External connections - Rear - EXTRR

[Jean-Baptiste GALLAUZIAUX]

What signal comes out of this connection?

I'm considering building a QRP-Labs 50W Amp for QCX and use it with my HL2 on my favourite band in CW. This monoband amplifier requires a +5V signal for PTT. Does the signal coming out of EXTRR fit this requirement?

73 - Pierre - FK8IH

[Luke Williams]

It is open collector and is pulled low (to ground) during transmit. This is ideal for most amps as long as they use solid-state switching and not a higher voltage or need more current. Full details here:

https://github.com/softerhardware/Hermes-Lite2/wiki/External-Connections#exttr

Since the QRP Labs amp is backwards, you will need to build a small inverter circuit that goes to +5V when EXTTR goes low. If you have the optional IO board, this could be accomplished pretty easily on it. If it would key with +3.3V that the Pico uses, then a small bit of firmware would do it even if it is overkill.

Luke - AE5AU

[Jean-Baptiste GALLAUZIAUX]

Thanks Luke. Do you know the Neptune 50W manual Amplifier https://www.60dbm.com/product/50-w-hf-50mhz-power-amplifier-ft-817-icom-703-icom-705-elecraft-kx3/ ? If I buy it with the HL2 cables https://www.60dbm.com/product/cable-kit-for-neptune-amp-and-hermes-lite2/ does it work directly without any modification of the HL2? Where is plugged the RCA PTT cable, in the EXTRR socket?

73 - Pierre - FK8IH

[Luke Williams]

Based on their listed specs, it should be no problem:

• External PTT signal – GND active,  RCA female connector, <1 mA sink current, no relay required

Here are the full details on the EXTTR on HL2:

https://github.com/softerhardware/Hermes-Lite2/wiki/External-Connections#exttr

Luke

Sent from my iPhone

On Jul 18, 2024, at 22:01, Jean-Baptiste GALLAUZIAUX <jb.gall...@gmail.com> wrote:

Thanks Luke. Do you know the Neptune 50W manual Amplifier https://www.60dbm.com/product/50-w-hf-50mhz-power-amplifier-ft-817-icom-703-icom-705-elecraft-kx3/ ? If I buy it with the HL2 cables https://www.60dbm.com/product/cable-kit-for-neptune-amp-and-hermes-lite2/ does it work directly without any modification of the HL2? Where is plugged the RCA PTT cable, in the EXTRR socket?

--
You received this message because you are subscribed to the Google Groups "Hermes-Lite" group.
To unsubscribe from this group and stop receiving emails from it, send an email to hermes-lite...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/89ff97c2-c60b-4abb-b989-e8e8d800831en%40googlegroups.com.

[Robert Muir]

I'm using the Neptune 100 amp , just plug cable into EXTRR socket and no mod on hl2