SGC SG-2000 Relay Repair for Deaf Receiver

In this video, the LPF relays on an SGC SG-2000 are replaced. This cures the deaf receiver issue and improves output power. Along the way, we'll discuss some of the design weaknesses of passing the receiver through the transmitter LPF, as well as the thermal design of the PA and the rather brutal cutting of most bottom solder joints. At the end, we perform a sweep of the Low Pass Filters on the Marconi 2947, and then perform a sensitivity test for the SSB receiver. Schematics: https://web.archive.org/web/201801180... Table of Contents: 0:00 Intro 0:50 Disconnecting the wires and screws 4:15 Board Removal 5:50 Where is the heatsink? 7:00 Interesting observations 8:18 Heat transfer discussion 15:40 Start unsoldering the relays 16:39 Comparing the new and old relay 17:40 Footprint verification 18:44 All relays out and cleaned board 19:15 Soldering in a relay 19:49 All cleaned and all relays in 20:29 Installing the board back into the chassis 22:23 Power On 22:54 Test #1: Verify LPF using Analyzer with Tracking Generator 26:19 Receiver Design Weakeness 28:21 Test #2: Sensitivity Test 31:31 Sebnsitivity Test Results for all bands 31:49 Harmonic Test Results