HP 432A Power Meter HP 478A 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 1848A194xx ), HP 478A Coaxial Thermistor Mount (S/N 131xx) and an HP 8120-1082 5-foot
interconnecting cable.
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 a Return Loss of greater than 27dB at 1.3 GHz and has a calibration factor of 97% at 50 MHZ and 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.
My test and calibration 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 the
Bakelite
type plastic
type-N connector.
The RF connector is in good shape - no dings or nicks either on the shield or the center pin.
The rubber gasket is intact at the internal connector shell interface.
The 6-pin output connector is in perfect shape.
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 calibration 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 0.08 dB worst case difference at all frequency and level measurement points.
I can only measure up to 1.3 GHz
in my shop. Using an HP 778D Dual Directional Coupler and HP 8591A spectrum analyzer, the return loss of this sensor was >27 dB (VSWR < 1.07:1) at 1.3 GHz, within the original HP spec of 1.30:1.
The HP 8120-1082 5-foot
interconnecting cable is in  good shape.
The jacket is clean, but there are some splits at the cable-connector interface sleeves.  You can see these in the attached photos. I am not offering a power cord, the meter uses a standard power 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 disclaimer of  "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 HP 478A sensor is not blown up, it shows good amplitude and frequency accuracy and its' Return Loss has been verified at 1.3GHz.
C.  This meter is as clean as any meter I've had come through the shop.  As an aside, every HP 432A/HP 478A drifts on the - 20 dBm scale.  This meter/sensor pair (once they
temperature stabilize) drifts only about 1 % (half of a meter division
) in a 10-second period - one of the lowest drift rates I've seen.
D.
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.
"
NOTE:  I will not accept returns for "Buyer Regret"; I will only accept returns if the item has been misrepresented.  I will not accept a return for a blown up sensor or if the Calibration Seal on any item has been broken.
I  will ship this system by USPS with tracking and I will insure it for auction value (this is part of 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.