¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io

U3S /5W PA on 2M


Info
 

Hello,

I am having trouble getting power out on 2M (using it as a beacon).

I see 200mv on the collector of the BS170 fet with 5V on the drain.

I peaked the output adjusting the bias, for a clean looking signal on the scope.

Am I supposed to use +12V on the U3S PA+ line?

The 5W PA does amplify the signal, but I fear the drive power is too low.

I do have the VHF fet in the 5W PA board.

This is my first U3S unit.? I am monitoring the unit on a 2M receiver, so I know it is

transmitting, plus looking on a scope.? No power indication on a 15W wattmeter, maybe

the needle just barely moves.

Things to check?

TIA
73

Glen K4KV

Join [email protected] to automatically receive all group messages.