Connect a linear amplifier to hermes lite 2

2,328 views
Skip to first unread message

Michel Sabatino (IZ5CLJ)

unread,
Mar 28, 2023, 6:03:32 PM3/28/23
to Hermes-Lite
Hi.

I cannot run my external amplifier from the hermes lite.
I am using thetis 2.9
I have connected a cable from the port EXTTR to the amplifier.
How do I instruct the software to ptt the amplifier?

Thanks in advance.
73, Michel.

Andy-ik7ytt

unread,
Mar 28, 2023, 7:43:58 PM3/28/23
to Hermes-Lite
if enable pa and enable full duple are both on. you are ready to go in tx. 
EXTTR is automatically enabled.

Gerrit Heijting

unread,
Mar 29, 2023, 2:12:52 PM3/29/23
to Hermes-Lite
Hi Michel,

Tested here and connected a ohm meter with Beep to  EXTTR.
If the TX led is lit then I hear Beep.
So its ok here.
I connect my first lineair tomorrow so I tested now.
Software used is sdr-console.

Have a nice day,
73's Gerrit

radi...@mail.com

unread,
Mar 31, 2023, 10:17:34 AM3/31/23
to Hermes-Lite
See here (EXTTR) for details of the port.

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

I have just made straight connection to my DX World-e linear and keys it fine.

What is your amplifier and what are the specifications of the PTT line on the amp?

Max

Michel Sabatino (IZ5CLJ)

unread,
Mar 31, 2023, 1:54:07 PM3/31/23
to Hermes-Lite
Hi.
Thank you for your help.
My linear amplifier is an ACOM 1000.
It requires "ground on transmit" to be keyed.

Thanks again.
Michel.

Antonio Del Manto

unread,
Dec 4, 2025, 11:05:28 AM (10 days ago) Dec 4
to Hermes-Lite
Hi, I also have a PA (OM POWER 3500 HF), but to connect it to the HERMES LITE 2, should it be enough to connect the PTT from the HERMES to the PA? I have 3 SDRs that I've been connecting this way for years and they work fine!! Maybe the HERMES has something different? Thanks.

Antonio Del Manto

unread,
Dec 4, 2025, 11:14:03 AM (10 days ago) Dec 4
to Hermes-Lite
OM POWER 3500 HF

I connect the other SDRs I have with the PTT...

PTT sdr-PA



--
You received this message because you are subscribed to a topic in the Google Groups "Hermes-Lite" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/hermes-lite/bivbrLsBumw/unsubscribe.
To unsubscribe from this group and all its topics, send an email to hermes-lite...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/hermes-lite/04af3208-e936-49c0-ae49-48416a624d0cn%40googlegroups.com.

Joey G.

unread,
Dec 6, 2025, 5:55:35 PM (8 days ago) Dec 6
to Antonio Del Manto, Hermes-Lite
I think I had a similar issue but finally just used a 5v relay with diode across the coil connected to the Hermes PTT out to trigger the ground side of the relay.  It only pulls like 40ma when in TX so I don't think it's hurting anything directly driving a small relay from the PTT out.  The PTT out will work directly with my RM Itali amp but not other amps I have, so I had to do this relay fix on my other amps.  Just use a small relay and keep an eye on the amps it pulls. 

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 visit https://groups.google.com/d/msgid/hermes-lite/CADj-qweRsXfc7B%3DziV-oiGkg%3D6KrjOxemKiG5%3DgyJcvncN3%2BKg%40mail.gmail.com.

Jerry Kaidor

unread,
Dec 6, 2025, 8:08:48 PM (8 days ago) Dec 6
to Hermes-Lite
I have connected my HL2 to my homebrew LDMOS linear.  The linear requires a minimal-current pull to ground for PTT.  It also needs
Yaesu "BCD" band codes - four wires each of which is either high ( +5V ) or low, forming 16 possible codes.  I used the I/O board for this, and a kind subscriber on this list gave me the code to run it.   For just PTT, the HL2 should be able to do it as is.  But there is a current limit for the output transistor - forget what it is.

                           - Jerry, KF6VB
Reply all
Reply to author
Forward
0 new messages