24 GHz transverter II

1. Offset dish and tripod with pan/tilt mount

Same design as for my 76 GHz transverter and pan/tilt head.

2. W2IMU dual mode feed horn

Slightly modified new version for better receive performance: f/D = 0.71
It is a circular wave guide with a diameter of 9.5 mm and the aperture is 20.8 mm (depth of 36.9 mm). As it is not easy to make inner 29 angle this horn consists of 2 parts.
Wave length = 12.5 mm
WR-42: 10.7 x 4.3 mm

24 ghz horn

Left: feed f/D = 0.66
Right: feed f/D = 0.71

24 ghz horn

24 ghz horn

3. Transverter

Tx power: 2.9 W
NF: 3.7 dB


24 GHz Transverter

4. PLL with 11952 MHz output

I use a modified NORT PLL to obtain 11952 MHz for the transverter input. I removed the internal 20 MHz quartz and mounted a SMA connector which is an external reference input now.
See more under electronics.
Output power : 13 dBm


ADF4153 parameters for reference frequency of 20 MHz. VCO output is 2988 MHz and this gives 2988 *4 = 11952 MHz for our mixer.


I prefer 23.715 MHz as reference frequency. The reason is that I use output B (locked to output A) of my GPSDO for my 76 GHz transverter and output A for my 24 GHz transverter.


5. GPS disciplined reference oscillator to set PLL reference input

Here I use a nice unit by Leo Bodnar. It has 2 separate outputs (3.3V CMOS level) from 450 Hz to 800 MHz and it uses GPS reveiver for very stable output frequency.
Output power up to 13.7 dBm
Current consumption @ 12V DC: 190 mA

GPS reference

6. IF receiver/transmitter

Therefore I use my modified IC-705 to switch the transverter into TxOut mode.


7. Accu Pack

I use a 12V LiFePO4 accu with 10Ah because of its light weight, only 1.4 kg.