[Test-Equipment] TV-7 Calibration

[DW Holtman]

Ed,

Thank you for the great link. I know that Nolan is an SK, glad that someone 
is keeping all of the great information he so hare on worked on available 
for all of us. The data sheets he made for the TV-7 must have taken tons of 
hours.

Best,
DW Holtman
WB7SSN

----- Original Message ----- 
From: <k4pf at juno.com>
To: <test-equipment at mailman.qth.net>
Sent: Thursday, October 11, 2007 3:46 PM
Subject: Re: [Test-Equipment] TV-7 Calibration


Hi,

I recommend that you check out Nolan Lee's web page on the military
tube testers:  http://www.webdsi.com/nlee/
His data sheets are more up to date than the military's, as well.
An amazing amount of work!

He points out the necessity of using a d.c. voltmeter
of the correct 1000 Ohm/Volt loading (or adding the proper
resistance across the input of a modern Hi Z instrument),
to duplicate the test equipment used in the military
test procedure.  This is important because the bias pot/screen supply
circuit is at high impedance, and the manual took into account
that they were using a 1000 Ohm/volt meter to do the measuring.

The military meter has a 50V scale and a 10V scale, so you will
need a 50K resistor across your probes to check values between 10V
and 50V, and a 10K resistor across the probes when measuring
below 10V.

73,
Ed Knobloch


-- "DW Holtman" <tubestuff at comcast.net> wrote:
Hello,

I'm getting ready to go through a TV-7/U, step by step using the Depot 
manual (TM-11-6625-274-35). The first step, the bias voltage test calls out 
a test setup then asks for a reading of 3.0 +_.1 Volts. I'm reading 5.26 
Volts.

My question is this. The procedure calls for using a TS-352 Multimeter. The 
only meters I have are high input impedance DVM and a VTVM. I know that a 
TS-352 will load the circuit and cause a lower reading. Is there anyway to 
make the necessary adjustments using a DVM or a VTVM?  <snip>

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