April was quite productive for the technical committee. We began with installing the new tone board at Marshall Manor on our April 1 visit. This also involved updating the firmware in the controller to support some new macros that allow us to remotely enable and disable the outgoing CTCSS tone. We can now enable full CTCSS tone squelch on our radios to eliminate hearing other machines on 146.760 and other undesired noises.
We also worked on some “putt-putt” type noises occasionally heard. We isolated this to a behavior of the combination of the existing power supply and the battery charger/switcher during some phases of battery charging. This existing power supply was supplying higher voltage than desired, and was not capable of being adjusted to 13.8 volts. Installing a temporary supply resolved the noise. We planned to replace the supply with a new Astron ASAP.
On April 8, Jeff Heavlin, K4OLW and I installed the new Astron 35 amp supply. This resolved the noise it was expected to address. No problems were observed and the visit was a success.
Since then, we’ve become aware of a hum on the repeated audio. We’ve been studying the symptoms, and are planning a visit soon to do site work to hopefully resolve this annoyance.