2008 Updates

    Welcome to KC5EFM on the 3 cm band. His homemade transverter worked well at 16 miles, so far.

KC5EFM's 3cm transverter. A DEMI transverter control circuit is used to interface the IF radio.

The 10224 MHz LO is split to feed the Transmit and Receive mixers.


KE5HHU Lowest band first...


This is the assembled unit for use on 222 MHz using a 24 MHz IF.

Power and Status Indicators. Green for power, Yellow indicates in-band for the IF, and Red for transmit.

Control and IF connections. This connects to the Yaesu FT-817 ACC port.

A look inside.

5 Watt amplifier.

The antenna BNC is on the right, with T/R relay close by.

My 222 MHz antenna is this 3 element yagi.

The 33cm and 23cm units are DB6NT kits that Mark, N0IO assembled. I interfaced the power and antenna switching.

DB6NT 23cm unit.

View of transverter and switching relay.

Weather resistant package.

DB6NT 33cm unit with external power amp. Switching relay and connection plumbing shown.

Mounts directly on the antenna U bolt. About 20W output.

These are the 23cm and 33cm loop yagis.

33cm transverter in its plastic tub.

23cm transverter with amplifier.

Power control and IF switch relay.

24V 20A power supply.

Everything that goes into the big tub.

As it sits in the big tub.

The RF and power lines enter just below the handles so the holes are shielded from rain.

Here is a view of the tub at the base of the mast with Heliax feeds to the 23cm and 33 cm antennas.

3cm DEMI Transverter

This is the repackaged 3cm transverter and other assorted parts.

Left to right, transverter, power amp, power regulation, case and heatsink.

End view of the DEMI transverter. I built this from a kit.

The 3cm PA is built on a slide tray along with it's switching circuitry.

10V regulation module for the PA.

Assembled in the box.

Connect and slide the PA tray into the box.

The beacon keyer module is mounted on the opposite end of the box.

Assembled unit.

Stack with the transverter box.



The first three transverters I acquired were the 13cm, 9cm, and 5 cm DEMI versions from N0IO.

These three are packaged together and mounted to the back of a 29 dBi grill type dish.

We built a IF selection relay module and an array of relays to switch the T/R for each band

and connectivity to the log periodic (WA5VJB) dish feed.

Three transverters mounted together. 13cm, 9cm, 5cm.

Assembly mounted on a dish.

The next two transverters also came from N0IO. These are for the 3cm and 1.2cm bands.

They are mounted together on a tripod base each with their own horn antenna. The DEMI 3cm

transverter is below the Yaesu FT-817, the IF radio for both bands.

Rear view of the 3cm unit, the IF radio, the LO and its power supply for the 1.2cm unit.

Side view of the 1.2cm unit. From left to right, the LO power supply, the 12GHz LO, the 24GHz assembly.

The 24 GHz unit contains no moving parts. All input/output switching is done with circulators.

The DEMI 10GHz unit, and 20 dBi horn.

Looking down the waveguide. Don't do this!

This pi shaped object is the transverter, filter, circulator, receiver, circulator, transmitter, and horn.