24 GHz

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The UK Primary 24 GHz or 1.2cms allocation is 24.000 - 24.050 GHz with the centre of the narrow band operating segment at 24.0482 GHz. Wideband operation is centered around 24.025 GHz. In addition there is further secondary spectrum between 24.050 and 24.250 GHz of which the first 100 MHz is not currently permitted to be used. Consequently the Primary allocation is recommended for all current and future usage.

Band Plan

See the RSGB 24GHz band plan for full details.

Beacons

There are a number of narrow band beacons in the 24GHz band - see this page for an up to date list.

24 GHz Equipment

The easiest way to get on 24GHz is to modify 23 or 26GHz telecom link equipment.

A very good example of this is by G1EHF which shows how simple it is to get on 24 GHz.

DA 24GHz.JPG DA 24GHz side view.JPG


Internally, the transverter largely comprises DMC modules from a ex-23GHz microwave link. The synthesiser and filter have been retuned to the 24GHz band, with the preamplifier, intermediate amplifier and power amplifier connected in series. These are then reversed using a coaxial transfer switch between RX and TX, providing a reasonable noise figure on RX and around 100mW on TX. An MM94P mixer and retuned filter are common to both RX and TX paths.

The transverter runs from a single 12V battery and uses an FT817 on 430MHz as the IF

DA 24GHz internal view.JPG


The antenna is by RFS with a gain of around 36dBi.

DA 24GHz front view.JPG

Putting a system together

Perhaps the first thing to get is your dish as this determines the hardware form factor of your system.

Then collect and test the modules, typically these will be:

  • Local Oscillator block plus multiplier
  • Receive module
  • Transmit module
  • Antennae change over system - wave guide or high quality SMA relay.

Local Oscillator requirements

To operate on the NB segment at 24,048.2 MHz the following LOs are required:

  • 144 MHz IF = 24048 - 144 = 23,904 MHz (/2 = 11,952 MHz)
  • 144 MHz IF = 24048 + 144 = 24,192 MHz (/2 = 12,096 MHz)
  • 432 MHz IF = 24048 - 432 = 23,616 MHz (/2 = 11,808 MHz)
  • 432 MHz IF = 24048 + 432 = 24,480 MHz (/2 = 12,240 MHz)

DMC Equipment

DMC modules are used by a lot of operators and there is a lot of information available on the web:

  • Notes on Switch setting for DMC 20 GHz source by Rex Allers, KK6MK File:DMC_SW.pdf

Elcom synthesisers

A very common unit to generate the 13GHx LO (doubled to 24GHz) is to use the Elcom 1201 synthesiser available from ebay.

Thales Alcatel 23GHz equipment

A lot of Thales / Alcatel equipment appeared on the second hand market around 2010.


Other station's systems

24 Ghz Power amplifiers

24 GHz Antennas