QO-100 at CN3A

Together with Vasek OK1VVT during CQ WW SSB 2024 on CN3A we talked and thought about what could be done on VHF. Besides future plans with 2m EME I thought about the QO-100 satellite. Since I have been building LNBs for several years, not only for this satellite, it was "just" enough to finish the rest :)

For several years I have been using an Adalm pluto SDR TRX with additional front end boards for VHF remote control (70 MHz, 144 MHz, 433 MHz). So I decided to use this SDR together with a great SDR program - SDR Console. For the RX I used my LNB ext OSC - that is an LNB with the ability to hang a PLL using an external 10 MHz normal. This GPSDO also serves as a reference signal source for the Adalm Pluto. I also found a nice 10W PA in China. I just had to add some more parts like LAN and PoE filters, DC-DC converter with filters and mount it in a box with a heat sink. 

I printed an ice cone feed as an antenna. Outdoor box is connected only with one CAT-5 FTP cable. There is common power supply with LAN filter and PoE injector - all in one enclosure.

LNB: LNB ext OSC MK3

Adalm Pluto: with EXT REF

LAN and PoE filter: with protections LAN PRO-FIL

ICE CONE FEED: web of author

Common 24V power supply with filters

GPSDO board with LNB bias tee, Adalm Pluto PA and DC converters

Testing output power

First test at CN3A without the dish

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The first test on CN3A was done without dish antenna in January 2025. Despite the opposite polarization of the transmitting antenna and simple support of the antenna on an improvised table, it was possible to listen to the beacon. After tuning to the FT8 frequency, I was surprised that I easily decoded several stations. I tried transmitting with 6W RF power into the wrong polarization and it worked :) The first QSO was very easy and thanks to Libor OK1ALX for the test! After the first CQ an avalanche of calling stations came down.

After a month it was time to go again for 14 days of working relaxation on CN3A. Apart from work and CQ WPX SSB I planned to finish the equipment for QO-100, buy a dish and holder and mount everything.

After a couple of days, Jirka OK1RI and I went to get some food and drink supplies and also visited the local “hardware” street in Safi. After an exchange of greetings and a commented (in Czech) demonstration of photos of the antenna on a mobile phone, the seller brought us the antenna and the wall mount. Even a first year engineering student would be ashamed of this mount... but better than nothing :)

After installing and pointing the antenna, the increase in signal strength was significant. The gain was around 30 dB and our own signal is at S9 level. When there is more time, we will sit down to SSB, where it will be much more fun compare to FT8...

All QSOs are confirmed over LOTW.

 10 GHz LNB with external reference / GPSDO

This is the 10 GHz Low Noise Block (LNB) modified for external 25 MHz reference for internal PLL. This signal is feeded by the same one coaxial cable as IF down. Special small Bias Tee box with TCXO or 10 MHz reference signal works as DC injector and also 25 MHz Source for LNB. There is also variable attenuator for IF signal which allows you to change IF signal from 0 to maximum. You can still switch between V and H polarisation by supply voltage.

More at: https://remoteqth.com/lnb_gps.php

Main functions:

• Ku band LNB
• Very low noise converter
• External 25MHz PLL reference signal over IF coax cable
• LO = 9750 MHz: 10489 - 9750 = 739 MHz IF etc
• V + H pol
• Supply over one coax
• Voltage supply +12V for V-pol, +15V for H-pol


• Bias Tee board
• DC supply over one coax together with 25 MHz PLL reference signal
• Build in TCXO with 0,2 ppm as alternative to 10 MHz reference input More in WiKi
• 10 MHz reference input for very big frequency precision and stability
• LO = 9750 MHz: 10489 - 9750 = 739 MHz IF etc
• Variable ATTENUATOR in the bias tee
• High voltage / current protection
• Voltage supply +12V for V-pol, +15V for H-pol More in WiKi
• Bias tee connectors: IN (LNB) = F, OUT = SMA


• Option: 10 MHz PLL-GPSDO reference source
• 10 MHz reference source locked to GPS signal More in WiKi
• RF output typ + 5 dBm
• HW by BG7TBL, modification by OK2ZAW
• Including GPS antenna and DC cable
• Including coax cable with BNC and SMA (abt 50cm)


• Option: 3D printed adapter for POTY dual band antenna
• UV stable PETG material
• 22 mm Cu tube diameter
• ONLY ADAPTER, not 2.4 GHz antenna!


