Ever since the advent of radio communications at the start of the 20th
century there has always been a need for test instruments. This month, we take a
look at some of the common test instruments that were used and describe the
unusual Weston Radio Set Analyser Model 660.
The Weston Model 660 opened up and ready for action. The abbreviated instructions are on a label attached inside the lid.
Many different test instrument have been used in the radio field
over the years. Some are quite complicated but sometimes they can be extremely
simple – even just a finger or a screwdriver!
For example, with octal and pre-octal valves, it was common for
the control grid to come out to a cap on the top of the valve. As a result, it
was common for a serviceman to touch the grid cap of valves like the 6B6G to see
if there was a healthy "blurt" from" the loudspeaker due to the resulting
injected hum.
This test method was quite effective in determining that the
audio amplifier was actually working. However, it gave no real indication as to
how well the stage was operating.
