02-02-2022, 01:18 PM
Because I'm a bit of a head case, I've been restoring a huge CT218 RF signal generator (AKA boatanchor). That had very many leaky paper capacitors, replaced with axial polyester. The CLCLC main filter had two capacitors totally kaput; fortunately none of them duals. I managed to find 32uF500V caps that fit the chassis clamps. Other 4uF cracking seal electrolytics were replaced with (oddly cheap) audio axial polypropylene, which also fit the original clamps.
There were other issues, now all solved. Including a cathode resistor in the modulation oscillator that had never been soldered, was near to but not soldered to the ground tag, and was not even tinned! So modulation could never have worked, or checked in manufacture.
Performance is (now) bang on - which is going well for a 56kg animal that was built by Marconi in 1956. It is a two person lift.
7 turret tuned ranges from 85kHz to 30MHzwith fine tuning on a 2.5 meter film scale, AM, CW, FM. Calibrated output down to 0.1uV.
Craig
There were other issues, now all solved. Including a cathode resistor in the modulation oscillator that had never been soldered, was near to but not soldered to the ground tag, and was not even tinned! So modulation could never have worked, or checked in manufacture.
Performance is (now) bang on - which is going well for a 56kg animal that was built by Marconi in 1956. It is a two person lift.
7 turret tuned ranges from 85kHz to 30MHzwith fine tuning on a 2.5 meter film scale, AM, CW, FM. Calibrated output down to 0.1uV.
Craig
