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Re: Microwave IF's for working AO-40 (was: Link budgets??)



My reply to Jerry was assuming one had an existing Mode UV or VU station.
Of course other IF frequencies such as 1296, 50, or 28 may be chosen.  

It really comes down to two things:
1.  What modes will be activated.
2.  What equipment do you have to use as an IF.
There is no "right" answer here!  This is where you create your unique
station!

I believe you will find that 144 or 432 will be the standard IF's for
commercially made microwave gear.  BTW my 24GHz up/down conv. uses a 10 GHz
LO {the convertors harmonically double the LO} and a 3756 IF.

I have the DEM new version 1296/144 xvtr and it is not dual-freq for 1269.
DEM will be making a 1269/144 Tx convertor for P3D [no Rx].  It remains to
be seen if a second 1269 LO will be made for the "new" 1296 xvtr.

I have the FT-847 and just programmed a satellite split for 50/145 so you
can do that if desired.  Apparently any two bands on the FT-847 can be used
in SAT-mode.  If you need a 50/144 xvtr look at Tentec's.  I'm not sure DEM
is planning for that freq. split.

I have DEM's 10368/144 xvtr and my understanding is that DEM's P3D x-band
convertor will be 10451/144.  If I remember correctly Kuhne makes a
10451/432 conv.

Don't forget there are two L-band and two s-band uplinks, so the choices
get worse if you want to have it all.  {I plan to have L1-Tx and S1 & S2
-Rx; no S-Tx or C-Tx; K-Rx maybe?}

Coming back to the issue of modes, I suspect that even though some band
combinations are possible, they will not likely be activated {for instance
15m to 3cm}.  I think it safe to bet that certain modes will become
"standard".  {my guess} Possibly: UV, US, LS, LX, SX, CX, ...and?  There
are several reasons that this is likely:
1.  Antenna constraints: dual band dish feeds; tracking accuracy; isolation
of Tx and Rx. 
2.  Equipment constraints:  we already talked about this.
3.  Spacecraft constraints or considerations: some stuff may not work; some
combos not a good choice.
4.  Operator preference:  this will have the greatest influence.

Fortunately there is sufficient time for these issues to be "hashed" and
equipment built/bought!

Ed
Re: Using psk31/DATA port on the FT-847 on 2m and 70cm:  the book mentions
setting DATA power levels on 2m and 70cm, so that would indicate to me that
this port is usable there {haven't tried it}. 


>From: "John P. Toscano" <tosca005@tc.umn.edu>

>Jerry Pixton (W6IHG) wrote:
>
>> Any thoughts on S Band Converter output frequency? Choices seem to be
>> 2 meters or 70 cm. If there really is some problem with 70 cm
>> transmitter then 70cm might be the uplink band and therefore the
>> Converter should downlink from 13cm to 2 meters??
>
>Current L-band and S-band transverters from Down East Microwave
>  http://www.downeastmicrowave.com
>use a 2 meter IF (144-148 MHz).  They also sell an additional adapter
>board that will convert any of their 2 meter IF transverters to a 10
>meter IF.  So my initial thought was to strap the two transverters to
>the crossboom of my antenna array (once I put it up with the elevation
>rotor next Spring), and then add 2 pairs of coaxial relays so that one
>transverter comes down to the shack "direct" on 2 meters and the other
>one comes down through the extra board on 10 meters.  That way, any
>combination of any pair of valid uplink and downlink modes, from HF
>through S-band would be possible.  (I'll be ecstatic to get L and S
>going, the "really micro" microwaves can come later!)
>
>If you don't like the idea of coax relays to pick an IF, then another
>solution that comes to mind would be to see if the 2 Meter to 10 Meter
>IF converter could be modified to convert 2 Meters to 6 Meters instead
>(or see if Down East was interested in making a properly designed
>version of such.)  At least for those of us with a Yaesu FT-847, one
>could put the L-band uplink on 6M which is not a satellite band, put
>the S-band uplink/downlink on 10M, and the only combination that
>would be unattainable is HF up and S-band down, a small loss I think.
>
>Before you all pull out the flamethrowers, let me say that I *THINK*
>that the FT-847 allows you to use 6M as one of the bands when in
>satellite mode, though I keep forgetting to test this (and the radio
>is 17 miles away from me as I write this). I seem to remember that
>the wording in the user's manual says something like "you can pick
>any two bands for uplink/downlink that are associated with a
>different antenna connector on the back of the radio", and those four
>connectors are HF, 6M, 2M, and 70cm.
>
>Of course, Down East has wisely not finalized the design of their
>Oscar-type S-band and L-band transverters, so they may have plans to
>use a different IF also.  (Actually, the 23cm transverters they are
>selling now, which are an upgrade from the model I use, have dual
>sub-band capability, i.e. 1269 satellite and 1296 terrestrial
>capability right now.)  But now that the bird is in orbit, we can
>expect to see them start coming out with the new products.
>
>And, of course, there are other products out there too!  SSB
>Electronics is one that comes to mind.
>  http://www.ssbusa.com
> 
>> Waiting and preparing.
>
>Same here!
>
>John (KBØZEV)
>
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al7eb@amsat.org - BP40iq
*************************************************************************
HF-50-144-432-1296-2400-10,368 MHz
Antennas: 4xM2-XP20, M2-436CP42, 23LY45, 5m & 2.5m dishes
cw, ssb, fm, psk31...APRS soon
Satellite:  analog modes  
eme:  144*-1296*-10,368*...*not QRV yet
microwave beacon:  10 GHz planned
Amateur radio astronomy & SETI:  1420-4000-10,370
*************************************************************************
ARRL asst section mgr - Kenai Peninsula Alaska
MooseHorn ARC - president
Anchorage ARC - life member
ARES - member
SARA - member
SETI League - vol. coord for Alaska
AMSAT - vol. coord, Alaska
*************************************************************************
Other interests:  Sled dogs, history

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