It might take a fair bit of work to get that usable for 23cm satellite uplinks, which are at 1260-1270 MHz. From the FM satellite frequency list on the AMSAT web site, you would want to prepare for uplinks around 1267 MHz (AO-92, Fox-1Cliff) and 1263 MHz (FUNcube payload on ESEO). Since you said that unit was supposed to output across a 4 MHz range, it might be possible to adjust it so that the 4 MHz range is 1263-1267 MHz instead of 1296-1300 MHz. Looks like someone may have been trying that already, given that tag showing 1291.976 MHz as an output frequency. You could use an SDRplay SDR (or other receiver covering that band) to see where the output is for that device. Set a wide range in the SDR software, and transmit at low power. Do you have an antenna for the 1.2 GHz band? I don't know how far away from 432 MHz you can transmit, to bring the output frequency down to 1263 or 1267 MHz. I'd guess you would still need to make adjustments to get the output down to the satellite subband, instead of the weak-signal subband at the high end of the band. It might be useful to visit other forums/mailing lists related to EME or general weak-signal activity with your questions about this, as well as the satellite-related forums/lists. 73!