IQmonitor tool

femi

Sorry for my indecently short answer - there was not enough time and effort, plus the power was turned off when I almost finished translating my article:

IQmonitor Pro program - operation in extended search range mode

I debugged the IQmonitor Pro program mode - work with an extended search range.

This mode is due to the use of the third harmonic of the local oscillator of the PCI card tuner

allows you to expand the range of actually received signals up to theoretically 7.5 GHz

and up to 1.9 GHz practically.

First, let's see how it works on the example of the 0.8°W position - double-click on

peak of the transponder, which is at a frequency below the lower limit of the upper Ku subband:

At 11297 MHz (253 MHz below the lower frequency of the Ku high subband) 2.5dB below the lock threshold

a signal with SR=30000 kC/sec, FEC 3/4 and 8PSK modulation was registered. Moreover, occupied by him in fact

the bandwidth is exactly three times the width of the transponder peak in the spectrum.

This is a direct indication that the signal is received at the third harmonic of the local oscillator. Therefore, we turn on the mode

advanced search by checking the Expand search band checkbox

Now in the hint near the cursor, in addition to the frequency at its position, a second line has appeared, which indicates

frequency of the transponder that can be received at the third harmonic of the local oscillator by double-clicking on the spectrum:

As you can see, this frequency is 1.4 GHz higher and lies on the upper edge of the Ku high subband.

Let's try to find this transponder there:

As you can see, we have successfully locked this transponder at the "true" frequency at the first harmonic of the local oscillator.

Moreover, with a large margin for lock - after all, the amplitude of the first harmonic of the local oscillator is significantly higher than the amplitude of its third harmonic.

If you spare your time and scroll through my blog in the opposite direction, you will find a picture,

which confirms the reception of a television image not only on the third, but on an even weaker

FIFTH! ! ! harmonics of the local oscillator.

And now look at an example of using the OMICOM budget card, which, according to the passport, cannot

accept transponders with a center frequency greater than 12750 MHz and symbol rates less

1000 kS/s, for receiving an ultra-low-speed transponder at the frequency of the new, extended Ku

range:

Don't let the headline fool you - before experimenting with the Turksat 5A, I watched the news on

Firebird and just forgot to change the name of the satellite when the USALS system turned the antenna with the aperture

1.05m at 30.9°E.

It is easy to see that on the usual RF spectrum in the Ku band, the transponder is barely distinguishable

hump with an amplitude of ~1 dBm. I would never have paid attention to him, but on the spectrum of high

resolution with a frequency step of 124 kHz, the IQmonitor Pro program singled out the peak with one spectral line

amplitude of 5.5 dB, which is perfectly confirmed by the transponder tuning time curve.

In the advanced search mode, a signal was successfully found at a frequency higher than 1.9 GHz, which occupies

band three times the frequency step of the HR spectrum, that is, a transponder from the new range with a frequency

13424 MHz was received through the third harmonic at 11541 MHz!

The IQmonitor Pro program made it possible to improve the performance of the budget card twice in terms of frequency and four times in terms of

symbol rate. In fairness, I must say that the OMICOM card was tuned by me -

screens, a fan were added, and the supply voltage ripple, which reached 21 mV, was smoothed out

three electrolytic capacitors. But the main merit still belongs to the IQmonitor Pro program.

Filatov Yuri

June 2nd, 2021

IQmonitor Pro - range of available RF frequencies

Yesterday I experimented with the availability of RF frequencies in IQmonitor Pro.

For the TBS 6983 card with the STV6120 tuner, the available range of 250 - 2500 MHz is confirmed,

but for the OMICOM card with the STV6110 tuner, the RF range available for the program

extended to 620 - 2500 MHz.

Moreover, for intermediate frequencies above 2150 MHz and below 950 MHz, there is a significant

blockage of the gain (CG) by about 5-7 dB:

Such a decrease in CG does not affect the performance of the program algorithms and allows you to expand

reception range up to 350 MHz and down to 330 - 700 MHz. This is especially important in the Ka band, where

using LNB C subband, for example, you can receive signals B and D frequency subbands.

In addition, the possibility of significantly expanding the reception range through the use of

third harmonic of the local oscillator.