• Option: 2-way small splitter box
• Small splitter for 10 MHz reference signal
• Splits 10 MHz signal to Bias Tee box and another your device (SDR, TX etc) More in WiKi
• Low loss 3,5 dB
• Including coax cable with SMA


• Option: RTL-SDR receiver with 1ppm TCXO
• RTL-SDR USB receiver
• In metal box
• 1 ppm TCXO for better stability
• Input SMA connector
• SMA - SMA cable included (17 cm)
• Firmware already installed
• 8 bit, up to 2 MHz of spectrum
• compatible with: HDSDR, SDR console etc.

Technical parameters:

LNB local oscillator:				9750 MHz (with 25MHz source)
Conversion gain of a LNB:			> 50 dB
LNB IF:						739 MHz for 10 489 MHz (QO-100), 618 MHz for 10 368 MHz
Reference 10 MHz input power:			- 3 dBm to + 13 dBm
Stability with 10 MHz reference:		depends on reference source
Stability with 25 MHz TCXO (0,2 ppm):		0,2 ppm (X 390)
25 MHz cut off to RX output port:		> 50 dB
Frequency error with TCXO:			max. 3 KHz, typ. less than 1 kHz (after 5 minutes) 
DC power:		       			+12 V for Vertical polarisation - NB and  +15 V for Horizontal
Bias Tee IF loss:				typ. less than 2 dB
Variable Attenuator on IF:			0 dB to NO signal

⚠ NOTE: This Bias Tee box is designed for 10 MHz external reference source but you can also use internal 25 MHz TCXO, which is 0,2 ppm. Frequency error is max. 3 kHz.

Schematic for version 0.3

PCB for version 0.3

Duplexer 25 MHz and High pass filter for IF + ATT

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Optional GPSDO PLL

Internal TCXO or 10 MHz external reference source

POTY antenna adapter for 22 mm Cu pipe

10 GHz LNB with PLL and TCXO, Bias Tee, part II.

   Very simply modification of LNB with PLL and 25 MHz X-tal. With 1 ppm TCXO there is nice 10 GHz RX for tropo and satellite. You need only some SDR receiver.

NEW VERSION ALSO WITH EXTERNAL REFERENCE: HERE

 

New version

With Poty adapter 

   Bias tee board allows you to supply LNB over the coax. It also includes high current and voltage protections as well the variable ATT. You can easily set "gain" of LNB as you need. Recommended power supply is +12 V and some 100 mA.

More info about TCXO modification is there...

You can ask for price on my email: honza at ok2zaw.com or Order page 

Do not forget to visit our OpenWeb RX on 10 GHz:

http://eshail.ok2zaw.com:8073/

http://server.ol7m.com:8873

Es Hail 2 - Oscar 100 satellite OpenWeb RX

It looks that new Es Hail 2 - Oscar 100 Satellite will be very popular. Big advantage is that this is the geostationary satellite! You can fine more here. It has got 10GHz down link. Well, years ago it could be a problem, but now you can buy cheap LNB for very small money! You can use TCXO for better stability and very simply RX is done (it is link)!

And LNB with external reference: https://ok2zaw.blogspot.com/2020/08/lnb-10ghz-with-external-reference-gpsdo.html

After 10GHz tropo OpenWeb RX I made also Es Hail 2 one:

http://eshail.ok2zaw.com:8073/

 RTL-SDR for Es Hail 2 and another 2 RX for tropo 10GHz and 2m APRS:

 Future of 2,4GHz Uplink