ATS25 AMP mistake update

[G8PTN]

Can anyone tell me if it is possible to decode the PSK31 with an ats25 AMP ?

Yes, it should be possible with the V4.17 firmware.
However, it should be noted that the ATS25-AMP is not officially supported (see previous messages).
The setting.ini file needs to be updated and downloaded to the receiver (see previous messages).
73, Dave

[G8PTN]

The ats25 AMP has an LNA, does it work well ?
Does it have good reception with or without the LNA ?

Hi,
In my view, the LNA does appear to work (provides RF gain), but I can’t compare the performance against the ATS25 Max Decoder.
In some cases, it may provide too much gain and therefore cause overload.
Overall, the ATS25-AMP seems to work well for a low cost receiver.
73, Dave

[radi0]

Good morning,
Thank you for your answers,
I just watched a video on YouTube from an owner of ats25 amp who shows us a Version 4.17 (official or not ) he also tests the LNA

Vidéo YouTube https://youtu.be/PjWIO8LOzkE?feature=shared

Good day to you

[radi0]

wonder about these voltage problems, and to avoid installing a boost circuit if the simplest thing would not be to change the original 3000 mAh battery with one of 6000 or even 10000 mAh
on aliexpress there are batteries for a few euros/dollars

see if the sizes are right for it to fit in the RX
(Sizes: 12*60*110mm)

Link batterie aliexpress
https://fr.aliexpress.com/item/10050036 ... 0e16929f30

[G8PTN]

I just watched a video on YouTube from an owner of ats25 amp who shows us a Version 4.17 (official or not ) he also tests the LNA

Hi,
Yes, although the version displayed on delivery is shown as "4.17 Air beta", it is actually a hybrid version of "4.16 Air" with the LNA and HI-Z features enabled.
73, Dave

[G8PTN]

wonder about these voltage problems, and to avoid installing a boost circuit if the simplest thing would not be to change the original 3000 mAh battery with one of 6000 or even 10000 mAh

Hi,
The problem is not so much the capacity (mAh), but the voltage. The nominal voltage is 3.7V, fully charged 4.2V and discharged 3V.
The components (ICs) in the Digi Decoder circuit are specified for nominal 5V operation. In practice they work below this voltage, but are not guaranteed. Increasing the battery capacity may help to increase the time before a low voltage problem occurs.
The battery you have shown would not fit in the ATS25-AMP, but other higher capacity variants should fit. Check the battery thickness, since it sits under the PCB.

The enclosure is approximately 112 x 102 x 48mm.

Note: If the battery is changed, you will need one with the protection circuit, or add it separately. There is no protection on the ATS25 AMP board.

73, Dave

[radi0]

Yes, the aim of adding a 10,000 mAh battery is simply to bring the voltage down as slowly as possible to a critical voltage for the decoding chip.
The problem with a 5 v voltage booster is the parasites it produces, we must not forget that he installed an LNA in the rx. I think this is why the manufacturer of the asp25 AMP did not install the 5 v boost.
Does it work properly with the USB cable plugged in all the time?
do you have the version of esp32 in the ats25 AMP? do you know its supply voltage?
Sincerely

[G8PTN]

The problem with a 5 v voltage booster is the parasites it produces, we must not forget that he installed an LNA in the rx. I think this is why the manufacturer of the asp25 AMP did not install the 5 v boost.

Hi,
Yes, all understood.
The modification that I made was just to add a low power charge-pump to the Digi Decode circuitry. This is what is used on the ATS120D decoder board. There will still be some conducted noise feedback to the battery supply and radiated emissions, so it is not ideal.
The logic level for the CW/RTTY decoder signal (without the 5V boost) can be fixed by changing the arrangement of the pull-up resistor on the LM567 output (see previous messages).

With the USB cable plugged in, the battery voltage will get close to 4.2V, but the charger chip is switched mode (for efficiency), so that will also create noise. Charging will not terminate when the receiver is switched on because the current does not drop to the cut-off threshold.

The ESP32 is marked "ESP32-WROOM-32U". The nominal operating voltage is 3V3 and the specified range is 2.7V to 3.6V.

As previously stated, the ATS25-AMP will generally operate correctly, so for the cost of the receiver and performance you will get, it’s probably best just leaving it as is.
73, Dave

[radi0]

I have just looked at the datasheet of the decoder (HT567) it has a minimum operating voltage of 4.75 volts it must be replaced by an LM567 in the datasheet of this component its minimum voltage is 3.5v instead of 4, 75 v minimum for the original HT567 component to be tested

I wonder if for the liw voltage audio HT386 chip which has a minimum voltage of 4 volts we could not change it against a TDA2822M with a minimum voltage of 1.8 volts

[G8PTN]

I have just looked at the datasheet of the decoder (HT567) it has a minimum operating voltage of 4.75 volts it must be replaced by an LM567 in the datasheet of this component its minimum voltage is 3.5v instead of 4, 75 v minimum for the original HT567 component to be tested

Hi,
Yes, although is should be noted that the electrical characteristics for the LM567 are shown with a minimum voltage of 4.75V.
The LM386/HT386 is also operating below its specified minimum voltage of 4V.
73, Dave