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pavel-demin / red-pitaya-notes

Notes on the Red Pitaya Open Source Instrument
http://pavel-demin.github.io/red-pitaya-notes/
MIT License
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hpf problem ? #664

Closed F6ITU closed 6 years ago

F6ITU commented 6 years ago

Description of the setup:

bad hpf switching behaviour

Description of the problem:

It seems that the lpf spi commands are incorrectly handled for the 9.5, 13 and 20 MHz filter commands. All other switching are perfectly decoded by the TPIC6B595 and working (Att 1 & 2, by-pass, 6m_LNA/50 MHz, 1.5 MHz and 6.5 MHz)

Once the 6.5 MHz limit is passed, the 6.5 hpf filter stays on and is not released when passing the next crossover point (theorically 9.5 MHz)

... and thus till the frequency reachs 50 MHz.

Steps to reproduce the problem:

  1. plug an spi interface into E1 of the Red Pitaya

  2. Power-up, launch PowerSDR with "Alex" filter set declared in the general configuration screen, Alex filter configured in "firmware" mode

  3. Sweep frequencies from 0 to 60 MHz

I built 2 different interfaces just in case the problem could be caused by a faulty TPIC6B595. Same mis-functionning The former image gave me the same results

... it could also be a PEBCAK question, but I couldn't find where I made a mistake.

Marc

pavel-demin commented 6 years ago

Could you please check if it works better in the manual mode?

I've checked the code but can't see any problem.

Could it be due to the following line in sdr-transceiver-hpsdr.c?

freq = freq_data[1] < freq_data[2] ? freq_data[1] : freq_data[2];

The minimal frequency of the the two receiver frequencies is used for the high-pass filter. This is how the Hermes firmware behaves (look for C122_freq_min in Hermes.v).

F6ITU commented 6 years ago

Thks Pavel I'm QRM for the next 7 days.. I'll check this (hard and soft ) asap and will keep you informed.

As far as I can remembrer, the "manual mode" was not responsive, but I didn't pay attention to the general configuration of PowerSDR (considering that the default config was "firmware")

Sorry for the delay 73' Marc