WSPR - QRP-Labs U3S

My new U3S is online :-)

I build my own 5-band version of G0UPL famous U3S kit kit. I placed it in an BOPLA ULTRAMAS cases.

The powersupply is a cheap chinese step-down-converter for the 5VDC rail of the U3s. For the PA power I used a LM317 based variable linear regularor.

Output power

The U3S with one PA FET gives the following output power:

The power readings are from home-build RF powermeter.

References

Please check also these articels:

• Signal quality
• Low-pass filters