de F5AHO, une MN2000 magifique

De Uli, DK4SX, refonte complète d'un TR7, cela relève de l'art, chapeau bas Monsieur Uli

Here are the first fotos of my "reborn" TR-7: Front, bottom and top. Here you may see all of the hardware details. On the front you will notice the large frequency display down to the 1 Hz digit, showing also the RIT/XIT offset, a bargraph display of the BTP tuning and the digital display of the rx bandwidth. The meter displays all importand parameters of rx and tx. I added a tx power control and a broadband front speaker. 

On the top view the shielded RF modules can be seen. All the RF wiring is on the top for better testing. The compartments contain more or less the original TR-7-PCBs plus several options (DDS, speech processor, third IF with notch filter, low noise preamp etc.). The filter boards are on the right. You see the original high pass filter board as a hybrid on the larger board. This contains the relay switching, the ALC circuitry and the automatic SWR metering. I added a small additional board with a pin-diode attenuator to equalize the heavy gain deviation of the transmit path. The transmit low pass filters are situated on a board underneath the high pass filters in a separate shielded chamber. 

The bottom shows the integrated power supply with a large toroidal transformer. This is arranged below the filter compartments. The rf modules are plugged into connectors on a separate chassis, where discrete wiring allows later modifications. The low noise fans are thermostat activated and keep PA and power supply pass transistors cool. Between front and RF/power supply the frequency and functional processor boards are installed. They are connected to keyboard, display and rest of wiring by ribbon cables. The back panel carries power supply regulators and pass transistors with heat sink and the original pa module. I hope this description will explain the main aspects of this project.

de F5NWG, un spendide L4B