It’s the “no probes” part that’s the killer here. The probes are what gives the meter its bandwidth. Probes are usually bad because users like to measure the signal. Schematic of Boonton Model 92 A RF Millivoltmeter; Boonton Electronics Corp. . In the Ballantine Model A RF millivoltmeter, which is. The old Boonton RF Millivoltmeter or Boonton RF Microwattmeter or . Ballantine Labs A Standard RF Probe – 10KHz to GHz with pf.

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There was a QEX magazine article a while back about building a compensated RF 3404a using a pair of matched diodes and some high-impedance opamps, if you want to homebrew something.

Auto measuring range switching makes your usage more convenient. Aug Thu 25, 5: Numerous calibration adjustments are required with such successive approximation type millivoltmeters in order to optimize the match to the detector response.

Capacitor C17 provides damping on all ranges. Table 1 above includes a truth table for FET switch U8. Preamplification at first appears to be the ideal solution. It’s a foam lined plastic box with the probe and various adapter tips. Adjustable resistance Rg is used to adjust the gain of amplifier A 3 so that its output voltage V 3 is determined by the formula EQU3.

Aug Tue 23, 1: The switched steps of this network are arranged so that the inverse of the probe jillivoltmeter is obtained in each range. The apparatus of claim 6 wherein the diode detector is a germanium point contact diode.

Ballantine RF Millivoltmeter 3440A With Accessory Kit

My Boonton’s use millivoltmetrr diodes in the probe for full-wave rectification, which is then converted back to AC in the instrument via a mechanical chopper. These characteristics cause the probe to have high input impedance over the very wide frequency range from 10 kHz to beyond 1.

Adjustment of resistor R10 is only required at long intervals and when amplifier and probe components millivoltmeer replaced. Connector pins J4-J12 are made available for remote programming control of the range control Milliammeters, Ammeters, Voltmeters, and D.

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Click on a button to share this product: The gain millivoltmeter amplifier U4 is set by the ratio of the fixed resistor R37 connected between terminals 10 and 13 and the resistance coupled between terminals 14 and 2 which is varied by the operation of a three-pole double throw switch U5 typically a RCA type No.

The precision resistor network comprising resistors R52, RR63, plus the feedback network of meter amplifier U9, performs the required scale linearization. As a result of this filter, the response is down 3 dB at 2 Hz and falls at a rate of 10 dB per octave.

Where k is the mixing factor determined by a given position of the range select switch SW, EQU4 As a result, the output voltage V o of the meter drive amplifier can be defined as follows: Where I am convinced that they were supplied to people who didn’t have the slightest clue how to use them. Potentiometer R68 can be used to adjust the recorder output for one volt full scale open circuit or to normalize the output to the recorder being driven.

3440A RF Millivoltmeter | Ballantine

The voltmeter of claim 2, further comprising a range control circuit connected to adjust the input amplifier gain and to adjust the resistances of the resistance network in synchronism. The identification of specific components, component values and circuit details rv this specification are for illustrative purposes only. I have seen pallets of these meters at surplus sales, all wrapped in plastic, without a single probe in the bunch. Okay I don’t feel bad.

When remote programming is employed, the manual range control switch S2 is disabled by a signal applied to pin J6. In the 10 mV range, a further reduction is provided by substituting resistors R85 and R87 for resistors R84 and R86 in the voltage divider.

The resistor network R e determines the proportions of Vs and V a as components of V 4. The signal at the output of amplifier A 3 is applied to a square root converter SR and to a linear operational amplifier A 4. And its detachable design reduces your work in servicing.

Ballantine RF Millivoltmeter A With Accessory Kit | eBay

In the Ballantine Model A RF millivoltmeter, which is constructed generally in accordance with the embodiment described here, the following semiconductor device types have been used:. RVT type AC millivoltmeter have two channel input terminals,the available channels range from 10Hz to 1MHz,the measuring voltage from V to V,the two channel input signal can be measured simultaneously or separately by switch different setting of button,the meter input the signal through the BNC terminal,which can eliminate the influence of the external sensor signal in the condition of low electrical level measurement,it can be easily connected with the oscilloscope for the waveform inspection,or make the meter as a preamplifier.


Any users here of this instrument? The apparatus of claim 3 wherein the range control comprises a multiposition range switch, a plurality of data line amplifiers, each having an input connected to a portion of the range switch and each driving a data line, a first electrically controllable switch responsive to signals on a plurality of data lines for adjusting the gain of the input amplifier, and a second electrically controllable switch responsive to signals or a plurality of data lines for adjusting the resistances of the resistance network.

Successive approximation techniques are employed in millivo,tmeter radio frequency millivoltmeters such as the Boonton Electronics Corp. This switching arrangement balances the various internal leakage currents in the FET switches of U3 at pin 2 of each of amplifiers U1 and U2, providing a common mode signal.

Antique Radio Forums • View topic – Ballantine A RF millivoltmeter

Click for automatic milliboltmeter generation. The connections made by switch U14 are given in Table 1 above. Google [Bot]Prutser and 7 guests. Measuring RF at microvolt levels presents a whole bunch of challenges.

A number ballantije techniques can be used to minimize temperature effects. Some of the old Millivac RF voltmeters MV series, for examplecould get down to the single millivolt range with nothing more than crystal detector probes. The apparatus of claim 5 wherein the diode detector is a germanium point contact diode.

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