Here is an example of reception on the first (main) harmonic of the local oscillator:

And the same transponder is accepted on the third harmonic of the local oscillator (when the program is tuned to a frequency that

below the actual transmission frequency at 1333 MHz) :

To support the possibility of receiving at the third harmonic of the local oscillator, IQmonitor Pro will add

reception prediction mode far outside the usable intermediate frequency (RF) band

_________________________________________________________________________________________

PS This mode added to the IQmonitor Pro program

Filatov Yuri

May 31st, 2020

IQmonitor - fantastic features!

Today I checked the ability of the local oscillator of the STV6120 tuner to operate in the range of 250-2450 MHz.

I was convinced of this when receiving a 13°E satellite with a LNB local oscillator frequency of 9750 MHz using the IQmonitor program.

Yes, it works, and above 2150 MHz there is a sharp decrease in the amplitude of oscillations of the local oscillator -10 dB / 300 MHz.

At the same time, the SNR of the signals, which was determined by blind search in high-resolution mode, remains at the level of 11-12dB, which confirms precisely the decrease in the Lo level, and not the RF level.

In the lower part of the spectrum, a number of transponders are blocked, the width of which is approximately three times the width of the spectral peaks, which is not normal.

For verification, the transponder was locked at a frequency of 10372 MHz.

After receiving the transport stream and parsing it with the TSReader program, it turned out that this is a 11623 MHz transponder signal.

It was at this frequency that the local oscillator frequency was corrected and a second frequency lock of 10372 MHz was carried out.

Calculations showed that this signal was locked at the third harmonic of the Lo frequency, the amplitude of which is only 3.4 dB less than the first harmonic.

Please note that at the very beginning of the spectrum at a frequency of 10007 MHz, a transponder with SR = 27500 kS/s is locked, the peak width of which is 5 times! narrower than the bandwidth occupied by a signal with such a symbol rate !

After receiving the transport stream and parsing it, it turned out that this is a signal from a 11034 MHz transponder:

Calculations showed that the intermediate frequency is exactly 5 times less than that of the transponder local oscillator locked at the first harmonic:

Thus, it has been proven that the TBS6983 card, together with the IQmonitor program, is capable of receiving signals at the 3rd and 5th harmonics of the STV6120 tuner's local oscillator.

This fact means that it is possible to receive transponders whose frequency differs by 7350 {12250} MHz from the local oscillator frequency of your LNB !!!

This experiment shows that with the help of the IQmonitor program, you can significantly expand the capabilities of your receiving equipment,

for example, to receive several Ka subbands with one LNB, or try to receive X-band signals with a C-band converter.

Zitat von femi

Hallo Yuri,

flo1 = flo2 war eigentlich genau das, was ich wissen wollte.

Ich hatte eine Anfrage, das Ka-band betreffend, und wollte ehe ich den Mund aufmache, einige Versuche starten.

Stephan hat hier bereits mit der Version 2.4.0.5 experimentiert, was nicht spurlos an mir vorüber ging.

Nachdem nicht weiter nachgefragt wurde, widme ich mich vorerste dem Anfertigen eines T-Hohlleiters für das Ka-Band.

Im schlimmsten Fall war es eine Übung mit der Fräsmaschine.

Abschließend noch eine großes extra DANKE für die ausführliche Beschreibung.

Hello Yuri,

flo1 = flo2 was actually exactly what I wanted to know.

I had an inquiry regarding the Ka-band and before I opened my mouth I wanted to do a few tests.

Stephan has already experimented here with version 2.4.0.5, which left its mark on me.

Since no further inquiries were made, I dedicate myself to making a T-waveguide for the Ka-band.

In the worst case, it was an exercise with the milling machine.

Finally, a big extra THANK YOU for the detailed description.

Привет Юрий,

flo1 = flo2 было именно то, что я хотел знать.

У меня был вопрос относительно Ка-диапазона, и прежде чем я открыл рот, я хотел провести несколько тестов.

Стефан уже экспериментировал здесь с версией 2.4.0.5, которая не оставила на мне следа.

Поскольку никаких дополнительных запросов не было, я посвящаю себя изготовлению Т-волновода для Ка-диапазона.

