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

I

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

10GHz LNB with PLL and TCXO

   Satellite LNB is very cheap source of 10GHz converter. Especially now, when the classic DRO was replaced by the PLL with X-tal. I played with 10GHz tropo web SDR RX. It works great. There are two LNBs with one TCXO. You can see more here. As IF RX there is nice RTL-SDR toy. I do have TCXO for that as well and done some modification for better stability. You can find more here. 

NOW ALSO NEW VERSION WITH EXTERNAL SOURCE / 10 MHz GPSDO: HERE LINK

   There are two (?) X-tal frequencies in the LNB. I do have one with 25MHz but I have seen one also with 27MHz.  LNB with the original X-tal can be 100kHz shifted. After heating it is stable, but not as well as with TCXO. There is standart X-tal so you need to use some SDR for the IF frequency. 

For example, the 25MHz is multiplied by 390 to 9750MHz. If you calc IF then it is:

10 368MHz - 9750MHz = 618MHz

For Es Hail 2 it is:

10 489MHz - 9750MHz = 739MHz

I ordered also another two TCXOs for 70cm IF. Than:

10 386MHz to 432MHz is 25,476923MHz

10 489MHz to 432MHz is 25,787179MHz

But I ordered 1ppm TCXO, so there is some mistake done by the production:

 

This is not a problem for SDR RX where you can do some calibration. But for classic 70cm RX you do have some frequency offset mistake :( 

Do not forger, any small mistake is multiplied by 390 !!! So 10Hz is finally 3,9kHz !

Almost right frequency

21Hz mistake means 8kHz on IF (RF)

Rebuilding the LNB. There is a lot of different LNBs... In my one I remove original X-tal and add TCXO. There is close V-stab what is and is not good. It is easy to connect power supply to TCXO on the other hand, this stabiliser produces heat... There are more ways, I used 1k8 resistor from 6V to TCXO. It is 3V3 one. Or you can use 3V3 zener diode and 680 ohm resistor. Do not forget to 100nF capacitor or more.

With zener diode

TCXO description

Voltage bias tee. There is a PCB designed to do voltage supply bias to LNB over the coax, with some protections and also variable ATT. LNB + RTL-SDR can have too high gain, so you can set it as high as you need!

 I can offer you TCXO, rebuilded LNB and bias tee. If you are interested, please contact me at:

honza at ok2zaw . com

Please try our Es Hail 2 - Oscar 100 Open web RX :)

HW at OL7M for OpenWEB RX

Links:

Es Hail 2 WEB SDR !!!

OK1UFC LNB info

OK2ZAW-OL7M 10GHz tropo RX

10GHz OpenWEB RX at OL7M QTH

During the playing with RTL-SDR I have decided to try 10GHz OpenWEB SDR at OL7M. There are very nice and cheap LNB converters with PLL and 25 MHz X-tal. I found cheap TXCO in China for a few USD. So this was really nice way to start building stable and cheap 10 GHz converter for the RTL-SDR. And what more, split two LNBs to two directions. It means 3 dB more noise, but why not. 

We do have new tall tower which has got nice view in 360 deg. First LNB looks to N-W and second one to South. There are easy copy OK0EA and SR6XHZ and during RS conditions also OE beacons.

And easy modification for cheap RTL-SDR with new TCXO: HERE

http://server.ol7m.com:8873

OE beacons during RS

LNB directions

The TOP of the TWR with 2m APRS antenna.

LNBs in box

 PC and RTL-SDR in USB HUB.

RTL-SDR dongle with new TCXO oscillator

RTL-SDR (RTL2832) is very cheap TV dongle than can be used as PC based scanner. You can use it for various applications as: HF/VHF/UHF SDR receiver, waterfall for your TRX (IF), APRS Igate, ADS-B Aircraft radar etc.

Dongles use classic 28.8 MHz crystal oscillator. With original one the frequency stability and error is quite poor. Frequency mistake is around 15 kHz on 900 MHz...

That is why I decided to try to exchange original oscillator for the NEW 28.8 MHz TCXO with 0,5ppm. There are some pictures of the modification.

TCXO informations

Frequency offset with original crystal oscillator:

And with NEW TCXO installed!

Remove original crystal

Clean piece of GND on PCB and solder TCXO.

Be careful! Do not connect top of the TCXO with the ground!!!

Cu wire from crystal pad to TCXO one.

Cu wire from Vcc to the TCXO with additional capacitor.

Or another possibility:

Example of application of RTL-SDR with great open sw OpenWEB RX:

- 10 GHz SDR RX with SAT LNBs with TXCO :)