OK2ZAW - OL9A - OK4ZAW QRO.CZ blog: July 2021

NEW parts from my QRO.cz:

There are some new parts which I made in last month. I do have much more at the table, but I am waiting for enclosures...

Small 3-way RX splitter / combiner board:

The splitter or combiner is a very useful device. It can provide equal voltages, equal current, or equal power to matched or unmatched loads. Like all passive splitters and combiners, this device is less than ideal. Isolation is maximum only when at least one port are properly terminated. In this case isolation between the three splitted/combinated ports is maximum when the main port is properly terminated. This HW is designed only for RX line. Both impedances 50 or 75 Ohm can be selected by the jumper.

Main functions:

- Broadband: 0.1 MHz to 60 MHz

- 3-way Splitter or Combiner

- Low loss

- In to Out is typ. -5,8 dB

- 50/75 ohm impedance - easy jumper switch

PCB size = 50 x 50,4.

Aluminium enclosure size W x H x L = 58 x 24 x 50.

Parameters:

- Impedance 50 or 75 Ohm

- Insert loss: around 1 dB

- Split 4,8 dB, together with IL around 5,8 dB

- Isolation more than 18 dB for middle port and more than 23 dB for 1 and 3

- SWR on splitted ports better than 1:1,15 on HF, resp. 1:1,25 on 6 m

- SWR on main port around 1:1,3 on HF, resp. 1:1,4 on 6 m

Use:

- Antennas combiner - 3 el broad side array

- RX signal divider

- 10 MHz signal splitter

- One antenna to three RX

More at: RemoteQTH.com web

4-way PTT splitter:

This is simply 4-way analog splitter. Designed for no-delay PTT switching. From one input to 4 outputs. You can split PTT signal to 4 independent devices.

Main functions:

- Universal (PTT) switch splitter

- Minimal delay

- Compatible with 5V PTT logic (OM-power)

- 4 x output FET switch - DC 50V 0,5A

- PTT LED indicator.

- RCA connectors.

- PCB size = 50 x 50,4 mm.

Available as:

Assembled board - tested

Assembled in aluminium enclosure (blue)

Parameters:

- Input PTT logic compatible with 5V and more

- Input PTT logic active when grounded

- Input PTT logic current typ. 40mA

- Output FET switch 50V 500mA for each port

- DC power supply 9V to 15V typ. 65mA

Use:

- PTT for more PA

- TRX PTT to another RX and TX devices

- PTT to interlock, PA etc.

More at: RemoteQTH.com web

Decoder BCD to DEC (1 from 8) not only for antenna switch:

This is simply but powerful decoder from BCD data to one of eight. You can use it everywhere you have less wires than you need. You need only 4 wires and control up to 8 outputs. You can supply external relays over the BCD data wires. There is universal output driver. You can drive outputs by switching to GND or + Vcc voltage. BCD inputs include RF and high voltage protection.

Main functions:

- BCD to DEC matrix table

- Outputs 0 to 7 or 1 to 8 (jumper)

- Universal OUTPUT: + or gnd

- No external voltage needed. Up to 0,5 A by BCD wires

- BCD input 9 to 13,8V

- RF and high voltage protections

- Both drivers (ULN and TBD) are included

- PCB size = 90 x 52

Parameters:

- Output current max. 500mA

- Voltage drop for TBD driver typ. 0,2V for +12V input and 0,6V for BCD wires power input