Kaits
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If you use a combiner, there should be no "interrupting" as you describe. Try to connect the "interrupting" input to the "healthy" input of your combiner, and/or test the suspected source separately.
Without more details, it is difficult to offer an advice.
From the details you wrote I think the problem may be in the final-stage mismatch protector in one of the signal sources.
Please try to insert 3-dB attenuator pads into each of the inputs, and try to connect a termination instead of the antenna.
High-power signal sources (transmitters) often use an automatic switch-off for a mismatched load. One may be more sensitive than the other, or your coupler has a poor isolation.
In any case, attenuating the inputs may show if it helps, otherwise I would try another power combiner before SSPA.
Did the both upconverters using with same freq oscillator (TCXO etc)
if not please syncrosize them...
If I understand your problem correctly u connect two "different" signals into the combiner by different I mean they dont have same phase...
David
Hi
Lets do example take u Power combiner and 2 different Signal generator
Define both of them (Signal gen) same freq and same power 0 dBm for example and 1GHz
Connect both signal to input of the combiner and sum port to Spectrum analyzer...
The results that u will see that signal will jump from 3 dBm to -3dBm (or something...) But u for sure will not get 3dBm const...
Splitter and Combiner it not the same "animal"...
U have the same problem at u system is not synchronized...
David
If adding an attenuator helps, it indicates to me that the load (the coupler or combiner) reflects back enough power to trigger the mismatch-protection circuit in the signal source.
If you can, try to use another power combiner, or, find by a reflectometer (or SWR meter) why the mismatch occurs and correct it. RF power sources like yours need such protection as by the reflected power the final stage could overheat and be damaged.
Another solution may be using a ferrite isolator if available for your frequency and power level. Its internal termination must be rated to absorb the reflected power without overheating.
Try to take fundamental freq from one of the upconverters and inject it to the other as fundamental (disable the internal one and the second unit)
and than retest...
David
Sorry I mean The modem connected to Transceiver 1 usually the carriers goes off and on when combined with Transceiver 2, modem connected to Transceiver 2 function normally. But when decreasing down converter attenuation for Transceiver 1 somehow it affects the modem connected to Transceiver 2 meaning that the modems connected to Transceiver 2 alarms.Can u please more details as I don't really get what u mean... by the way, here is a diagram of my set up..View attachment 67601
The modem connected to Transceiver 2 works normally and the modem connected to Transceiver 2 usually turns on and off..
Can u please more details as I don't really get what u mean... by the way, here is a diagram of my set up..View attachment 67601
The modem connected to Transceiver 2 works normally and the modem connected to Transceiver 2 usually turns on and off..
Please can you advice solutions as how I can syncronize the two upconverters.Hi
According to u schematic
U inject from two different modems to two different upconvetrers...
and then u taking it to amp thru combiner...
Once again I am pretty sure that u problem that fundamental of both modems are not syncronized...
David
Can u please see this combiner (as attached)Now, having seen your schematic of actual connections, I want to ask: Why don't you use the power combiner AFTER both HPAs? Something in your connection is affecting one of both carriers from the two modems, but as you wrote, you saw some improvement if you attenuated one or both inputs to the one HPA. It again indicates for me that there may be some protection circuit, in the HPA or in the modem, which triggers reducing carrier power.
As you have two complete transceivers and use another power splitter (or combiner) in the lines from antenna to the two receivers, why not try to use the power combiner AFTER the two HPAs, to one antenna?
Satellite transceivers often have protection circuits that limit the carrier maximum power, watch for a mismatch at the RF output, etc. Maybe it is time to read the manual....
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