S meter calibration

[Kurt V.]

Hi all,

Using the latest thetis v2.10.3.3 for HL2.

I had to go back to a database backup, just simply because my S-meter is showing 9+20 just on white noise, and any station is coming in 9+40 to 9+60. ATT was at 0, so ATT or S-ATT was not the cause. It was on any band.  

I didn't find a way to calibrate or adjust the Signal meter. 

Was my database corrupt or is there a way to adjust or calibrate the signal meter. 

[John Williams]

The best way is to have a calibrated -73dbm source.  I don't have one. You can buy one on ebay or from QRZ in the ham produced products forum. 

I had heard that the SDRConsole was pretty accurate with HL2. So, I loaded it up, went to WWV and found one of the frequencies that was closest to S9. I then launched Thetis and went to that same WWV freq. It was S9+20. I then ran the calibration at that freq with the dbm set close to what SDRConsole read. Bingo, it worked. Now lists close to S9. Is it accurate? Not really, but it is close to reality assuming Simon has SDRConsole pretty accurate. 

John

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From: herme...@googlegroups.com <herme...@googlegroups.com> on behalf of Kurt V. <kvla...@gmail.com>
Sent: Wednesday, November 15, 2023 12:47 PM
To: Hermes-Lite <herme...@googlegroups.com>
Subject: S meter calibration

 

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[Kurt V.]

Thanks for the reply, john. I'm just wondering, where in the thetis software do you configure the S-meter level? 

[John Williams]

General -> Calibration -> Level Cal 

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From: herme...@googlegroups.com <herme...@googlegroups.com> on behalf of Kurt V. <kvla...@gmail.com>

Sent: Wednesday, November 15, 2023 1:40 PM
To: Hermes-Lite <herme...@googlegroups.com>
Subject: Re: S meter calibration

 

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[Ron Lewkowicz]

hpsdrsim generates a -73dBm signal at 14.1 Mhz.  Default setting my meter showed -72dBm so I lowered it by one.  This runs on Mac or Linux. I think there is also a Hermes simulator that runs on Dotnet6 but I don't recall it's name.

[John Williams]

How do you build it and run it. All i find is the github code with no documentation. 

How would one run it to calibrate a Win10/11 based Thetis? 

Sounds pretty complex for the average HL2 user. 

IMHO,

John

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From: herme...@googlegroups.com <herme...@googlegroups.com> on behalf of Ron Lewkowicz <ron.le...@gmail.com>
Sent: Wednesday, November 15, 2023 2:02 PM

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[dh1tt]

Use a generator and calibrate your S-Meter level accurate.

For example your NanoVNA at -13dB plus 60dB attenuator..... = S9

Another cheap solution:

https://www.box73.de/product_info.php?products_id=2740

But..... before you spend this money.....

Go for a Nano VNA or better..... Every Ham needs something like that these days... instead of HT one hundred and thirty seven

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[G4ZAL]

If you have a TinySA use that to set -73db output and inject it into your rig

On TinySA, tap the screen and select 'MODE' --> Switch to 'LOW out'

On the screen tap 'LOW OUTPUT' to 'ON'

Set FREQ to 10Mhz (default)

Slide 'Level:' to -73dBm

Connect the LOW port of the TinySA to your rig Antenna port and calibrate (or adjust your software for an S9 signal)

Done!

Nigel

G4ZAL

[Ron Lewkowicz]

For hpsdrsim on a Linux or Mac that has essential build tools installed already  clone DL1YCF pihpsdr git repository. Install git from your package manager if not on the system. Here are the commands....

git clone https://github.com/dl1ycf/pihpsdr.git

cd pihpsdr/

make hpsdrsim

./hpsdrsim -hermeslite2

Now go to your Windows computer start Thetis and connect to this Hermes device over the network.  If you power down your real HL2 first it should make this simulator show up as the only Hermes device on the network.  Tune to 14.1 Mhz and adjust your meter to show -73dBm.

I'd like to think I'm at least an average HL2 user and I had no trouble with this.  Regardless it's an excellent tool.  It is fully documented in the source code src/hpsdrsim.c

[John Williams]

Thanks Ron. I have built pihpsdr before. 

Sent from my iPhone

On Nov 15, 2023, at 4:32 PM, Ron Lewkowicz <ron.le...@gmail.com> wrote:



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[Don [N5SKT]]

I actually bought one off E-Bay that generates S9 and S4 signals. I use it but on my Anan as it is always high. The Lite has been great in that regard. 

To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/683971AC-2540-49D6-8427-0A5A2D869006%40gmail.com.

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Best Regards,

Don - N5SKT

[Kurt V.]

Maybe a very stupid question, but can I use my NanoVNA to generate the s9 signal? 

And if it is possible, how to do? Is there any info available on this? 

[Cliff]

Thanks Ron,

I installed hpsdrsim on Debian in a virtual machine and networked to the main OS works a treat , tried it with SparkSDR on my MacMini

Next to try it with Win10 and Thetis , 

Cliff VK2NP

[Alan Hopper]

Hi All,

I'm interested to know if anyone has a proven calibration value for SparkSDR or if they know if hpsdrsim's output is valid for hermeslite ( the gain from antenna to iq is not the same as Hermes).  I honestly can't remember how the default value was set.

73 Alan M0NNB