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Author Topic: Need advice choosing 2 meter EME antenna please!  (Read 369 times)

W4IJ

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Need advice choosing 2 meter EME antenna please!
« on: March 24, 2021, 10:04:58 AM »

I am considering either the M2 2M9SSB/FM or the 2M12.  The prices are almost the same.  The gain of the 2M9 is listed as 14.1 vs. 14.9 for the 2M12.    The boom length of the 2M9 is 14.5 ft vs. a whopping 19.5 for the 2M12.  The weight of the 2M9 is 5 lbs. vs. 8 lbs. for the 2M12.

I plan to use one of my Majestic view camera tripods (load rating of 25 lbs) for mounting the antenna.  I do not at this time plan on adding a rotator, although the tripod would certainly hold a G5500. 

Since I will be close to ground level, I am concerned that the 12 element beam will limit my elevation.  Being inexperienced in EME, I would appreciate your opinions of the "real world" gain advantage of the 12 element vs. the "manageability" of the 9 element.  I do have the capability of running 500-600 watts.

Thanks so much in advance for your help.  I'm looking forward to experiencing a new aspect of our hobby.  At 74, I figure I better learn new things while I still can!

73, Steve
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W9FIB

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Re: Need advice choosing 2 meter EME antenna please!
« Reply #1 on: March 24, 2021, 03:24:00 PM »

The short time I played with 2M EME, I had 8 - 9 element boomer antennas on an H frame on about 20' of tower. I had both a direction and elevation rotors. I was able to hear my echos on CW with a borrowed Henry QRO amp. I only had 160 watts myself and never established a contact.

However with the digital modes today, contacts are much easier to establish and complete. Along with internet spotting and emails to coordinate contacts.

If I just had a choice of those 2 antennas, I would use the 2M12. Also the lowest loss feed line you can afford. Every fraction of a dB becomes critical.

I had to tear it down due to a move, and sold most of the parts. I never got back into it again.
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73, Stan
Travelling the world one signal at a time.

KB1GMX

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Re: Need advice choosing 2 meter EME antenna please!
« Reply #2 on: March 29, 2021, 08:04:04 AM »

Everyone I know that does EME is running more power and at least
two of the biggest antennas they can get.  Or more!

Why?   The path loss for EME on a good day (straight up) will be around
250DB [can be worse!] so every watt you aim at the moon is critical
and the beam width you radiate with needs to be narrow so all of
you power hits the moon and does not fly by and around the edges
of it.

I tried it with a 11 element long boom with mast mounted AAR prreamp
heard a few (their end was 4 antenna box of 18 elements each and
1500W) they never heard me.  The 11 element was marginal on RX
and 200W did do it even with FT8.  If I go back to that it will be a
4 antenna box with not less than 16 elements each fed with
LMR600 and at least KW out.

You always need more antenna for that. 

Allison

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KM1H

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Re: Need advice choosing 2 meter EME antenna please!
« Reply #3 on: March 30, 2021, 01:32:34 PM »

A 100W and a 8 el yagi has made many EME contacts as reported in the ham rags. Its all about timing and pick the best times to do it (join an EME group)  Dont point at a noisy part of the sky. There are several huge stations around the world that are constantly monitoring and glad to work a new call.

Use little to no elevation wait until the moon is heading to the horizon and take advantage of the ground reflection gain.

Ive heard my echos many times at the horizon on 50, 144, 222, and 432 running 1200, 1500, 1500, 400W respectively and 8 el, pair of CC 4218XL's, modified single long boom CC 220 (A resized 3219) on 222, and stacked HB 24' booms on 432 also respectively.  Except for 6 they were well out of the noise and 6 was Q5 copy. All bands had very low home brew NF preamps confirmed at a yearly VHF/UHF conference.

Ive never made an EME contact and just ping the moon a few times a year to confirm station performance. Ive had several QRZs in return but never took the time or interest to learn the protocol as EME simply didnt interest me....neither does FT8 on MF/HF or whatever is used on EME these days.

Carl
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W1VT

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Re: Need advice choosing 2 meter EME antenna please!
« Reply #4 on: March 30, 2021, 04:01:30 PM »

I made two QSOs in the ARRL EME contest using a 160W brick and a CC 13B2 antenna. 
I had a rotator and a short mast on top of my Saturn Sedan, allowing me to drive around to optimize the signal.
I was at the summit of Mt Equinox and had excellent ground gain. 
I heard a bunch of Europeans but didn't wear myself out trying to work anyone.  I used that window for practice.
I exchanged paper cards with W5UN.

Zak W1VT
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