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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The free space elevation plots NEC4Win clearly depict the improvement of the new design over the “original” eggbeater. If the SWR is above 1.
It is, basically, just two full wave loops fed in quadrature. At right is an example setup for Field Day use. I suggest a quick continuity test between the shield and center conductor of you coax and phasing lines before you start tearing your hair out. It also uses, optionally, a pair of parasitic reflector elements to focus more of the radiation pattern overhead. Hi Bob, I did some testing with a rtl-sdr. They host 3D print related files for free.
Cut the RG about 2″ 5 cm longer than these measurements and leave 1″ 2. Commercial versions are available from M2 Antennas.
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The loops will be 54 cm wide by Did you check eggbeatrr eggbeater antenna with an antenna analyzer? Not sure where you found the plans, as his original AOL site went away – however I eggbeatwr previously grabbed the pages and Jerry has authorized me to publish them on my server, so here is that link for future reference: This 93 Ohm cable is not as commonly available as RG-8 or F.
The RG will be 45 cm long plus 2.
Last week i also made a few eggbeaters one for MHz and one for MHz. At 15 degrees, they are strong and clear–without a preamp AND with over 50′ of feedline. The phasing lines are made from RG 93 Ohm, see eggbeayer below coaxial cable. For the 2 meter uplink, you may never tell the difference.
I found the use of a preamp necessary. Good luck with the rest of it. Eggbeater Check for a short in your coax and phasing lines, It can happen to the best of us. Anyenna been using Jerry’s design for years, and have built several for friends as well.
The second major distinction is the location of the reflector elements. 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.
As it happens I have a bunch of it I picked up 30 years ago that I have been salvaging the braded copper shield from for grounding straps. Login or register to post comments. In short, you give up very little and theory predicts an almost constant signal level from 15 degrees to directly overhead.
[amsat-bb] Homebrew Up-Dated Eggbeater Antenna
The signals stay strong and pick up about 3-to-6 dB of strength up through 90 eggbeqter. Re check your dimensions, for the 70cm version, my loops are about 76 cm.
Jerry’s notes suggest first checking the SWR with the abtenna loops in parallel, without the phasing line. If you sended an e-mail than your question should appear after an admin has allowed: The TPM improved the coaxial gain of the eggbeater by re-shaping the loop into a square and moving the reflector closer to the driven element. It is recommended reading.
With the reflectors installed, test for SWR. I did some testing with a rtl-sdr. The distance is not so critical and can be adjusted a small amount to get the SWR perfect.
Eggbeater Antenna Tested In Our Anechoic Chamber ( MHz) – Hardware – Libre Space Community
The ring lungs at one end of the phasing line can be shared with the 50 Ohm feedline F or amtenna recommended so that only four ring lungs are required. While I have not attempted to use this antenna for pacsats, I have monitored the signals on FO while in mode JD and found I could copy at S3 or better from horizon to horizon with preamp.
If you use the “original” eggbeater as the starting point, it is easy to describe this improved design, dubbed Eggbeater IIin terms of differences and deviations. I used the plans posted by k50e and am at a loss as to what is causing it. Common 1″ PVC couplings and stainless hardware are used. His prototype design, however, may be difficult for the average back yard mechanic a ham with two left thumbs to reproduce. Ground Based Elevation 35′ Any hints or clear plans would be a help.
For the 70 cm downlink, it could mean the difference between copy and no copy.
I have heard the cable on automobile stereo antennas is RG, so you might want to wntenna your local parts dealer or WalMart to see if a cheap replacement antenna-with-coax is an easy source.
Starting with a square and “playing” with the shape allowed me to find a very good match at Ohms, purely resistive. Hello Joseph, Your antennas gook great! And after that if you still do not have found the problem than post an e-mail message to amsat at amsat-bb. But ko2f said he made an STL for a drill template. The input impedance of the round loops with reflector was close to 90 Ohms–too low. 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.