[amsat-bb] Re: Ideal AMSAT FM Transponder

Trevor . m5aka at yahoo.co.uk
Mon Oct 1 04:07:58 PDT 2012

--- On Sun, 30/9/12, Robert Bruninga <bruninga at usna.edu> wrote:
> With an FM downlink, anyone can receive it with an HT and a
> laptop with PSK-31 software.  And anyone with a 10m PSK-31 uplink
> can transmit to it. 
> The SSB uplink and UHF downlink transponder fits on a
> smaller than 3"x3" circuit board

Sounds great Bob. 

I presume the reason for UHF downlink rather than 145 MHz, with it's lower Doppler shift, is due to other mission constraints ? 

BTW is the uplink in the amateur satellite segment of 10m (29.3-29.5) or down at the bottom of the band ? 

Hopefully IARU / ARRL will be successful in getting an Amateur-satellite allocation at 50 MHz since the CubeSat antenna problem would be easier to address on those frequencies. 

A thought occurs to me. We use Oscar-7 mode B with its input outside the bands allocated to the Amateur-satellite Service. We can use it because various National Societies have negotiated with their Regulator to allow its use by amateurs in their country. I wonder if a similar approach would enable the use of 50 MHz as an uplink band prior to any WRC changes ?

73 Trevor M5AKA

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