OK2ZAW - OL9A - OK4ZAW QRO.CZ blog

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