The PA4EME shack may look less impressive than expected because it is not meant to be an exhibition of equipment only. Lifespan of equipment varies from 1979 until now and represents the change from analog to digital. Large tube amplifiers with lethal high voltage power supplies have been replaced with Solid State Power Amplifiers.
Most of the work is done by two Javornik 144/14 transverters. The oldest version of the transverter is the original design as published by S53WW and home-built. This transverter is followed by an IC-7300. The latest version of the Javornik 144/14 is built to be used for digital EME on 144 MHz. This transverter is redesigned as parts from the original design became absolete. This was done completely inhouse, from PCB-manufacturing to the build. 144 MHz signals from the XPOL yagi’s are fed into the synchronous working duo channel transverter and the output is analog send to a duo channel Afredi 822x SDR-receiver. The Afredi 822x converts analog to digital and send his output to Linrad 4.07. Here both H and V signals are used for adaptive receiving and Linrad sends his output to MAP65.
Various types of transceivers and amplifiers passed during more then 40 years of 144 MHz DX. The pictures below are showing a few of them. The R2-CW must be the rarest item. This Czech designed transceiver is not found often as only a limited number was made and even after 30 years it is considered one of the best designed analog transceivers with a low noise figure of it’s own and a very clean transmitting signal with extreme low phase noise. This makes it ideal to use with high power amplifiers.
The video below is showing the first setup for digital EME using MAP65. In practice the configuration turned out to work fine but was not good for the traditional modes as the receive and transmit lines are different and changing it all the time is not fool proof in the heat of the DX-battle. So a complete second station was build with a new PA4EME 144/14 Javornik transverter and an IC-7300 transceiver. The IC-7300 does not comes with seperated receive and transmit so that was added too and that also gave the possibility to add a hardware TX-inhibit to the IC-7300 and a solution for the spikes on the start of the transmissions that will kill modern SSPA’s. More details can be found in the technical corner of my webpage.
PA4EME 