High stability 10GHz LNB. 
PARI-O (Power And Reference Inserter - OCXO) 

The PARI-O consists of a modified 10GHz LNB for outdoor use and an indoor unit that feeds power and reference signals to it and extract IF signal for use by an external receiver. 
This forms a high stability low phase noise 10Ghz down converter unit that can be used for any 10GHz reception in general and for Oscar 100 satellite reception in particular.  



  • Size: 290x305x33 millimeter

  • Power usage: 10W Max, 3W typical.  (12V 600mA at startup, 250mA after one minute of warm-up)

  • Weight: 222 gram

  • Frequency accuracy: better than 10 ppb - typically 2 ppb*

  • Frequency drift at 10GHz due to temperature variation is typically less than 2Hz.  

  • Calibrated against in-house Rubidium standard before delivery.

  • Comes delivered with modified commercial 10GHz LNB and power supply.

  • Single 75ohm coax between LNB and indoor unit.

  • Can be frequency re-calibrated by user if needed 

* ppb=parts-per-billion



The PARI-O (Power And Reference Inserter - Ovenized crystal oscillator) is a Low Noise Block amplifier/Down-converter for Oscar 100 reception.

The LNB is a commercial unit that has been modified to make it's internal local oscillator highly frequency stable as needed for Single Side Band reception on the 10GHz band.

This product is primarily intended to be used for Oscar 100 satellite reception but can be used to down-convert the entire GHz amateur band - however - the sensitivity goes down with frequency.

It has the highest sensitive on the band edge around 10.5GHz were the Oscar 100 is being operated.

The Local Oscillator in the LNB operates at 9.750MHz so use the formula - Input frequency minus 9,75 GHz to calculate the IF frequency.

When receiving the narrow band transponder from the Oscar 100 satellite the IF frequency will be 739.5MHz to 739.9MHz 

This can be processed by a converter/transverter or sent to a SDR receiver to receive the SSB signals from the satellite transponder.

The product consist of three units.

1 The LNB/10GHz down-converter.

2 The indoor unit that connects to the LNB and extracts IF signal.

3 A power supply that feeds the two units.

The reference signal for the LNB is being feed up to it in the same coax cable that it is using for power and IF signals.

The reference signal is being generated by a high quality Japan made OCXO inside the indoor unit
The result is a very low noise and stable down-converter with virtually no frequency drift.


The indoor units also has three 10MHz reference outputs so external units can use the very stable and accurate reference signal from the OCXO to lock a transverters or to generate a stable transmitting signal.


The OCXO in the indoor unit is calibrated by my in-house Rubidium clock before delivery.

It typically is accurate down to around 2 parts per billion, this means that on 10GHz will be off in frequency more than 20Hertz.

The drift due to temperature changes is a magnitude lower than this, typically the short term temperature drift is less than 2Hz at 10GHz.

The low drift is partly due to having the reference oscillator indoors and being feed remotely and partly because of the high quality OCXO.


The unit is ready to be put on the air and the user only needs to connect the two units with standard 75ohms coax and connect the receiver or SDR to the IF output.


The indoor unit can be desk or wall mounted.

The power supply included is a 12V power supply with a Euro plug but the unit can accept 8 to 20V on it's DC input.

This makes it possible to switch LNB receive polarization electrically.

Receive polarization change occurs when the LNB voltage goes above 17V.

Minimum voltage is 8V - the LNB stops working at this voltage.

Maximum voltage is 20V - the heat dissipation of the unit will be excessive if going above 20V, permanent damage to the LNB happens somewhere above 22V.

Power consumption is around 600mA at warm up going down to around 250mA after the OCXO has warmed up.

Warm up takes about 1 minute to reach the  lower current consumption but please allow five to ten minutes of temperature stabilization after first turning on the unit.

Connectors of the indoor unit.

The internals of the Indoor unit

The picture shows how to hock-up the unit.

Screenshot of the narrow band transponder as viewed by a SDR connected to the IF output. The Antenna is a 80cm parabolic reflector in South Sweden. The lower beacon is exactly at 739.550MHz due to the exact frequency of local oscillator in the LNB

© by ZachTek.