[Test-Equipment] Q meter?

[Richard Knoppow]

----- Original Message ----- 
From: "Dale H. Cook" <radiotest at plymouthcolony.net>
To: <test-equipment at mailman.qth.net>
Sent: Wednesday, June 18, 2014 2:55 PM
Subject: Re: [Test-Equipment] Q meter?


> At 05:39 PM 6/18/2014, Brian Burns wrote:
>
>>It's made me curious about the usefulness of that device, 
>>or some other brand, on an RF experimenters test bench.
>
> I own two of them (a 160-A and a 170-A) but seldom use 
> them because most of the times when I need to measure Q 
> the frequencies are low enough for one of my other 
> bridges. It is quicker to use a rack-mounted bridge 
> already in the shop than to drag out a Q meter. When I am 
> developing or modifying an RF network it is generally a 
> filter network where the predominant concerns are corner 
> frequencies, passband ripple, and overall passband 
> response, and those measurements need my sweep generator 
> and 'scope.
>
> Dale H. Cook, GR / HP Collector, Roanoke/Lynchburg, VA
> http://plymouthcolony.net/starcity/radios/index.html

     I don't recommend the 160-A, its the one that has a 
delicate thermocouple. Easy to burn out and not easy to find 
these days.  I think you mean the 190-A UHF Q-meter. These 
actually work pretty well but like other instruments running 
in this range its necessary to watch out for strays and know 
what you are measuring.  The thermocouple is pretty rugged. 
While Boonton made some Q standard coils for it they are not 
as reliable as the ones for the 260-A. I hesitate to call 
the 190-A obsolete because it will still do what it was 
designed for but those working in the RF range it covers 
will probably prefer to use a network analyser.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com