Hermes Problem with Power / SWR

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Posts: 26
Joined: Fri Dec 29, 2017 10:36 pm
Location: Germany

Hermes Problem with Power / SWR

Postby DH1KLM » Mon Jan 13, 2020 2:55 pm

Hello community,
after a few attempts with Pure Signal, I seem to have a problem with my Hermes Board.
I use the Themis coupler from F6ITU Marc V2
After PowerSDR always complained about too little feedback (Feedback is blinking red),
I changed the windings of the toroidal cores, but I made a mistake while soldering them in. : cry: (Power-SWR display worked before)
D1 on the coupler board died in succession, almost certainly also the LMC6482, which delivers now permanent
4.05V to FWD / REF since then, to the Hermes Board, not good.
But I didn't notice it immediately and this voltage was fed into the Hermes Board.
Already have ordered a replacement LMC6482 for the coupler.

Since then, PowerSDR always showed me 41W output power in TX,
regardless of the actual output power, even though the power measurement can no longer take place because the coupler is no longer connected to the rest.

I be scared that the Hermes Board has also suffered damage.
How likely is it that U17 ADC78H90CIMT is now defective as a result? This should actually evaluate the FWD / REF signal.
How can I verify that?

Otherwise, the board works perfectly. Will now test Prot.2 with Thetis, let's see what is shown here.

// it's exactly the same under Thetis! //

Could someone who owns a Hermes board please check how much power is displayed in PowerSDR if no SWR / Power coupler
is connected.

I would be very grateful if someone could help me.

Coupler schematic
themis-schematic.PNG (30.29 KiB) Viewed 2139 times
73 de Sigi / DH1KLM
Posts: 26
Joined: Fri Dec 29, 2017 10:36 pm
Location: Germany

Re: Hermes Problem with Power / SWR

Postby DH1KLM » Wed Jan 15, 2020 11:02 am

Everything sorted out. LMC6482 was broken. Thankfully, no further damage has been done.
It looks like the LMC6482 has had a problem right from the start.
The only issue to get rid of is that PS feedback is going blue at about 20W.
Now I had to rewrap the toroids again.
So far so good.

73 de Sigi / DH1KLM
73 de Sigi / DH1KLM

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