No Tx power out

Kevan Wilson

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Jul 30, 2026, 8:37:05 PM (8 days ago) Jul 30

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The Hermes stopped making power. No output on the watt meter no power out on the Thetis meter. I see my modulation on the pan adapter and hear my transmit on a nearby reciever. No power out to meter.

Steve Haynal

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Aug 1, 2026, 2:05:28 PM (6 days ago) Aug 1

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Hi Kevan,

I suspect something changed in your software setup to disable the PA and use the low power output. That would explain why you still hear your transmit on a nearby receiver. Can you check your software settings? Please share which software you are using and screenshots of the configuration pages.

73,

Steve

kf7o

Kevan Wilson

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Aug 1, 2026, 11:12:14 PM (6 days ago) Aug 1

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Steve the radio dropped out while I was talking. I suspect either 1 or both of the aft504"s have failed. In circuit they show 24 ohms from gate to ground and also almost a short from drain to ground.

I did use good heatsink compound on the heat sink and it was all good.

Just bought this last month but can't find the reciept.

Steve Haynal

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Aug 2, 2026, 9:11:37 PM (5 days ago) Aug 2

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Hi Kevan,

I can't read the pictures you sent due to low resolution. The final PA LDMOS devices are pretty rugged against high SWR. There is also a mechanism to disable the PA when temperatures are high. It could be the Vpa voltage regulator has gone out, or the temperature sensor is pegged to think there is always high temperature, or you software settings are incorrect, or audio data is no longer being sent to the HL2. Please:

1. Resend you pictures at a readable resolution

2. Read through and perform checks as seen on this wiki page: https://github.com/softerhardware/Hermes-Lite2/wiki/No-Transmit

In particular, the CW key test (bypasses audio from your software, software must be in CW mode), trying other software, measuring Vpa, reporting the bias and temperature measured by software (and which software you are using) would be helpful.

73,

Steve

kf7o

Kevan Wilson

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Aug 6, 2026, 11:51:51 PM (2 days ago) Aug 6

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Kevan Wilson

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Aug 6, 2026, 11:52:23 PM (2 days ago) Aug 6

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Kevan Wilson

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Aug 6, 2026, 11:53:19 PM (2 days ago) Aug 6

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Kevan Wilson

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Aug 6, 2026, 11:53:45 PM (2 days ago) Aug 6

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On Thursday, August 6, 2026 at 10:53:19 PM UTC-5 Kevan Wilson wrote:

Kevan Wilson

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Aug 6, 2026, 11:54:24 PM (2 days ago) Aug 6

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Kevan Wilson

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Aug 6, 2026, 11:54:58 PM (2 days ago) Aug 6

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Kevan Wilson

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Aug 6, 2026, 11:58:22 PM (2 days ago) Aug 6

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Steve I apologize for the ay I sent the pics. Not used this page much. I still have my old HL2 and it works fine in Thetis. This new one just quit making power.

On Thursday, August 6, 2026 at 10:54:58 PM UTC-5 Kevan Wilson wrote:

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