[Test-Equipment] TM4520 inductors

[Miles B. Anderson, K2CBY]

This is a standard coil set used in conjunction
with a "Q" Meter. They can be used to calibrate 
the Q Meter, to measure capacitance connected in 
parallel with the standard or to measure inductance 
connected either in series or in parallel with the 
standard.

Boonton Radio developed the original Q Meter in the 
late 1930s and sold it as Model 160, later superseded by 
the Models 260 and 260A.

Marconi had its own version known as the TF-1246, 
which used a separate RF oscillator. They also sold 
either the original Boontons or license-built clones 
of them. (There is one for sale now on ebay 360127515604.)

Hewlett Packard also manufactured Q Meters in the 1950s 
and 1960s and some were sold to the US military. HP 
discontinued US production some years ago but HP clones 
were made by an affiliate company in Japan.  

"Hobbiest" grade Q meters were sold by Advance 
Electronics in England and Heathkit in the USA.



Miles B. Anderson, K2CBY
16 Round Pond Ln.
Sag Harbor, NY 11963
Tel.: (631) 725-4400
Fax.: (631) 725-2223
e-mail k2cby at optonline.net