Offers are being considered and are responded to quickly. Amplifier Research model 5S1G4, 5 watt laboratory RF/microwave power amplifier with adjustable gain. I used it as recently as last week, when I took the VNA sweeps. 5 Watts maximum linear output e.
5W is the output 1dB compression point over an operating frequency range of 800 MHz to 4.2 GHz. You might get a couple more watts before complete saturation. The gain is adjustable with the simple turn of a knob. The specification says it can vary from 27 dB to 37 dB, but I seem to get it to go up to 44 dB at certain frequencies (see VNA trace). Input and output connectors are both 50 Ohm type N(f).
This is currently set for North American power. 38 pounds (17.3 kg). 19.8(W) x 6.1(H) x 11.8(D) inches (50.3 x 15.5 x 30 cm). A few scuff marks and a couple of places with tape residue. Rack mount hardware not included. This item is in the category "Business & Industrial\Test, Measurement & Inspection\Signal Sources & Conditioning\RF & Microwave Amplifiers". The seller is "testlab25" and is located in this country: US. This item can be shipped worldwide.