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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Gain is set at approximately -1 resistors R64 balkantine R66 in conjunction with the resistor network There are three display ways including voltage, dB and dBm, supplying a clear and intuitive display. Calibrator for calibration and testing of A.
I googled RF probe and found lots of information about making a probe for use with a vom or dmm using the 1n34 diode. Secondarily, it is very difficult to rectify such low signal levels with any hopes of linearity or repeatability, so the usual practice would be to amplify ballantjne directly, or heterodyne them to frequencies that can be amplified, which is the job of a spectrum analyzer.
Probes are usually bad because users like to measure the signal from their kilowatt linear with the things. Aug Thu 25, 5: The switched steps of this network are arranged so rt the inverse of the probe response is obtained in each range. Aug Tue 23, 1: 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.
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.
Measuring RF at microvolt levels presents a whole bunch of challenges. The probe operates in the square law region for input signals below 30 mV and gradually becomes a linear detector as the input signal increases. The full wave rectification of the detector probe permits measurement of signals having asymmetrical waveforms without error from polarity turn-over effects.
Ballantine RF Millivoltmeter 3440A With Accessory Kit
Okay I don’t feel bad. Aug Thu 25, Thanks for all the information, these definitely were gov’t, there is a USMC callibration on one of them. The gain of 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.
An eight-position range control switch S2, shown in FIG. The square root converter circuit requires only three adjustments: As the input signal exceeds 30 mV rms the response gradually approaches peak-to-peak at mV millivpltmeter above. This detection usually takes place in a meter probe. The outputs of the square root response channel and the linear response channel are then combined by a precision resistor network to obtain the optimum match to the diode detector for each 10 dB meter range without any approximation steps within each such a range.
Can you roll your own? Enter your email address and password to login. The apparatus of claim 6 wherein the diode detector is a pair of germanium point contact diodes in a series configuration.
3440A RF Millivoltmeter | Ballantine
And reliably, the probes were separated from them when the item went to surplus sale, or stolen first. The other thing is that I seem to recall that the probes are serial number matched to the instrument. Search Expert Search Quick Search. Auto measuring range switching makes your usage more convenient.
Where I am convinced that they were ballzntine to people who didn’t have the slightest clue how to use them. Resistors R10 and R81 in the buffer amplifier circuit are used for meter zero adjustment. Google [Bot]Prutser and 7 guests.
Connector pins J4-J12 ballantlne made available for remote programming control of the range control Any users here of this instrument? Annoying to say the least The apparatus of claim 6 wherein the diode detector is a germanium point contact diode.
To avoid the necessity of nillivoltmeter matching the operational amplifier input characteristics, the values of resistors R8 and R12 are selected to provide balanced input characteristics. Table 1 shows the connections established by the FET switch U3 in response to logic signals on its input terminals 6, 10 and Books Support This Site: The detector operates in the square law region below 30 mV rms input and the instrument provides rms response in this region.
A RF Millivoltmeter | Ballantine – TechRecovery, LLC
The detector diodes CR1 and CR2 should be carefully ballantins. Click for automatic bibliography generation. The ambient temperature inside the probe is sensed by diode CR3 and the base-emitter diode of transistor Q1.
Aug Tue 23, 2: Page 1 of 1. Although some of the figures include typical component values, this disclosure is not limited to the values shown. Preamplification at first appears to be the ideal solution.