My new U3S is online :-)

U3S 2

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

U3S 1 U3S 4 U3S 5

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:



5.366.127 21,68
7.040.023 22,60
10.140.223 21,52
14.097.173 21,28
50.294.493 21,36

The power readings are from home-build RF powermeter.


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

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