BATC Forum

Hi all

First of all a great thank you to Simon and his crew for developing the SDR Television.

Today I made a comparison of SDR TV's capability to detect weak signals. I did the test together with two fellow amateurs. One was reveiving using a MiniTiouner and two were receiving using Plutos and SDR TV. We all three use 120 cm dishes, and we all looked at the same TX signal (my testcard with a running text). We are all able to see the increment in the noise floor on the downlink signals, so the antennas and LNBs work as they should.

With FECs 2/5, 1/2 and 3/5 the system using the MiniTiouner was able to detect and stream signals down to 1.7 dB above the theoretical limit whereas the systems running SDR TV stopped detection 2 to 2.5 dB higher, i.e the limit was around 4 dB above the the limit.

Before we embark on a larger fault finding mission, may I ask if others have tried to compare the detection capability of SDR TV with other systems.

Vy 73

Jorgen, OZ7TA

I suggest you wait for it to be optimised before looking for problems in your setup, it is still a beta. Quite brilliant, but not perfected yet. The decoding is about a dB down on the minitiouner with me, but that depends on many factors. Your 2 - 2.5 dB seems rather high. It does depend on the filtering and sample rate, If there is a signal adjacent etc.

Mike

Hello,
Definitely wait before investigating anything.
I had already read about it in a forum, and Simon had promised to look into it.
If I remember correctly, he had already found a solution.

73 Thomas DL5BCA

Mike, Thomas,

Thank you for your responses. I will just wait for next iteration of SDR TV.

Vy 73

Jorgen

Webmaster: You may close the thread.

I use Minitiouner and SDR television; both working with 1m dish; but may be near the limit. I cannot make detailed mesurement.

In the german radio magazine cqdl 202412 the DATV VE RX was described using Raspberry and a SDR stick. I tried this (with modified user interface) but could not receive any video via QO100 (but working "directly").
I was surprised, because I tought, that the reception is defined by dish size and LNB noise mainly, and that there no major difference in the decoding software. But this may be not true.
73
Guenter
DK1RI