[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Mode-B vs Mode-J




This is why I want L Band (1.2ghz) to be the uplink and U Band (70cm) to be 
the downlink. It will help allievate the aligator problem. People will not 
spend the money to have big amps on L band and will most probably have 
better "ears" than "mouth" so the situation will be better for everyone. 
LEILA will not be going off all the time. If you can hear your downlink on 
the sat, then you can talk to it without causing everyone problems. We need 
to advance the hobby (work in L band) and have something new to work and 
not just put up old technology (Mode B). If we must put up old technology 
it should be strickly a second level backup capability in case the primary 
or secondary systems fail. We should not be encouraging people to use Mode 
B. But let them have it ... a little, as power budget permits, if we must.

W4SCO


>Thus, the typical Mode-J downlink performance is 20+ dB worse than the
>uplink.  Thus you need beam antennas, skill, and good (not deaf) equipment
>to hear it.  That is why you hear so many LID's calling CQ who cant hear
>it.
>
>Flip all these around for mode B and instead of having a 20+ dB inbalance
>in the uplink and downlink, you end up with a pretty well balanced system
>for the OMNI antenna user.  Everyone can hear the 1W satellite down link
>10 dB better, and you wont hear so many LID's because now they have to
>take a little more care on their uplink settings to be heard.
>
>Mode-B is really quite a nice way to go.



----
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



AMSAT Top AMSAT Home