В худшем случае это были упражнения с фрезерным станком.

В заключение большое СПАСИБО за подробное описание.

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The last translation of the articles, which concerns the expansion of the reception range, including the Ka subbands.

And then I would like to know the details of the project, which involves the manufacture of a T - shaped waveguide.

Filatov Yuri

June 11th, 2020

IQmonitor - reception beyond the possible

Everyone is well aware that receiving equipment (LNB and PCI cards) have a limited operating range.

The boundaries of this range are usually indicated on the device or can be found in the technical documentation.

The width of the operating range depends primarily on the frequency overlap of the local oscillator

and, to a lesser extent, from the bandwidth of the receiving path.

This band is normalized, as a rule, at the level of -3dB. The narrower the reception band, the lower the level

noise, so hardware developers tend to create narrow-band bandpass filters

with great steep slopes.

The LNB shown in the photo has an operating range of 21.2 - 22.2 GHz, that is, the bandwidth

1 GHz with a center frequency of 21.7 GHz is only 4.6%.

To cover the entire Ka band, you have to use up to 4 LNBs or LNBs, in which

up to 8 local oscillators are switched.

My friend stephan94 did a brilliant experiment on receiving outside of work

range of the LNB, but, due to natural modesty, does not publish its results.

And I, as a friend who is not a hindrance to modesty, will present you these unique data:

Above the red line in the table of locked transponders, you can see four transponders that @stephan94

outlined with colored frames for identification with four of the same transponders, but accepted within

operating range LNB on the main (1st) harmonic of the local oscillator of the tuner STV-6120, which is installed in the PCI

card TBS-6983.

stephan94 carried out a full-fledged reception of transponders at frequencies that are 860 - 900 MHz lower than the true

transponder center frequencies !

But the most fantastic thing about these results is that the 21538 H signal received at the harmonics has an SNR of 3.2dB

higher than the same signal in the working frequency band !!!

My friend's success inspired me to create a special mode for searching for DVB-S2 signals OUTSIDE

operating range of the LNB.

This mode is turned on simply - you need to check the checkbox Expand RX band :

After that, when the cursor moves over the spectrum tablet, in addition to the current signal frequency (10178 MHz) and its level (-46.9 dBm)

under the current frequency, the predicted frequency of the same signal from the satellite appears, but received at the 1st harmonic

tuner local oscillator STV-6120 (11034 MHz). It is easy to see that the signal level at the first harmonic is -33.0 dBm,

which is 13.9 dBm higher.

Another useful feature of the IQmonitor 2404 program is the presence of a PoP menu that allows you to lock

transponder and get comprehensive information about it in one click on Tune to Frequency:

Before this (which is optional) the Feed Report PoP menu option was enabled, which showed MERa=11.47dB at SNR=10.2dB.

As a result, we have a confident reception of the 11034 MHz transponder at a frequency of 10178 MHz:

This result is confirmed by the TSReader program integrated into IQmonitor:

I would like to take this opportunity to once again thank @stephan94 for his fruitful contribution to the improvement of the IQmonitor program

Yesterday I tested a new IQmonitor Pro option - automatic correction of the designed reception range depending on the actual reception range at the intermediate (RF) frequency. At the same time, I once again checked the correctness of the advanced search option for frequencies that can be received on the 3rd harmonic of the internal local oscillator.

Once again proved that the range of intermediate frequencies for TBS-6983 extends from 250 to 2500 MHz:

I got a result that clearly shows how in-band interference with a power of 22dBm through the AGC system completely suppresses signals from the satellite at adjacent frequencies.

For comparison, I cite the spectra obtained earlier (see the time and date of registration) obtained from the same antenna.

Apparently, the time has come to raise the archival topic of studying noise and interference to SAT reception, as well as methods of dealing with them.

Zitat von flie

Had to tray with NS3/4 Feed-reports again

may be 11387V is active now ?!

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Please explain to us how these three constellations were obtained, which clearly show dark colored graticule lines that do not line up with the light dotted graticule lines outside the constellation.

I ask you to give the most detailed explanations of the appearance of these artifacts.

Thanks.