233D Transmitter Restoration Project
Some progress today.
Loss of feed to the audio power supply was determined to be a loose connection on a terminal strip. Mike is going to closely inspect all of the terminal strips to determine if we have other potential problems. The Autotune dial mis-wire that he discovered last week appears to have made the dial pulse system work considerably better.
And now the Autotune motor appears to be working, so we can really get the channel select system going. There are still what appears to be some relay issues in the Telco assembly, but we should be able to work through them.
Rod brought in resistors to replace those in the Tone Control chassis. Most of the old parts had drifted well out of tolerance high, so replacing them should improve performance. We are still attempting to understand the undocumented mods in the carrier control/keying circuit.
We are now looking for ways to construct a 9 dB pad to reduce the 3 KW carrier to 375 watts so we can legally operate on the ham bands. We think operating the transmitter at full power will provide the best results. We hope to dissipate some of the power in the transmitter room before we transform to the 50 ohm feed-line and take care of the balance after we get to the roof.
Al Tupker stopped by so I will copy him on the reports.
| November 13, 2014