MY QO100 SETUP

Hi,

Measuring SNR of 90 cm offset dish with Octagon twin LNB with latest modification at SDR-Console and a PLUTO.

Hi,

This 35 dBm (3W) 19 dB power amplifier for 2.5-2.7 GHz works down to 2.4 GHz. The problem was that it works from -12V to -28V. It was modified for +15V operation. A DIP MC34063 was used to invert the +15V to about -8V. As the space was limited and even the Chinese PCBs do not fit, a spider construction was successfully used. Some online MC34063 calculators was used.

Hi,

Using WSL in Windows 10, Ubuntu 18.04 & 20.04 is running all together, permitting two GNURadio 3.7 & 3.8 (one in 18.04 and the other at 20.04) to run at the same Pluto at the same time.

Hi,

A OCXO based 10 MHz oscillator is built around the OSC5A2B02. A 7805 provide 5V to OCXO and to a 4.096 V precision regulator for the trimmer that tunes the OCXO. A 74LS04 buffers the output and drives one more inverter giving TTL output and two pairs of inverters drive two LPF that produce two +20 dBm sine outputs with harmonics 40 dB lower.

The result is a signal that has a +-15 Hz jitter at 10 GHz. It is close to final frequency after about 5 min.

Quote from PA3FYM

What 4.096V regulator did you use, LM4040D41ILP ?

MCP 1541 TO92.

Also series first LPF (T not Π).

2.320 GHz W1GHZ transverter

Specifications

Frequency range : 2320-2322 MHz

IF : 144-146 MHz

Power input : 1 Watt

PTT : external input

Frequency reference : 10 MHz external

Receiving sensitivity : -125 dBm / 12 dB SNR

Power output : 1 Watt (CN0417)

SWR protection : full (circulator)

Tx image rejection : -40 dB

Harmonics rejection : -50 dB

Power voltage : 9-13.8 V

Rx current : 150 mA (@12V)

Tx current : 1A (@12V)

Dimensions : 250*160*55 mm

Hi,

For portable operation a 13.8V power bank using 4*2 surplus matched 18650 is used.

Specs:

13.8V, 3A max (limited) output.

5 hours @ 500 mA discharge time.

V&A meters @ battery.

Charging current 1.5 A (750 mA for each 18650)

Charging input voltage 4-30V.

LEDs charging indication

Anderson 30A output connector.

S4 Lithium protection unit.

Teflon cables.

Electronic 3A fuse at charging input.

Dimensions : 150*110*50 mm.

Weight : 820 gr

Update: a non plastic material, heat resistant, replace the white plastic 18650 insulation separator .

Hi,

Frequency hopping tests begin at WB between 10.492.750 - 10.494.750 according to previous guidelines. FreeDV 1600 is used with GNURadio. A 80 cm dish with 3 Watt and Pluto is used. The hopping is not random, is saw-tooth. The photo is from one hop per second with 300-400 KHz spread bandwidth. Maximum frequency hopping bandwidth of 500 KHz can be archived. Recovering the signal is done now manually, using variable delay. Rename the mp3.txt to mp3 to listen to it.

Hi,

10.000 hop per second with 150 KHz bandwidth archived.

Rename the mp3.txt to mp3.

Hi,

Just another Pluto with Ethernet, Rev D now, in a more compact box.

Hi,

10 MHz OCXO, 74HC74 dividing by 2, xtal filter selecting 5th harmonic (25 MHz), MAV11, splitter driving Pluto and one more MAV11 driving LNB.

Hi,

Portable station just before putting into the box.

Hi,

Thanks DO4FB & DK2TX for QSO with portable NB station.

Hi Gerhard OE3GBB,

In practice what is important is the degradation in performance. I have to use as much power as I can. I use the WB transponder in the 1st section. I have noticed that degradation exists when others use the WB transponder. I continusly change flowgraphs experimenting. I must try USB modulation as it will permit me to hear the difference and not just degradate the FreeDV performance that I have now.

QO100 opened a wonderful window of experimtation in high frequencies and digital communications!!!

Quote from SV1BDS

Hi,

10.000 hop per second with 150 KHz bandwidth archived.

Rename the mp3.txt to mp3.

In practice is 10.000 sweep per second!!!...

Quote from OE3GBB

Hi George,

This is off topic, but you are very experienced in GNU-Radio:
Do you know of a ready to use model in GNU-Radio for testing a simple RX/TX repeater using a Pluto or LimeSDR? Could be NBFM or linear.

Want to try 23cm or above.

73 Gerhard

Can you explain what exactly you want to do?