NEW version: 10 GHz LNB EXT OSC MK3
This new Bias Tee Box MK3 offers two LNB reference signal options. The first is an internal (very accurate and stable) TCXO - this can be used if you cannot connect an external 10MHz source. If you do have an external 10MHz precision signal source - e.g. GPSDO - this will give you an accurate and stable reference signal for the PLL in the LNB. The reference signal is sent to the LNB together with the IF signal from the LNB via a coaxial cable. In this MK3 version, the reference signal is multi-filtered by quartz filters, ensuring both signal purity and reduction of possible harmonic components. The result is a much cleaner IF signal and noticeably better PLL phase noise (compared to the previous version or the competition), even when using a lower quality 10MHz reference source (GPSDO). This is particularly beneficial for weak signals at and below the noise floor - EME. A specially designed diplexer in the Bias Tee box separates the reference signal (25MHz) from the IF signal ( > 600MHz) and the DC power supply to the LNB. The LNB power supply still guarantees polarization switching capability and switching to H-pol is indicated by a front panel LED (supply voltage above 18V). The power supply is protected by a special electronic fuse that protects the box in the event of a short circuit in the coaxial cable. The input from the LNB also has HV protection by gas discharge tube and antiparallel diodes. The IF signal from the LNB passes through the frequency and power diplexer to the variable attenuator. This allows the conversion gain of the LNB to be adjusted to avoid overdriving the RX. In this MK3 version, the ATT trimmer is positioned so that the gain can be conveniently adjusted on the front panel of the box. The RX output is again protected by diodes, and there is a super-fuse that will disconnect the unit if there is a strong signal on the RX port - a signal from an incorrectly connected TX and levels above 20mW - protecting the box and LNB from destruction. The main difference from the older version is the filtering of the 25MHz reference signal. X-tal filters are used to achieve the best possible filtering. One before the buffer amplifier and one after it. Another one is directly in the LNB. Thanks to this filtering, better phase noise and signal clarity is achieved even with a worse 10MHz signal source.
OLDer version: 10 GHz LNB + Bias Tee with TCXO or 10 MHz reference input (9750 MHz LO) for GPSDO - QO-100 and tropo
This is the Ku band 10 GHz LNB (Low Noise Block) with external reference input. LNB needs 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 (25 MHz) or 10 MHz reference signal (GPSDO) works as DC injector and also 25 MHz source for the LNB. There is also variable attenuator for IF signal which allows you to change IF signal from 0 to maximum. High Pass Filter and 25 MHz Notch Filter at IF line. You can still switch between V and H polarisation by the supply voltage. You can use it for QO-100 satellite and also for Tropo contesting / DXing.
Main functions:
- Ku band LNB
- Very low noise converter block
- 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 BOX
- DC supply over one coax together with 25 MHz PLL reference signal
- ONLY for LNB with 25 MHz PLL reference input
- Build in TCXO with 0,2 ppm as alternative to 10 MHz reference input More in WiKi
- 10 MHz reference input for very bhigh frequency precision and stability
- LO = 9750 MHz: 10489 - 9750 = 739 MHz IF etc
- High Pass Filter in IF RF line
- 25 MHz Notch Filter at RX output - version MK2
- 10 MHz input simply X-tal filter - version MK2
- Variable ATTENUATOR in the bias tee box
- 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, 10 MHz ref IN = 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 (TROPO/EME) 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 - WB Bias Tee IF loss: typ. less than 3.5 dB (filter + notch + ATT) Variable Attenuator on IF: 1 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.
⚠ NOTE: Do not forget that the quality of the 10 MHz signal source has got final effect on the quality of the output signal. With added phase noise multiplying by PLL.
Block diagram of the Bias Tee BOX:
Measurements:
Variants:
- LNB with external 25 MHz source over IF coax cable
- Bias tee box 25 MHz source
- LNB & Bias tee box 25 MHz source Photo
- LNB & Bias tee box 25 MHz source & RTL-SDR with SMA-SMA cable (15cm) Photo
- LNB & Bias tee box 25 MHz source & GPSDO 10 MHz reference with cable Photo Cable
- LNB & Bias tee box 25 MHz source & RTL-SDR & GPSDO 10 MHz reference with cables Photo Cable
- LNB & Bias tee box 25 MHz source & GPSDO 10 MHz reference & 2-way splitter box with cables Photo
- LNB & Bias tee box 25 MHz source & RTL-SDR & GPSDO 10 MHz reference & 2-way splitter box with cables Photo Cable
- LNB can be classic or with POTY adapter Photo
Set Includes:
- Ku band LNB with EXT PLL source
- Bias Tee BOX - assembled
- Option: RTL-SDR + SMA-SMA cable (15cm)
- Option: GPSDO PLL 10 MHz source + BNC-SMA cable (50cm)
- Option: 2-way small splitter box + SMA-SMA cable (15cm)
- Option: 3D printed (PETG material) POTY antenna adapter (22mm)
- POTY - ONLY ADAPTER, not 2.4 GHz antenna!
Download
LNB Bias Tee BOX with TCXO / 10 MHz reference input | |||||
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MKII. rev 1.2 | sch | pcb | Files275 | MANUAL MKII | |
rev 0.3 | sch | pcb | Files275 | MANUAL ver 0.x | |
3D printed POTY adapter STL file | |||||
rev 0.1 11-2019 | picture | Files713 | |||
We believe open source is a better way of doing things. View and download the Shield Schematic and PCB Kicad/Eagle CAD files, LibreCAD .DXF, or Inkscape .SVG files. The hardware designs are released under the Attribution-NonCommercial 2.0 Generic |