if a crossbeam will still work above 20 amos if it is noticeable and will catch the eye (it has an amlistera),
how come we dont say by a chanukah menorah that even if it 20 amos high one should be yotzei since it is a light in the darkness, and it for sure would catch ones eyes ? ( rashi in shabbos 22a says the reason a menorah cant be 20 amos high is because ones eyes wont be caught by it)
Azarya Coren, United States
Your question led one person in our time to ask Rabbi Asher Weiss if he could place an amaltara (in the form of twinkling electric lights) near a menorah and light it above 20 amos, since in this way it will catch people's attention like a menorah.
Rabbi Weiss responded that we have not found such a concept in any of the poskim and therefore we cannot innovate it ourselves. He added that there are two major distinctions between the amaltara and the menorah:
1) The amaltara is an integral part of the crossbeam and is engraved on it so if people look at it they will notice the crossbeam. However making electric lights below the menorah will not help since one will focus on the electric lights and not on the menorah.
2) By eiruvin what is required is a hecker or something which is noticeable and for that the almatra is enough since it's design makes it noticeable. However the Menorah requires Pirsumei Nisa (recognition of the miracle) and this needs it to be much more visible and if its above 20 amos this is not enough.
The Sfas Emes explains similarly why an amaltra can't work for a Sukka above 20 amos, since there there is a requirement of Lemaan Yed'u and this needs a higher form of recognition than with an Eiruv
Yoel Domb