The 3rd set of resistance tests for the Sender were completed yesterday and overall, the results were very consistent with the two sets of tests run last Spring.
Of none electrical note, the rust on my VTVM Testing Procedures is now shedding in huge chunks. Most of the red flag readings I took earlier that were ‘Infinity’ in nature produced excessively high, but real values this time around. This was primarily due to me focusing on taking advantage of the different testing ranges on the meter to see if and where I might actually get a useful reading. It is amazing what one can forget when being an infrequent user of helpful equipment.
The majority of the good readings were either identical to the earlier ones, or +/- very, very close, so that was nice to see as well. The red flags are all clustered in the same circuits as earlier and the other big plus was nothing new showed up that might have been related to the overheating event that happened a few weeks back, so I have inflicted no new damage…so far.
The dark side of all this, however, is my next step in the process. I now have to go back to the Sender Circuit Diagram and methodically trace out each red flag circuit to identify all the related components. There are likely a few resistors that have dropped off in value, but most of the problems are probably going to be with the PIO Capacitors that have transformed themselves into resistors. The problem now though is the 52-Set Circuit Diagram for the Sender is very compact for easy reading/tracing. One sooner or later has to resort to using a magnifying glass, or lamp, which narrows down your field of view, compounding the problem. A whole different experience from working with 19-Set diagrams.
The challenges don’t stop there either. Once I have identified all the components that need further investigation, I have to find them on the chassis and test each. The ones tied to valve socket terminals are the easy ones. It is the remote ones tied to a terminal panel, tucked behind another component, six inches away that create the nightmares.
Good thing it is a long Winter in these parts.
David
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