Pure Signal using VK-AMP RF sampler

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Kurt V.

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May 13, 2024, 6:04:49 PM5/13/24
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Hello All,

I have now put the VP-AMP sampler in line behind my beloved OM2000+ amplifier. 
How can I be sure that the Pure Signal is using the signal from the RF-Sampler behind the amplifier and not the internal RF (internal Pure Signal)? 
I am confused as I don't see any checkbox in Thetis to force to use the external RF signal from the sampler.

Just for the record: I am feeding the VK-AMP RF sampler into the Hermes Lite 2 using the extra external connector I had to solder inside the HL2 using the information from these pictures:

Thanks for any help

RdWing

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May 14, 2024, 2:42:08 AM5/14/24
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There is no option. There is no internal sampler in the HL2. Any thing you see is just crosstalk in the internal relays. Now that you've added the sampler and jumper you should be good to go.

"Christoph v. Wüllen"

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May 14, 2024, 3:40:55 AM5/14/24
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HL2 cannot switch the signal path for the feedback signal.

This means, even if you use a sampler and feed it to the HL2, it will see BOTH
the feedback signal (from BEHIND the PA) and the T/R relay crosstalk (from BEFORE
the PA).

So what you have to do is to make the feedback quite strong such that it requires
maximum attenuation in the front end, then it will "win".
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Kurt V.

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May 14, 2024, 2:41:21 PM5/14/24
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Hi all, Hi Rdwing & Christoph,

Thanks for your feedback. I noticed the A-ATT goes to 31 when I'm at full output power. I guess this means that the input from the RF Samples is a little too high. I get this issue when I'm going legal limit. When I go half of legal limit, it seem the A-ATT goes to about 24. I guess I'll need an extra attenuator of 6Db to not overload the RF input into the HL2? 

Kind regards. 

Kurt

"Christoph v. Wüllen"

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May 15, 2024, 2:55:57 AM5/15/24
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I cannot answer any questions regarding Thetis (in piHPSDR the ATT
slider for HL2 is a Gain slider and goes from -12 to +48, which
correspondes to the hardware).

But in the PS menu you should see whether the automatic attenuation
gets your feedback amplitude in the right ballpark. There is a
colour code for "too low / just right / too high", and for
reasons explained earlier, use a feedback attenuation as low as
possible.

An additional 6 dB attenuator on the "low power side" is
easy enough, though.
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RdWing

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May 15, 2024, 3:38:45 AM5/15/24
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Please check as Christoph said, if you are seeing Red/Green/Blue in the lower right corner of the pan adapter while transmitting. 

You should have PS-A turned on, and I like to additionally check the “Quick Attenuate Response” box in the PS setup menu. 

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