Kerry NH2A recently decided to adopt and restore an orphan boatanchor Hallicrafters SX-99 all-band HF receiver. This kind of rig was a standard part of a receiver-transmitter pair that hams used to use back in the day. He replaced the fraying line cord and all the paper and electrolytic capacitors before ever even thinking of powering it up.
The radio is vacuum tube based and Kerry used a Heathkit tube tester to verify that the tubes were at least operational. He then brought the rig up slowly on a AC variac with the tubes removed to confirm the tube filament and plate voltages were present (and no smoke was produced!). Once he verified the power supply was working correctly it was time to return the tubes to their sockets, hook up the speaker, connect a short antenna and keep his fingers crossed. Kerry was rewarded by the sweet sound of our own local AM radio station WMBG on 740kHz.
Here’s Kerry inspecting the top side of his receiver.
And here’s the result…his big smile indicates the radio has at least come to life receiving AM signals; more work is required to get the receiver working again in the CW mode but that’s what ham radio is all about…doing it yourself!