Re: [amsat-bb] Helix or ao uplink or not?

[K5OE@xxxxxxx]

Brian,

>  Im very new to AO40 and would like to know if a helix 435mhz is good for
>  uplink
>  to AO40 or is it better with a X-yagi if we say the gain is the same on 
both
>  antennas?

A helix is a pretty good transmit antenna because it is easy to build and 
tune and has a wide bandwidth (it is hard to go wrong).  Plus, it is already 
circularly polarized.  I do not care for them as receiving antennas at UHF, 
though, because that wide bandwidth means they pick up a lot of noise.  A comparable 
gain Yagi, although more difficult to build, tune, and get working as 
circularly polarized, acts as a front end band-pass filter for your receiver.  There 
are several satellites using UHF downlinks and many more on the drawing 
boards.  For that reason, I would recommend a Yagi over a helix.  If you plan to use 
it exclusively for AO-40, then my comments don't apply.
73,
Jerry, K5OE
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org