Trans4m Transverter Kit by Chris Bryant G3WIE

The Trans4m is a 70MHz 4m transverter with either 21MHz or 28MHz input and available with standard or high dynamic range receiver options.

Designed by Chris Bryant G3WIE.  Specifications as below:

General

Size: PCB 180 x 125mm
Total height required 52mm
Input Frequency: 21MHz or 28MHz, combined or split transceiver connection
Local oscillator: Butler crystal oscillator as standard. Packaged oscillator (XCO, TCXO etc) can be fitted, but not supplied
Power supply: 12.0v to 14.5v
Power consumption: Rx 300mA, Tx 350mA (maximum with all options)

Receive
Gain from 70MHz I/p to transceiver o/p: 10dB – 15dB
Preamplifier: Dual gate mosfet (typ BF998), or MMIC (typ SPF5043)
Mixer: Balanced diode mixer (level-7 or level-17)
Noise figure: 2dB or better. Antenna noise on 70MHz will swamp
transverter noise.
Filtered and amplified 70MHz o/p for "USB dongle" or other SDR

Transmit
Drive power at 21/28MHz: 10μwatts (-20dBm) to 5w (37dBm) by fixed
attenuator change
Output: 0 - 100mW (20dBm) varied by voltage-controlled PIN diode attenuator
Spurious products: Better than 50dB wrt PEP
Intermodulation distortion: Better than ~45dB wrt PEP

At the current time we are supplying a kit of parts, excluding the PCB and 3 semiconductors which can be purchased from G3WIE directly. 

Those wishing to build the Trans4m are advised to join the yahoo group for latest information, build instructions and de-bugging advice.

https://groups.yahoo.com/neo/groups/Trans4m-transverter/info