I have a local WebSDR on 2320 MHz which I used to check my SG LAB transverter set to this frequency.
When Es'hail-2 is opened I can change it to 2400 with a jumper setting.
By the time I build this thing in an extra enclosure (with a PA of suitable size, to be determined after opening of the transponder) I will probably make that controllable with an external switch so I can use the same thing for 13cm DX when desired.
I will have an extra SDR (USRP2 w/SBX board) available. I will either listen to my uplink signal locally over the air, or use a Hybrid Coupler (and if needed attenuator) and feed it into the RX2 port of the SBX. [I am planning on being able to combine multiple uplink signals for various experiments/reasons]
TX/RX port on this particular SBX will be an Aux uplink (possibly FT8), while the existing N200 w/SBX will have Primary narrowband uplink and downlink.
The USRP2 and N200 will be phase locked via a MIMO cable, thus enabling ranging and timing experiments
73s
Iain
DB8TF: The N200 was purchased a number of years ago when the exchange rate was far far kinder to us here in the UK [We won't talk about all the reasons it isn't now...], the USRP2 turned up second hand, as did the extra SBX, at a very good price, so I grabbed both of them as soon as I could, realising that there was great potential for experimentation with Es'hail-2/P4A 
Hello...
very easily.
73 Jürgen
Hello Jürgen,
same solution here for testing 2,4 GHz TX 
73 de Johannes
Ah yes I of course have my G0MRF converter for P3d... didn't even think of that!
But I only tested on 2320.2 until now so that is not so practical for now.
Of course once we are on 2400 it can be used...
I use a 13cm converter (2320 MHz) with an additional 80 MHz-block (from PE1JPD 23cm transceiver) and one (1) diode (mixer) to listen to my uplink quality.
I use a California Amplifier MMDS downconverter.
I use a PlutoSDR with SDR# (modified with external reference input to have absolute frequency stability).
vy 73 de DL4TMA
Good idea. I will use my SSB Electronic 13cm downconverter when I buildt up all the AMSAT-DL 'xverters'. Have a look at the Shop.
Hope you understand a question from a "newOne".
Is it important to check the own transmission signal using own "stuff"?
I think i can read the quality of my tx-sigs listening on the RX signal coming from the satellite.
mni tnx for your information
herbert
-most of the time qrv in CW-
That's what I did with AO-40.. works fine. A pair of binaural detectors (ears) and some experience. Not as perfect as modern-day SDRs but good enough.
DL5RDI: exactly what i mean...
I want to be sure that my signal is clean before i transmit over EH2
vy73 DB8TF
A very good and respectable motivation for sure, but if we are honest 99% of all hamradio operators don't do this. Going full duplex as suggested for satellite operations is very helpful here but the round trip time is messing with the brain. It needs a bit of practice to cope with a delayed version of own voice.
We will (hopefully soon) see how different HAMs use different methods to get good and clean signals over the bird. It will be a lot of fun for sure
Back to the "Arabsat Low Noise Downconverter"...
I found a picture on my phone of a measurement from that converter: on 1,25GHz (3650-2400) it has about 12db less gain than in the "normally" used frequency range.
But for simple equipment checks it's ok.
I don't know if this is very interesting but maybe it helps some OMs who are considering to buy such a converter.
vy73 DB8TF
What is the wobbly nature of the Arabsat downconverter passband? Mesurement artefact or feature of the converter?
