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.

2014 CW (Morse Telegraphy) was added to the German Nationwide Inventory of Intangible Cultural Heritage.

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