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



----- Original Message -----
From: "Edward R. Cole" <al7eb@acsalaska.net>
To: <amsat-bb@AMSAT.Org>
Sent: Thursday, July 27, 2006 8:59 AM
Subject: RE: [amsat-bb] This Weekend in Minneapolis: Central States VHF S
ociety Meeting

> 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.

Hi Ed, KL7UW

Along with a 2446 MHz Rx never tested in orbit AO40 had also a
2400-2402 MHz Rx and it was succesfully tested only one's by N1JEZ,
G3WDG and i8CVS day 02/23/03 for a S1/K test and my uplink power was
about 10 watt in to a 1.2 meter disc with a 3 turn helix feed the same disc
used for the 2400 MHz downlink.

> 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).

P3E will use a S band downlink from 2400.250 to 2401.000 MHz including
everyting i.e. analog passband + Rudak + beacons so why don't use 2401.000
to 2402.000  MHz at least to fill the so called "sever" for the uplink mode
S/C on EAGLE ?
Using 2448 MHz  for the uplink mode S/C on EAGLE it make the life difficult
to those who like you Ed, me and several others have already a 2400-2402 MHz
transverter with a 2400 MHz power amplifier antenna mounted never currently
used for AO40

In addition P3E will use a C band uplink on 5668.300 MHz +/- 25 kHz linear
Now if EAGLE will use a mode S/C with a downlink on C band why do not
cover the uplink of P3E and the downlink of EAGLE in the same C band
5668.300 to 5668.800 MHz or wider originally planned for AO40 ?
In this case it would be possible to build a single 5668.000 to 5670.000 MHz
transverter with a preamplifier and a power amplifier antenna mounted to
cover with the same disc the uplink C band for P3E and the C band downlink
for EAGLE

Many of us in Europe are already equipped for the never used uplink designed
for AO40 covering from 5668.300 to 5668.800 MHz

> I am happy that I should be able to use mode-LS on P3E.

For P3E AMSAT-DL has two L band options for the uplink all including
analog passband and Rudak

1268.600 to 1268.925 MHz Uplink1 (L1)

If using L1 we have problems of interference with the Galileo System
than we can switch to

1263.225 to 1263.550 MHz Uplink2 (L2) Galileo Alternative
as Peter DB2OS explained in his letter "info on P3E" sent to the net
on 16 april 2006

" The 2nd  L band uplink was allocated exactly to the first minimum of
spectral density of GALILEO E6-A which is 1263,520 MHz (frequency
of the E6-A carrier is 1268,520 MHz and chip rate 5 MHz).
The 2nd or secondary L2 Gallileo alternative uplink will only be chosen
if the primary L1 uplink can not be used..   it's just a switch in the
transponder "

For the above reason I already got a XTAL just in case for the new LO of
my transmit converter wich is antenna mounted.
93.16666667 MHz x 12 = 1118 MHz (LO) + 145 (IF) = 1263.000 MHz

> 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.

In Italy there are many including IW4DVZ, IZ1ERR, IW1DTU with modern
equipments using AO-51 in mode US and  LS and they will be very concerned
with EAGLE but if P3E in 2008 will be succesfull using the planned
frequencies for the S band and the L band  I am sure that EAGLE will be
forced to revise the actual position.

On the other side I dont think realistic that all EME stations operating in
1296 MHz and all satellite stations using the L band will be obliged  to go
QRT because of the Galileo Positioning System .
Read please.

http://www.southgatearc.org/articles/galileo.htm

> 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.

I agree with you because I  have invested a lot of time and money to build
equipments actually becaming scrap on the roof waiting for years without
hope to be used again from a previous satellite to the next one.

> 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.

It is important that spacecraft builders in AMSAT-NA and AMSAT-DL
do not become disconnected.

As far I know AMSAT-DL did the maximum effort to designe P3E with
the targed to use again the most part of frequencies and equipments that
we already have in hand planned for AO40

> 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.

Actually if you like to have a good CW or SSB QSO in mode UV you have
only the old OSCAR-7 or  the indian VO-52...........HI ! and if you prefere
mode VU you only have FO-29 wich is fine because on day 27 july I got a
nice SSB QSO with W1FC

> 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

Mode-U/V will be supported by P3E as well so that we are happy on this
respect.

> of mode-US (and mode-LS) operators that likewise expected "their" mode.

Ed........don't worry about mode-US and mode-LS because they will be
supported by P3E in 2008

> 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.

In my experience it is best to "prepare for the future" only when the
satellite is fully operational in orbit at "present".

> Kit manufacturers also have longer lead time to develope special satellite
> equipment.

Kit manufacturers do not exist anymore and only manufacturers of modern
and costly all mode equipments are preparing their new specialty for the
future.

> At this point I am glad I did not
> purchase the $400 mode-X (10,450 MHz) downconvertor for AO-40.

Unfortunately I have built a downconverter for AO40 by my self covering the
planned 10450 to 10452 MHz band but actually I can only use it with a 60 cm
disc for sun noise measurements (about 4 dB of sun noise with the actual
average of 75 sfu )

> OK, I have unloaded my comments.  Take what you will.
> 73's,
> Ed - KL7UW

All said  about your concern my best

73" de

i8CVS Domenico
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