HP 432A Power Meter Sensor and 8102-1082 Sensor Cable

Description

Maples Road Instrument Services
9107 Maples Road
Fort Wayne, Indiana
46816
Specializing in Technology That Mere Mortals Can Still Understand
This auction is for an HP 432A Power Meter - (S/N 1848A299xx ), HP 478A Coaxial Thermistor Mount  (S/N 860xx) and an HP 8120-1082 5-foot
interconnecting cable.  (I have no
idea
why some text in this listing is bold and some isn't.  It is a text editor quirk that I can't
fix
)
The HP 432A is not an RF meter, it really a sensitive differential voltmeter that measures the voltage difference between two sets of precision thermistors in a bridge circuit; one set producing a voltage due to the RF power applied to the sensor, the other compensating for ambient temperature.
This HP 432A meter was calibrated in accordance with HP Tech Manual
00432A-90079, Section V (Change dated 22 October 1975).
The calibration was done with an HP 8477A calibrator (as called out in the referenced manual) whose calibration is traceable to NIST standards.
The HP 478A sensor is specified for operation from 10 MHz to 10 GHz and when used with the HP 432A provides full-scale power measurements from 10 micro-watts (-20 dBm) to 10 milliwatts (+10 dBm).  Measurements can be made with 0.2 dB resolution down to 3 micro-watts (-25 dBm).   This particular sensor has an outstanding Return Loss of greater than 32 dB at 1.3 GHz and has at calibration factor of 100% from 100 MHz up to 1.3 GHz where I run out of generator to check it.
The meter, cable and sensor have been checked out together as a complete system.
The Coarse Zero pot is clean and adjusts smoothly over its entire range - no skips or intermittent spots. The plastic side, top and bottom panels of the meter are almost pristine.
The front panel is clean, no scuffs or scratches.
Markings are clear and do not have wear from use. The 100-200 ohm selector switch knob is a replacement.
My test and cal capabilities include an HP 8477A Meter Calibrator for the HP 432A and an HP 3468B DC voltmeter calibrated and traceable to NIST, which I used to calibrate the HP 8477A. The HP 432A was calibrated in accordance with the HP procedure using an HP 8477A and it meets all of the original HP specs.
The sensor has a
solid metal ring type-N connector.
The RF connector is in good shape - no dings or nicks either on the shield or the center pin.
The sensor is the late style metal interface.
The 6-pin output connector is in perfect shape.
There is a calibration sticker on the sensor, and I have left the Cal Factor chart from that calibration on the sensor since it goes up to 10 GHz, which I cannot do.
In their October 1975 Manual Change Pages, HP deleted the calibration procedure for the meter and sensor as a pair, calibrating only the meter as a DC instrument.
Sensor cal was declared to be a "return to HP for calibration" type of procedure.
I do a comparison to an HP 435B and HP 8481A to make sure that the sensor is in good shape as far as linearity and frequency response are concerned.
I will provide calibration data for the meter and cross check data for the RF measurements.  This meter/sensor combination tracked the HP 435B/HP 8481A reference system to within 0.10 db worst case difference at all frequency and level measurement points.
I can only measure up to 1.3 GHz
in my shop, but using an HP 778D Dual Directional Coupler and HP 8591A spectrum analyzer.  The return loss of this sensor was >32 dB (VSWR < 1.03:1) at 1.3 GHz, well within the original HP spec of 1.30:1.  This is one of the better 10 GHz sensors I have seen - usually only an HP 8478B sensor (18 GHz sensor) will have a return loss this good.
The HP 8120-1082 5-foot
interconnecting cable is in very good shape.
The jacket is clean. I am not offering a power cord, the meter uses a standard computer cord.
Why Should You Buy This System?
As usual, here is my sales pitch:
A. It has been checked as a complete system - meter, cable and sensor. No risk of buying pieces and having one of them end up malfunctioning.
B.
It has been refurbished and checked out.
No "I can't check this out because I don't have the equipment or knowledge".
It was opened, examined for leaky capacitors, burned parts and the switches were cleaned with DeOxit.
The operation of the whole system with the sensor has been verified;  it works and is consistent with another reference system.
The sensor is not blown up, it shows good amplitude and frequency accuracy and its' Return Loss has been verified at 1.3 GHz.
C.
The system appears to be sufficiently accurate as-is for hobbyist or service work but if needed, calibration services are available from a variety of sources to bring this back to lab quality.
This is not an "AS-IS" offering!
The photos in this listing are the actual item I am offering - they are not manufacturer's stock photos, photos of a similar item or "? one kind of like this I sold last month.
"
I will ship this system by USPS with tracking and I will insure it for auction value (this is the handling cost you will see in the shipping charges).
If you have any questions, ask me!
I don't want either one of us to be surprised by something in this transaction.