High power amplifier for 1296
1 KW SSPA for 1.8-54 MHz
A 1.5 KW LPF for 160-6m
1.8 to 54 MHz Dual Directional Detector
1.8 to 54 MHz combiner set
Automatic Transverter Interface
1 KW 6 Meter LDMOS Amplifier
2 Meter 80W All Mode Amplifier
1 KW 2M LDMOS Amplifier
1 KW 222 MHz LDMOS Amplifier
500w 70cm Amplifier
1KW 70cm LDMOS Amplifier
A Big Power Supply for SSPAs
Low Pass Filter/Dual Directional Detector
Sampling RF Power
LED Bar Graph Meter
Amplifier Control Board
LNAs (preamps) and MMICs
LNA Sequencing and Protection
Building UHF Antennas
MIcrowave Marker
Crystal Oven Controller
Microwave L.O.
Latching Relay Driver
12 to 28v
Relay Sequencer
High Current DC Switch
L & S Band LNA
Microwave L.O. Filters
PC Board Filters
Using Inexpensive Relays
600w 23cm LDMOS Amplifier
XRF-286 Amplifiers for 23cm
150W 23CM Turn-Key Amplifier
300w 23cm Amplifier
200w 23cm Amplifier
100w 23cm "brick"
100w 23cm Transverter
60w 23 cm Amplifier
23 CM Beacon
23cm Signal Generator
23cm Double Quad
23cm filters
13cm filter
13cm Signal Generator
13cm Transverter
120w 13 cm Amplifier
300w 33cm Amplifier
33cm filter
33 cm Crystal Source
33cm Signal Generator
9cm Transverter
Transverter Selector
12 AND 28 volts
Klitzing Amplifiers
IC-910H tweaks
Audio Files
Parts I Can Supply
Current Projects

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9cm Transverter

Shown here to the right of the 1296 and 2304 gear is a 50-watt transverter I cobbled together for 3456 MHz.

Designed for portable operation, it runs on 12v, and has an OCXO-based local oscillator.

For the innards, I used a Down East Microwave low-power transverter kit, which I modified to mate up with a 50w Toshiba amplifier module and my own t/r control board, L.O. and I.F. interface.

The transverter can be driven with as little as 10 mw, but it does provide ALC feedback to the driving radio, and has a 14db input attenuator so that it can be used with just about any transceiver.

The ALC is used as a safety measure to prevent overdriving and damage to the interface.
The rear panel has the usual connections, plus a few extras I found useful, such as an L.O. sampling port, an "L.O. only" power connection, and a crystal oven temperature trimmer (useful for discovering the most stable crystal temperature).
On the inside, I tried to remember everything I should have done when building other things; so what I did was modularize with connectors on the major assemblies like the power amp, transverter board, local oscillator, t/r relay, etc.

The LO compartment is at the lower right. It's contained in the mini-box shown, wrapped with insulation on the inside. Within that insulation is the oven controller, L.O. and band-pass filter assemblies.

The three boards mounted above the L.O. are the t/r interface, sequencer and 28v boost converter (for the 28v antenna relay).

The 50w amp is located on the other side of the center separator wall, in it's own airtight compartment.

Worthy of mentioning is the accessibility of the adjustment trimmers. All of them can be adjusted by simply removing the top cover of the transverter, including the L.O. frequency netting trimmer visible in the previous photo.

Here's a peek inside the transverter module, showing the basic transverter board and it's connections.

When I assembled this, I used different values for the MMIC bias resistors to match up with my control board (8v for the L.O. and 12.5v for the others). I also did not install the last MMIC in the transmit chain; it was not necessary, as the Toshiba PA only needed 1mw drive for full output.

Inside the amplifier compartment, the 50w Toshiba amp mounts to a beefy heat sink, and is secured to the chassis with the brackets shown. This is a class A amplifier, drawing 20A continuous during xmit, and must be able to dissipate up to 270w.

The fan is mounted so that it draws air from the outside and forces it forward through the heat sink to the front panel, where it then flows up, back and out through the top vent holes in the rear panel.

This fan comes on during transmit, but will also run if the heat sink warms above 35C. There is a thermistor connected to that blue wire at the top right, providing feedback to the fan controller, which is located on the t/r control board in the other compartment.

Block diagrams and other schematics follow below.

Next, the TCLO:

This last drawing is the t/r control board: