In search for a suitable pre-amplifier for the SG-Labs PA V3 I was pointed by a fellow ham to this amplifier on Amazon for abt.€17,-
The advertised gain was 40dB - lets check this out :-)
Measurement
Setup
- Siglent SSA3021X with tracking generator
- 40dB attenuator on RF input -> so add 40dB to the measured signal on the SA
Data @ 2.4GHz
| Input (dBm) | Gain (db) | Output (dBm) |
| -20 | 34,4 | -25,6 |
| -17 | 34.2 | -22,8 |
| -15 | 33.6 | -21.4 |
| -10 | 30.0 | -20.0 |
Conclusion: Maximum input power @ 2.4GHz is about -20dBm
Data @ 1GHz
| Input (dBm) | Gain (db) | Output (dBm) |
| -20 | 39.8 | -20.2 |
| -17 | 37.6 | -19.39 |
| -15 | 35.7 | -19.24 |
| -10 | 30.75 | -19.25 |
Conclusion: Maximum input power @ 1GHz is about -20dBm
Conclusion
The advertised amp gain of 40dB will be nearly reached at least at 1GHz.
The maximum output power of +20dBm (100mW) will be also reached at 1GHz.
At 2.4GHz the maximum output power is abt. 14.4dBm (28mW).
Usability for QO-100 Uplink
To use this amplifier as a preamplifier in front of the SG Labs V3 PA will result in an (estimated) ouput power of 14W.
Lets check again the real amplifier when it arrives.