onlybut you may want to make the loops slightly larger and trim the extra length based on your SWR readings.
I would be interested in learning more about this approach. The signals stay strong and pick up about 3-to-6 dB of strength up through 90 degrees. The distance is not so critical and can be adjusted a small amount to get the SWR perfect.
CGerald R. I find these to be very broadbanded and forgiving if your dimensions are even close. It is obviously easier to do this as the build is in progress, but did you check each loop individually?
Hi Bob, I did some testing with a rtl-sdr.
The first distinction is it does not use a round “loop” for the driven elements. They look the part. There are no 3D prints in this construction.
Note that there are 2 marks on the top of the guide. Drilling nice square and correctly aligned holes through a round plastic pipe can be a pain so I designed and printed a simple plastic drilling guide to make this easy. As a matter of fact it won’t tune at all. dggbeater
[amsat-bb] Homebrew Up-Dated Eggbeater Antenna
It is recommended reading. If the SWR is above 1. Remember that 6 dB is gained in reduction of the satellite’s path ahtenna and 3 dB is gained in the improved circularity of the signal as the bird reaches higher elevations.
Eggneater you have a 3d printer and you are using this kind of pipe, it will help you get the holes properly aligned. Login or register to post comments. Any hints or clear plans would be a help. Note the gain is almost the same at 45 degrees, but the new design is 6 dB better at 30 degrees and about 10 dB better at 15 degrees.
But ko2f said he made an STL for a drill template. The antennas are now eggheater to their fixed location and everything has to be reconnected again. Good luck with the rest of it.