Thought about Getting active on the 23cm (1296 MHz) Band?
The following article describes a 23cm FM Transceiver kit, with excellent features, able to be built by anyone with experience in VHF/UHF construction techniques and SMD skills.
Here in Sydney, FM is the most common 23cm operating mode, with a couple of operational FM repeaters, weekly WIA / ARNSW broadcasts and a small but active community on-air daily.
Maybe you have investigated acquiring a 23cm transceiver and found it is not that simple.
Unfortunately, new equipment is not readily available in Australia, and what is on the market is high end equipment at a matching high end price. Importing equipment into Australia comes with inherent risks.
Not surprisingly, the second hand market in Australia is thin or non-existent. Again importing 2nd hand into Australia also comes with inherent risks. Is the equipment in working order and compatible with the Australian band plan.
Another option, a transverter will convert TX/RX from a 2m (or 70cm) transceiver up to 23cm. Transverters are typically “all-mode” – if your 2m (or 70cm) rig is capable of FM & SSB then you will be operating FM & SSB on 23cm band. Again, will this combination be compatible with the Australian band plan.
Why not build your own transceiver? This sounds daunting - but is surprisingly simple, satisfying and way cheaper than buying off-the-shelf.
Two SGARS members have teamed up to make building your own 23cm Narrow Band FM Transceiver, a possibility.
Richard VK2VD has reworked the design of a 23cm transceiver, originally developed by Bas de Jong PE1JPD in Netherlands. Richard has sourced replacements for obsolete components, which have been identified & tested, suppliers confirmed, and an updated PCB designed.
Richard’s final production model of the 23cm Narrow Band FM Transceiver, includes the following features and specifications;
· Narrow Band FM (transit and receive)
· Full 23cm band coverage
· Simplex operation
· Repeater operation with user-defined TX shift (including 20MHz)
· Output up to 0.7 watt (15w optional)
· NF approx. 3dB
· 4-line back-lit LCD displaying Frequency, Repeater Shift, RX/TX status, S-Meter
· Digital VFO operation in 1, 5, 25, 100, 500KHz or 1MHz steps (user selectable)
· 10 programmable memories, each with unique repeater shift and CTCSS
· Memory scan function, with pause-on-squelch
· Open-source software (MIT licence) – source code available on Github
The kit includes a comprehensive construction guide (including schematic), printed circuit board and components.
Image shows a completed kit.
What is not included is microphone, speaker, any components not PCB mounted, connectors, mounting hardware, case, etc. Also, you will need to add your own antenna system.
To improve the performance of this transceiver, consider the addition of;
· 15W RF output – Increasing the transceiver RF output to 15W can be achieved by adding an antenna relay (minikits.com.au) and 15W 1200MHz power amplifier module (available from AliExpress). The power module identified has ~40dB gain and so requires a ~23dB attenuator at it’s input to avoid over drive. It operates at 24-28vdc which can be supplied by a cheap 12v/24v switch mode inverter (eBay or Aliexpress). No tuning or alignment of the 15W PA is required. This option is described in the construction guide.
· RF Pre Amp – Operators in quiet areas working weak stations may benefit from the addition of a pre-amp to increase front end sensitivity. A simple preamp based on PGA103 has developed. This option is described in the construction guide.
Peter VK2KFP has teamed up with Richard to make this kit available at a really attractive price, for the first batch of kits.
- SGARS members-only introductory offer $60 (no shipping, cash-only, pick up in person at SGARS get together, or collect from Peter VK2KFP QTH)
- Normal price, for non SGARS members, $70/kit (plus $10 pack and postage by Australia Post. Insurance not included.) Payment by Paypal or EFT accepted.
The fine print
This 23cm transceiver kit requires the constructor to have some prior experience with building similar projects, or you are up for a challenge. Construction involves soldering of Surface Mounted Devices. Whilst alignment is minimal, you will need a 23cm signal source, such as a NANO VNA and some type of power meter. Only minimal assistance can be provided as Richard and Peter assume you have purchased the kit on the basis that you have the skill, knowledge and equipment required. No refunds. The St George Amateur Radio Society Inc has not been not involved in the preparation or distribution of this kit and therefore accepts no responsibility.
Orders & Queries & Feedback related to this kit should be sent by email to