[ARC5] Resistor Excursions

[releazer at earthlink.net]

While a more accurate measurement of resistor value can be made by first removing the component from the circuit, I think we can be assured that there are no circumstances in which the resistor being left installed can produce an INCREASE in measured resistance across its terminals.  And based on my experience with both older NOS carbon resistors and those installed in working radios, that is what I was looking for.  In addition the fact that the receiver has electron tubes mounted in sockets means that parts of the circuit can be disconnected rather easily.

I bought a Heathkit HW-100 on ebay some years ago and before I fired it up decided to run through the final post-assembly checks provided in the manual, including the point to point resistance tests.  I soon found some serious anomalies that would have indicated major problems with some of the circuits  and eventually, by circuit analysis, identified a number of gross errors, not in the radio but in the manual.  I can only assume that those resistance values were not attained experimentally.

Wayne
WB5WSV