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RE: This Weekend in Minneapolis: Central States VHF S ociety Meeting



At 11:12 AM 7/27/2006 +1000, Tony Langdon (ATC) wrote:
>
>> I liked the C-C rider concept, but I like the S1/C 
>> transponder proposal as 
>> well.  Recently I purchased a 50W amplifier and PSU for 2.4GHz from 
>> decommissioned MMDS equipment at less than US$100.  With my 2.4GHz 
>> transverter I am half ready.   I haven't seen any equipment as 
>> cheap/available for a 5.65GHz uplink compared to 2.4GHz. 
>
>I thought 2.4 GHz was space --> earth only, so setting up for an uplink
>there would be a waste of time and money.  2.4GHz Tx gear would be for
>terrestrial use only.

Everyone:

As I predicted, there has been a bit of talk in response to the Eagle report.

AO-40 had a 2448 MHz Rx and was tested if I recall.  Not many users had
transmitting equipment for that freq. so I'm guessing it only was an
experiment (maybe for digital modes).  But there is an allocation for
mode-S uplink.

I was excited by the prospect of CC-Rider, since it would be in-band on
5-GHz.  Apparently, the decision is that is too difficult to build so it
will become mode-S/C.  I have a 60w Spectrian Amp but not sure it is
wideband to work at 2448.  I will have to come up with a Tx-convertor and
C-band Rx convertor if I am to work that mode (also remember this is a
digital voice mode).

I am happy that I should be able to use mode-LS on P3E.  If I get
autotune/tracking setup I might try it on AO-51 (doppler change is very
rapid).  I guess I was taken by surprise by the notice that modes US and LS
were abandoned on Eagle.

Regarding whether the design crew has operating stations does not bother
me.  I am one that spends most of my time designing and building and less
in actual operation.  This is the "engineering" part of ham radio.

What is important is that the spacecraft builders in Amsat do not become
disconnected from the operating group, else we may not be building what the
operators are asking for.  Engineering realities cannot be ignored; I
understand that.  Likewise "customer" reality must be addressed in the
design process, or the customer will go away.

The demise of mode-UV (old mode-B) on AO-40 (and the early death of AO-13)
lead to a massive loss of Amsat-NA membership.  That lesson should not be
ignored.  Mode-UV is supported on Eagle (and that will be accepted with
cheers).  My original point was that Amsat had stimulated a whole new group
of mode-US (and mode-LS) operators that likewise expected "their" mode.

At least we have an open forum in the design process so we learn early the
direction the satellite is moving.  This we can decide what is needed for
operation early on.  Kit manufacturers also have longer lead time to
develope special satellite equipment.  At this point I am glad I did not
purchase the $400 mode-X (10,450 MHz) downconvertor for AO-40.

OK, I have unloaded my comments.  Take what you will.

73's,
Ed - KL7UW 
===================================
BP40iq,  Nikiski, AK      http://www.qsl.net/al7eb
Amsat #3212
Modes: V - U - L - S
===================================
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