HP 53131A Universal Frequency Counter 225MHz 2ch Opt 001 Oven Timebase GPIB Used
Item Condition
[Guaranteed] Arrived in working condition from a development institute or research center.
We do not perform calibration, so we cannot guarantee the accuracy and precision of the unit within the calibration period.
Please purchase this item with the understanding that it is a used item.
Cosmetically there is visible damage: the rear plastic bezel has cracks and chips at two corner areas, including a crack around a screw hole, and the tilt stand (feet) is missing. The rear BNC connectors (Ext Arm / Ref In / 10MHz Out) show rust and discoloration, although they are not loose. The serial plate frame on the rear panel has no label, so the serial number, production year and country of manufacture could not be confirmed on this unit.
Operation Check
- Power: turns on normally with an IEC cord (our in-house cord was used for testing; no cord is included)
- Display: VFD is bright with no missing segments
- Basic operation: POWER / Recall / Enter / Freq & Ratio keys all respond
- Self test: TEST: ALL? executed, result ALL: PASS
- Firmware: REV 3646
- Frequency measurement Ch1: OK, measured at 10 kHz and 10 MHz
- Frequency measurement Ch2: OK, measured at 10 kHz and 10 MHz; both channels read the same signal at the same value (difference between channels only 0.5 Hz)
- Installed option: Option 001 MS Oven (medium stability oven timebase) marked as installed on the rear OPTIONS panel
- Not installed: Option 010 HS Oven, Option 012 US Oven, Channel 3 GHz input (front and rear ports plugged), Option 060 rear terminals (rear INPUTS 1/2/3 all plugged)
- Interfaces: GPIB and RS-232 connectors are fitted (communication not tested)
- Frequency accuracy reference: with our in-house signal source at 10 MHz this unit read 9,999,793.4 Hz, while our in-house HP 53181A read 9,999,835.4 Hz for the same signal (difference 42 Hz = 4.2 ppm). Our signal source itself is out of calibration, so absolute accuracy could not be judged. Results were identical immediately after power-on and after one hour of warm-up
- Not verified: absolute frequency accuracy against a traceable 10 MHz standard
- Not verified: internal 10 MHz Out loop-back test (our BNC cable was too short to reach from rear to front)
- Not verified: external reference (Ref In) lock, External Arm input, period / time interval measurement, peak voltage measurement, 50 ohm / 1 Mohm input termination values, individual self-test items, GPIB communication
- Previous owner's information: stated that the unit powers up, passes the start-up self test and that the front panel keys respond. This is their report, not our own verification
Included Items
- 1x HP 53131A universal counter main unit (INPUT 170 VA MAX / 100-120 VAC 50/60/400 Hz / 200-240 VAC 50/60 Hz, detachable IEC inlet)
- No power cord, no handle, no tilt stand, no other accessories
Please check the photos for exactly what is included.
Please check the photos for the included accessories.
Product Info
The HP (Agilent / Keysight) 53131A is a 10-digit-per-second universal frequency counter with two input channels covering DC to 225 MHz. It measures frequency, period, ratio, time interval and peak voltage, and provides GPIB and RS-232 interfaces for automated test systems.
This particular unit is fitted with Option 001, the medium stability oven-controlled timebase. It is widely used in RF and electronics labs, production test, and service benches where stable frequency measurement is required.
Specifications
| Brand | HP |
|---|---|
| MPN | 53131A |
| Model | 53131A |
| Type | Universal Frequency Counter |
| Country/Region of Manufacture | United States |
| Frequency Range | DC to 225 MHz (Channel 1 / Channel 2) |
| Number of Channels | 2 |
| Resolution | 10 digits per second |
| Timebase | Option 001 Medium Stability Oven |
| Interface | GPIB, RS-232 |
We ship worldwide from Japan by DHL / FedEx express with a tracking number on every order.
- Orders are dispatched Monday to Friday. Weekends and Japanese public holidays are not available because the carriers are closed.
- We can only ship to the address registered on eBay. If you need a different address, please update it on eBay before ordering.
- Every item is professionally packed with double-wall boxes and cushioning. Sensitive equipment is packed in anti-static material.
- We do not mark merchandise values below value or mark items as gifts. Japanese, U.S. and international regulations prohibit this.
For buyers in the United States: This item is shipped with all duties prepaid (DDP). The applicable U.S. import tariff is already included in the item price — you will not be charged any additional duties or fees upon delivery.
For buyers outside the United States: Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyer's responsibility. Please check with your country's customs office to determine what these additional costs will be prior to bidding or buying.
Important - if a DDU shipment is returned to us: When an item ships with duties unpaid (DDU), the carrier will contact you to collect import charges and any clearance documents required. Please respond promptly. If the shipment cannot be delivered and is returned to us because import charges were left unpaid, or because the carrier's requests went unanswered, eBay's Money Back Guarantee does not cover an order that could not be delivered for these reasons. In that case we will refund the item price once the returned item reaches us, less the actual round-trip shipping and any return or customs charges billed to us by the carrier (at cost, documented). Please make sure you are able to receive the shipment before buying.
Returns are accepted under the return policy shown at the top of this listing, and every order is covered by eBay Money Back Guarantee.
- If anything is wrong with your order, please message us first — we answer every message and will work with you until it is resolved.
- Any damage caused in transit should be reported within 3 days of delivery, with photos of the item and the outer box.
- Returned items must include all accessories and the original packaging.
We are a Japanese company specialising in used equipment sourced within Japan. Every unit is received, inspected and photographed by our own team in Niigata before it is listed — the photos in this listing are of the actual item you will receive.
Japanese equipment is typically kept in careful condition, and we describe exactly what we find, including any faults. If you have a question about this item or are looking for something we do not currently list, please feel free to contact us.
Inspected In-House
Checked and photographed by our own technicians before listing. What we find is what we write.
Packed for Transit
Double-wall boxes, cushioning and anti-static material for sensitive equipment.
Tracked Worldwide
DHL / FedEx express from Japan with a tracking number on every single order.