Amprobe AT-3500 Underground Cable Locator

(10 customer reviews)

  • Note: For an updated version of this underground locator, see the UAT-620
  • Locates underground energized and de-energized wires, cables and pipes
  • Three testing modes for best accuracy
    • Passive power (50/60 Hz)
    • Passive radio (RF)
    • Active T-3500 signal generator with induction mode directly connected to the cable with test leads or optional clamp
  • Active mode depth measurement up to 16’ (4.9 m)
  • Semi-automatic gain control – fast signal location and control
  • 33 kHz active frequency – best frequency for general locating
  • Precise pinpointing of buried services and exceptionally fast sound and meter response with backlight multiple-segment bar-graph digital display and audible indicators
SKU: 3435058 Category:


Keep productivity high and operational costs low, with the Amprobe AT-3500 Underground Cable Locator. It is the rugged, economical solution for locating cable, wires and pipes that are underground if they are energized or de-energized. Great for parking lot and airport lighting applications, it precisely pinpoints buried services, with exceptionally fast sound and meter response.

The backlit, multiple-segment, bar graph, digital display, plus audible indicators easily locate cables and wires. The AT-3500 Underground Cable Locator employs the proven 33 kHz frequency for most locating applications. To avoid lines at utility construction sites, it also offers the highly sensitive power and radio modes. Take depth measurements with the simple press of a button.

Additional information

Measurement Category

Locates energized/de-energized wires, cables, pipes

Passive tracing - 50/60 Hz

Passive tracing - Radio

Active Tracing

33 kHz

Active tracing - Induction mode (33kHz)

Depth measurement

Up to 16 ft (4.9 m)

Signal Clamp accessory

(optional accessory)

A-Frame accessory

(optional accessory)

Null and peak tracing options



Sonde capable

Auto display backlight sensing (Receiver)



Receiver depth range & measurement Maximum 16 ft (4.9 m)
Passive tracing frequencies 50 Hz / 60 Hz
Transmitter frequency Single, non-adjustable
Receiver active frequencies (Hz) 32.768 kHz
Receiver passive frequencies (Hz) Range 1: radio 15 kHz to 23 kHz
Range 2: power network 50 Hz / 60 Hz;
optionally 100 Hz (can be adjusted by Amprobe service personnel)
Receiver depth display accuracy Range 1: radio +/- 20 %
Range 2: power network +/- 20 %
Range 3: transmitter +/- 5 % (>5m (6-FT)),
+/- 20 % (<5m (15-FT))
Receiver antenna (distance sensitive left/right guidance)
Line ID (signal select, guidance compass, distortion alert)


AT-3500 Underground Cable and Pipe Locator System

Get an insight into the AT-3500 Underground Cable/Pipe Locator System features.

What’s Included

  • Receiver
  • Transmitter
  • Connection cables
  • Ground stake
  • Carrying case
  • Batteries (installed)


Datasheet »
Product Manual »

10 reviews for Amprobe AT-3500 Underground Cable Locator

  1. sunny2011



    ✔ Yes, I recommend this product.

  2. rcrocker1

    this product is great for finding and depth and locat for long distants

    I ‘ve used one for years locating phone and gas line and it work great . I can find and track wire or pipe and also know how deep with in a few inchs for digging and locating. It
    s great.

    ✔ Yes, I recommend this product.

  3. Handyman22

    Great product

    Easy to use, fast, great tool made job so much easier!! Use it alot! So much better than before!

    ✔ Yes, I recommend this product.

  4. Jolly

    Great tool

    Easy to use and read… used at a plant and we requested more of them to assist us in our day to help increase productivity

    ✔ Yes, I recommend this product.

  5. grumpy

    don’t waste your money

    This unit does not come ‘complete’ as advertised. The clamp is an extra charge. It will find live buried loads but It can’t be directly connected to a live load making it difficult to isolate one load in a trench with more than one load. Compared to a ‘competitor’ the Amprobe 3500 wieghs more, does less, yet cost twice as much. I have tried for 11 months to return it but niether the vendor nor the factory will respond to e-mails asking for help.

    ✘ No, I do not recommend this product

  6. Amprobe

    The complete AT-3500 kit consists of receiver, transmitter, connection cables, carrying case, instruction manual and batteries. We call this kit complete because it is sufficient to trace almost all buried utilities. The clamp-on attachment is used infrequently and it is truly an optional accessory for this tool. This is the very first time we were informed that the understanding of the complete kit may be different than what we have tried to convey. We stand behind our products and if you are unhappy for any reason, please send an email with your contact information to We will do whatever we can to meet your satisfaction.

  7. Kideo701

    Building Repair Supervivsor

    My co-worker own the Amprobe underground locator it made the job fast, clean and a lot easier. I highly recommend this tool for anyone that has to do any digging. I really felt safe for the first time in all the years of my career. Amprobe underground Locator is a tool I hope to own one day.

    ✔ Yes, I recommend this product.

  8. luppoldh

    excellent Tracer

    I use this tracer when I am investigate problems with light poles in several HOAs in the area. I am very happy with the performance of this tool. It allows me to quickly attach to the light pole and tracer out where panels are located and the directions of where the circuits are going. It has saved me countless hours. It also does excellent in finding underground power lines before I dig. This is a must to stay safe because I have caught a couple of time where 411 missed a primary feeder when I call them out to mark before I dig.
    This unit will pay for itself, companies are always looking for people to trace private lines before they dig. 811 will only trace public lines they control. The private lines like light poles, underground services to attached buildings are all easy to find with this tracer.
    It does take awhile to get the hang of. I found that sometimes using low power mode gets a better result than starting out in high power mode. You also need to pay attention on he Green Flashing Lights and the *red Green* flashing lights. You need to know the difference and what to do when the last light is green flashing, red/green flashing, and red flashing. I feel the manual did not put enough importance on those lights and what they mean.
    AS with all their tracers read the manual and practice with it. Same thing with the AT7030 when tracing wires inside you need to practice with it so you can use it confidently.

    ✔ Yes, I recommend this product.

  9. Jobin

    We are Not Satisfied at all

    Dear Sir,
    We could not use the unit until now successfully,It do not show underground cable and pipes,
    A good demonstration video also not available in your site,
    Please send to us a good training video so that we can try at least

    ✘ No, I do not recommend this product

  10. Allen

    Works great, wet dry and any temp

    Easy to.use. Simple to figure out how to use this unit. Rain, snow, hot or cold I use this at least 50X a year. My friends in other fields of work used to have me trace lines for them, and some have gotten there own. Kust buy quality tool to do good work…

    ✔ Yes, I recommend this product.

  11. Franyer

    I have an AT3500, this present a message ERR 200 and ERR 128 but I don’t find information about this.

    Please, help whit this problem.

    Thank you.

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