Transmit chain

Click the schematic to the left for details on how things are planned at VK2CMP for EME operations.

There are three feedlines between the shack and the antennas. One for transmit and two for receive (one each for the H-pol and V-pol RX systems.

The main feedline is LDF4-50 heliax that terminates up the mast on a relay that allows for Horizontal or Vertical polarization for transmit.

Currently the transmit path starts with a Elecraft K4D which uses its internal USB audio modem connected to the shack PC. 

The K4D transmits at 28Mhz via the transverter port to a Kuhne transverter.

The transverter up-converts the 28Mhz output from the K4D to 432Mhz. Its power output is up to 25 watts which drives the Power Amplfier.

The transverter is locked to a 10Mhz Rubium reference. These are easy to acquire from eBay and more convenient than a GPS locked reference. I do not lock the K4D to the Rubium reference as when I tested the K4D it was within 2Hz so I kept it simple and just locked the transverter.

The station runs a Beko HLV-1470 power amplifier. It currently can easily output 1000 watts to  the separate TX feedline to the transmit relay up the mast. The Beko is a dream amplifier as it runs very quite with its internal blower keeping it cool.  I normally just run around 750w at the PA hardly works up a sweat. 

I have a Special Condition to my licence which permits me to run 1KW for the purpose of reflecting signals from a celestial body!

First up on Transmit is a manually operated H/V pol relay that lets the operator select the desired transmit polarisation.

Each polarity (system) has its own antenna relay which selects the transmit path or the two recieve paths. Its operated by a sequencer in the Kuhne transverter.