https://aliexpress.ru/item/1005006114325611.html
Maximum output with 30v input voltage on HF band — 1.369 watts:
More input power — failed output:
It hasn’t any transformers so output power depends on input voltage and as maximum voltage is 30v it’s impossible to get 4w watts output.
Most test I have done using 13.8v voltage:
160m:
80m:
40m:
20m:
10m:
2m:
70cm 36db external attenuation — still the same good output (HackRF as a signal generator) — 27.8dbm output — 15.52v P2P — ~0.6watts:
Harmonics 80m, forgot to set markers for them 🙁 To put it short — it’s acceptable:
As first stage for 100W amp. only 60mV P2P input:
134.6 watts output with my 2 stage rd16+rd100 amp.
Conclusion:
It’s pretty good cheap wideband 0.6watt output (with 13.8v supply voltage) amplifier. Maybe it will be a good idea to change thermal paste and add solder on the output transistor (I did both). Don’t know how people firing it (comments on the aliexpress) it’s pretty stable, just control temperature.