I have been traveling several times lately, and other activities have been taking some of the time I could have used for radio activities. This includes a crashed main computer, the one that I used for my radio shack.
This made me do a bit of reorganization. At the moment my shack is run with a Raspberry Pi 4B.
It is slightly under-powered, but will have to do until I get the harddisk in the old machine changed (quite some disassembly necessary).
Now for some radio news:
I have been collecting a large amount of components and modules for my projects, and I think that I am now more or less ready to do some assembly, and where necessary, modifications. The plan and design may change, if necessary. Following some projects in more detail than before.
Project #1: QO 100 "transverter" - more like an indoor unit with TX converter and interrface sircuit for the outdoor LNB:
Circuitry planned:
Common circuits:
a) Local oscillator module for the TX mixer, and possible oscillator for further RX down conversion:
- AD4351 PCB module, controlled by a small Arduino board.
- Two buffer stages, capable of delivering 1968MHz for transmission, converting 432MHz up to 2400MHz, and 595MHz for converting the RX 1st IF (739MHz) down to 144MHz.
b) Circuit for switching to 2.4GHz transmitter mode, including PTT signal for the outdoor PA unit.
c) 25MHz reference frequency generation:
- 25MHz TCXO
- Switch for possible connection to external GPSDO
- Buffers
- possibly output for external devices using 25MHz as reference frequency
2.4GHzTX system:
b) TX mixer/driver stages, module, indoor unit:
- Passive DBM mixer PCB,
- SP5189 PCB
- 2400MHz filter PCB
- SP5189 PCB
- second 2400MHz filter PCB
... if necessary for the stability of the amplifier chain, attenuators can be added between amplifiers and filters, and/or some microwave foam can be added to the inside of the lid for the shielded box.
c) RF2126 module PCB w/heat sink, about 12dB gain, max 1W out. A shielded box may be needed for this.
I will be happy with 300-500mW out of the indoor part, an additional driver (if necessary) and PA should be mounted in a box near the dish feed.
d) Outdoor unit:
- RF2126 module for eliminating cable loss at 2.4GHz
- WiFi "8W" booster module (8 "Chinese Watts" equals 2 - 3W output in real terms), possibly modified for non- antenna output switching.
10GHz RX system:
At the moment a modified PLL LNB with a simple indoor 25MHz reference canned XO is used. The indoor unit and an outdoor system unit are planned:
a) In my indoor unit:
- 25MHz system, see above
- LNB connection with triplexer for DC, LNB IF out, and 25MHz reference to the LNB
- extra IF outputs for the LNB IF output(s)
- Outdoor system with 25MHz reference signal extraction and distribution to the LNB and possible other units, like transverters or other converters.
Construction:
Stage 1:
A main housing has been found, and a fair amount of mechanical work (not my favourite sort of work ;) ) is necessary, mostly drilling holes for connectors in the main housing and in shielded boxes (with shield walls) inside the housing need to be prepared for mounting (internal) connectors and module PCBs.
Further, space for the mechanical work has to be made, some of the tools are present, but a bit more is needed. I will get there
Here is to hoping that it will look,at least, decent when I am finished ;) .
Progress reports and updates with a few pictures will follow.
More projects to follow.
