Pure signal optimal parameters

[Luca De Biase]

Hi all, 

Richie mw0lge, has written an interesting calculator of the optimal parameters for setting up anan sdr and samplers for best results with pure signal.

He has the parameters for anan radios but not for HL2.

Here the Richie's message:

7000/8000/G2's use 14dB pre-amps before the ADC, other Anan's use 20dB pre-amps. Ideally the input to the ADC should be around +3dBm. We aim for a 25dB step attenuator setpoint to minimise cross talk and to hopefully obtain a good clean puresignal sample to the ADC. The tool takes the pre-amp difference into consideration. I do not know the characteristics of the HL2 in this regard.

...

I ask, especially to Steve, if he can write here the same parameters but for HL2 so i can pass them for eventually add a correction to the calculator for the HL2 .

Here the link of Richie's work:

https://ramdor.github.io/coupler_calcs.html

73, Luca ea8djr

[Steve Haynal]

Hi Luca,

Thanks for the interesting link. The HL2 has a variable LNA before the ADC, -12 to +48 dB. Also, some of the FPGA coefficient values are different due to 12-bit architecture and DSP gains for the HL2's samping rate.

73,

Steve

kf7o

[Martin Domino]

Received this in the mail today
I'm a little curious if there are any people who use it for pure signal
And maybe have some experience with settings.
It has a -50dB OUT

I use CM AISO with a Yamaha AG03
THETIS v2.10.3.11

And Happy New Year
OV60/OZ9MSD

[Ezio Insinna]

Hi Martin.

HNY 2026. 

Can you advise about your supply source for this coupler ?

Thanks, 73

Ezio - F5MWA / K3EK

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[Luca De Biase]

i use it , works well. nice coupler , good quality and good price

[Luca De Biase]

Hi Steve, thanks, i will try to pass to Richie the info.

Also i have another question: From several versions for hl2 on , i see in the linearity window , just near the standard value of 0,233, one yellow alert sign. If I click on the button default , the sign disappear but the standard value is stil 0.233. I don't understand what is wrong...

Can you explain me?

Thank you so much

73

Luca

[Martin Domino]

I think it's some kind of home production.

but it looks really nice
sold by Symkrilag UK - www.symkrilag.uk

[Juergen Hussels]

Hello,

I have made very good experience with a homebrew sampler like the one mentioned by N4GA https://www.n4ga.com/50db-hf-rf-sampler/.

The sampler is based on ideas from W5QN https://www.collinsradio.org/wp-content/uploads/2015/05/Build-a-Quality-RF-Power-Sampler-Jackson.pdf

However I build one with 60dB and one with 40dB attenuation - caculated from the formulas given by W5QN.

I used a 3.3Ohm to gnd and a 47 Ohm in series to the sample output.

The reponse of the 60dB is flat from 1MHz to ca. 150 MHz with a Amidon /Micrometals T68-2 red toroid. Even with 1kW the core does not get hot. I put this in a tin box 32x32x30 mm 

The 40 dB is from 3,5MHz to 440MHz (maybe I should try a fair-rite ferrite core instead for lower cut-off) . I used 2502 SMD resistors

cheerio & 73

Juergen DL4JY

To view this discussion visit https://groups.google.com/d/msgid/hermes-lite/e6a6489d-3460-42da-ac1a-aa4789602ca8n%40googlegroups.com.

[Martin Hertkorn]

Hello , 

i have the following Issues with Pure Signal in to I/O Board, if i plug in the line from the  Amplifier through my RF Coupler i have a good Value from about 150 green feedback , but if i connect my RX Antenna, it goes up to 270blue and the Auto Attuanator can't bring it to 150, someone else have seen this Issue.

73 Martin, HA3AN

["Christoph v. Wüllen"]

Obviously your RX antenna is not well decoupled from your TX antenna,
it takes up your TX signal and provides it, as a very strong signal,
to the radio.


You have to ground/disconnect your RX antenna while TXing.

> Am 12.01.2026 um 09:34 schrieb Martin Hertkorn <martin....@gmail.com>:
>
> Hello ,
>
> i have the following Issues with Pure Signal in to I/O Board, if i plug in the line from the Amplifier through my RF Coupler i have a good Value from about 150 green feedback , but if i connect my RX Antenna, it goes up to 270blue and the Auto Attuanator can't bring it to 150, someone else have seen this Issue.
>
> 73 Martin, HA3AN
>
> Juergen Hussels schrieb am Montag, 5. Januar 2026 um 23:50:14 UTC+1:
> Hello,
> I have made very good experience with a homebrew sampler like the one mentioned by N4GA https://www.n4ga.com/50db-hf-rf-sampler/.
> The sampler is based on ideas from W5QN https://www.collinsradio.org/wp-content/uploads/2015/05/Build-a-Quality-RF-Power-Sampler-Jackson.pdf
>

> However I build one with 60dB and one with 40dB attenuation - caculated from the formulas given by W5QN.I used a 3.3Ohm to gnd and a 47 Ohm in series to the sample output.

>
> The reponse of the 60dB is flat from 1MHz to ca. 150 MHz with a Amidon /Micrometals T68-2 red toroid. Even with 1kW the core does not get hot. I put this in a tin box 32x32x30 mm
> The 40 dB is from 3,5MHz to 440MHz (maybe I should try a fair-rite ferrite core instead for lower cut-off) . I used 2502 SMD resistors
>
> cheerio & 73
>
> Juergen DL4JY
>
>
> Am Mo., 5. Jan. 2026 um 22:22 Uhr schrieb Martin Domino <martin7...@gmail.com>:
> I think it's some kind of home production.
> but it looks really nice
> sold by Symkrilag UK - www.symkrilag.uk
>
>
> mandag den 5. januar 2026 kl. 19.12.24 UTC+1 skrev Ezio Insinna:
> Hi Martin.
>
> HNY 2026.
> Can you advise about your supply source for this coupler ?
>
> Thanks, 73
>
> Ezio - F5MWA / K3EK
>
> On Mon, Jan 5, 2026 at 4:07 PM Martin Domino <martin7...@gmail.com> wrote:
> Received this in the mail today
> I'm a little curious if there are any people who use it for pure signal
> And maybe have some experience with settings.
> It has a -50dB OUT
>
> I use CM AISO with a Yamaha AG03
> THETIS v2.10.3.11
>
> And Happy New Year
> OV60/OZ9MSD
>
>
>

> To view this discussion visit https://groups.google.com/d/msgid/hermes-lite/6b971de7-c4f6-4c8a-ad3c-f495168df800n%40googlegroups.com.

[Martin Hertkorn]

Thanks Christian, okay so obviously thats the Issue, so there should be a relay if i go to transmitting which ground the RX port.

73 Martin