BATC Forum

Hi Everyone - help for a newbie requested please!

Having installed the software, camera and touchscreen on the Pi all seems to be well, for my next test I want to use 'ugly mode' tx and attempt to receive with a satellite receiver and a modified SUP2400 converter, with the Portsdown TX frequency set at 437Mhz.

As I am (very) new to all this, I would greatly appreciate answers to the following please.

1. Is this likely to work at all?!
2. What would be the best settings at the Portsdown end?
3. What settings are required on the satellite receiver?

Many thanks, and 73

Simon Watson M0ZSU

Hi Simon

Pleased that it all looks good so far. Unfortunately your proposed test will not work:

The maximum symbol rate of the Portsdown in ugly mode is about 333KS/s. The minimum that a normal satellite receiver will work at is 1000 KS/s. You need a MiniTiouner and PC to receive 333 KS/s. Or the Portsdown modulator board (and IQ mode) would transmit up to 4000 KS/s.

The output frequency of the SUP-2400 would be 2400-437=1963. To tune the satellite receiver to this, you may have to tell it that it has a 9.75GHz LO LNB and tune to 9750+1963=11713. It then doesn't matter if you select horizontal or vertical. However, as I said, that is hypothetical, because it won't work due to the symbol rate mismatch.

Hope that explains it and saves you some wasted time.

Dave, G8GKQ

Hi Dave,

Thank you for the quick and informative reply.

I already had a quick attempt to test in this way, so this is in fact good news that it shouldn't work as otherwise my soldering in the SUP2400 was suspected!

I hope to build the MiniTiouner at some stage, but am awaiting construction details for the one that will be part of the Portsdown project.

I have all the bits for the Portsdown modulator board, so I think the best plan will be to get building and then do the test at 1000KS/s or above in IQ mode with that.
Thanks for the details on the satellite rx settings - these will be useful once I have done the modulator board.

Thanks all involved for creating and maintaining this project, I am enjoying it and have already learnt something.

73
Simon M0ZSU