[Test-Equipment] TM4520 inductors

[Dave Brown]

I'm fairly sure that the Marconi TF1245 was  actually the last in 
their line of analog Q meters. It's still considered one of the best 
and commands reasonable prices on the secondhand market. The TF1245 is 
the actual Q meter while the associated  oscillator was usually the 
TF1246.(40 kHz to 50 MHz). There was also a less common oscillator, 
the TF1247, that covered 20-300 MHz.The oscillators and the Q meter 
were often fastened together for convenience.

There were others. One of the more common earlier models is the TF329, 
I have a TF329G with a partial set of reference inductors. It's a big 
heavy brute of a thing to move round but does the job admirably.

I don't think that the Advance Q meters were considered 'hobbiest' 
grade, but they were certainly not in the same league as the Marconi 
instruments.  Advance generally looked to supply the radio/tv 
servicing market but they did make a range of semi-professional test 
gear as well.

Regards,
DaveB, NZ


----- Original Message ----- 
From: "Miles B. Anderson, K2CBY" <k2cby at optonline.net>
To: "Test Equipment Mailman" <test-equipment at mailman.qth.net>
Sent: Thursday, January 29, 2009 6:32 AM
Subject: [Test-Equipment] TM4520 inductors


> 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 late 1930s and sold it as Model 160, later superseded by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
>
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