Manual for Boonton Q Meter Type 260-A.

Compliments of Lance Benner.


Although Boonton company made a number of Q-meters, the 260A probably
represented the state of the art. With two meters, it is straightforward to
"dial in" the device under test and read out the Q with great accuracy. It is a
remarkable device. The first part of it is a power oscillator that goes from 50
kHz to 50 mHz in 8 ranges. Looking at it on the 'scope shows it to be a very
pure sinusoid at all ranges. If you have ever looked at the VFO output in a
general-coverage receiver, you will know that purity across all bands is
something of a miracle. The amplitude of the oscillator output is controlled by
a dual wire-wound theostat that controls the screen voltage (!) of the
oscillator. To get the true RMS current through the DUT (Device Under Test)
over all frequencies, the 260A uses a thermocouple (!) that drives a
microammeter. An amazing piece of engineering. I don't think there is anything
on the market today that does what this device can do.

And this is the Alignment and Test manual for models 160A and 260A Q-Meters.
This is the one you need if you have a 160A or 260A that is out of alignment
and you have some Q-standards and are ready to try to put it into perfect
alignment.  This is not for the casual user.