toggle quoted messageShow quoted text
Yes, the TX rail has 12v on it whenever the rig is transmitting, 0v when it is not.
Probably your best choice, and easy to tack a wire on it.
Does your amplifier really want a 12v signal, or something more like 5v?
How much current will the amplifier draw from this signal?
I would think about limiting the current somehow, perhaps a series resistor inside the uBitx.
Otherwise a miss-wire in the cable could cause 10 Amps to flow, and lots of smoke.
On Tue, Mar 16, 2021 at 10:38 AM, Rob French (KC4UPR) wrote:
I'm looking to add a PTT-OUT to the back panel of my uBITX, to control e.g. an amplifier or a switch to isolate an external SDR during transmit.
My thought is to grab C154/D11 or one of the other filter-switching relay circuits. Those look like easy places to tack a short wire to without having to completely disassembly my uBITX.
Two quick questions:
(1) Dumb question... but that junction does provide what I want, right? i.e. +12V on transmit.
(2) Any downsides to tapping the +12V on transmit, from that location? e.g. some RFI effect