Greenlee 701K-G Review: The Classic Tone and Probe Kit for Cable Tracing

Every low voltage tech needs a reliable tone and probe kit. Whether you're tracing a dead phone line through a building or identifying which CAT cable goes where in a crowded telecom closet, the right toner makes the difference between minutes and hours. The Greenlee 701K-G (now under the Tempo brand) has been an industry workhorse for years. Here's whether it still deserves a spot in your kit.

Quick Verdict

The Greenlee/Tempo 701K-G delivers solid performance for basic cable tracing at a mid-range price point around $119. The high-power 77HP-G tone generator pushes signal through longer cable runs than budget options, and the 200EP-G probe's LED proximity indicator helps identify the right pair in congested bundles. It's not the most feature-rich kit on the market—the Fluke Pro3000 offers more—but for telephone, data, and security alarm tracing, the 701K-G handles the job reliably.

Who This Is For (And Who Should Skip It)

Ideal for:

• Security and fire alarm technicians tracing low voltage circuits
• Phone/telecom installers identifying pairs in bundles
• Data cable installers who need occasional wire identification
• Anyone replacing an aging tone and probe kit with a proven performer

Skip it if:

• You need advanced features like SmartTone—look at the Fluke Pro3000
• You're on a tight budget—the Triplett Fox and Hound costs less
• You primarily trace cables through walls (signal penetration has limits)

What's in the Kit

The 701K-G includes three components:

• 77HP-G High Power Tone Generator: Creates the 890/960 Hz warbling signal that the probe detects
• 200EP-G Tone Probe Amplifier: Picks up the signal with adjustable volume and LED proximity indicator
• 700C Carrying Case: Rugged woven nylon case that keeps both units together

The generator includes red/black alligator clip leads and a four-conductor modular cord for RJ11 connections. Standard test leads cover most tracing scenarios out of the box.

Key Features That Actually Matter

High-power tone output: The 77HP-G pushes more signal than basic toners, which matters when tracing through long cable runs or bundles with significant crosstalk. In noisy environments with multiple pairs nearby, the extra power helps the probe lock onto the right signal.

LED proximity indicator: The 200EP-G probe includes an LED that brightens as you get closer to the correct wire. This visual feedback complements the audio tone and speeds up identification in dense bundles where audio alone can be ambiguous.

Adjustable volume control: The probe's volume dial lets you start quiet and increase as needed. In occupied office spaces or residential settings, cranking up a tone probe isn't always welcome. The adjustment provides flexibility.

Headset jack: A 3.5mm jack allows headphone use in extremely noisy environments or situations requiring discretion. The audio-shock protection prevents sudden loud bursts that can be jarring.

Polarity and continuity testing: Beyond tone generation, the 77HP-G can check wire polarity and perform basic continuity tests. Bi-colored LEDs display line polarity, and an audible signal indicates shorts. These diagnostic features add value beyond simple tracing.

Real-World Performance

The 701K-G performs well in its intended environment—low voltage circuits like telephone, data, and security alarm wiring. Attaching the generator to a pair and walking the building with the probe identifies the correct cable with reasonable confidence, even in bundles of 25+ pairs.

The LED proximity indicator genuinely helps. When multiple pairs carry crosstalk from the tone signal, the LED brightness differential makes the correct pair obvious even when audio signals sound similar. This feature alone justifies choosing the 701K-G over cheaper options without visual indication.

Signal strength through drywall and other obstructions is adequate but not exceptional. For tracing cables behind finished walls, results vary depending on cable depth and wall construction. It works well for cables in open ceilings and accessible raceways. For deep wall tracing, more powerful kits or different approaches may be needed.

Battery life is solid—the special power-saving feature extends run time, and techs report getting long service from a single 9V battery in each unit. The high-impact plastic housing survives typical job site handling, though the probe tip is replaceable when it inevitably wears.

One limitation: the tone generator doesn't offer as many distinct tones as the Fluke Pro3000's SmartTone technology. When tracing multiple cables simultaneously, having just one warble tone (with fast/slow selection) can slow down parallel identification. For single-cable tracing, this isn't an issue.

What I Like (Pros)

• High-power tone generator provides strong signal through longer cable runs
• LED proximity indicator brightens near correct wire for visual confirmation
• Adjustable volume and headset jack for noise-sensitive environments
• Built-in polarity and continuity testing adds diagnostic value
• Rugged nylon carrying case keeps kit organized
• Assembled in USA with CE certification
• Replaceable probe tip extends tool life

What Could Be Better (Cons)

• Limited tone selection compared to SmartTone-equipped competitors
• Signal penetration through walls is adequate but not exceptional
• At ~$119, it's more than basic kits but less than premium options
• Now listed as legacy model (Tempo rebrand)—future availability uncertain
• No filtering for AC interference in some environments
• Requires separate purchase of batteries (9V for each unit)

Specifications

Specification	Value
Model Number	701K-G
Tone Generator	77HP-G High Power
Tone Probe	200EP-G Amplifier
Tone Frequency	890/960 Hz (warble)
Tone Selection	Fast or Slow warble
Probe Gain	30 dB nominal
Probe Input Impedance	100 MΩ
Headset Jack	3.5mm stereo
Battery Life	50+ hours (probe)
Power	9V battery (each unit)
Case	700C woven nylon
Certification	CE certified

How Does the 701K-G Compare to Alternatives?

The Fluke Networks Pro3000 is the premium choice, offering SmartTone technology with five distinct tones for identifying multiple pairs simultaneously. It also boasts stronger signal transmission (up to 10 miles in ideal conditions) and better noise filtering. At roughly double the price, the Pro3000 makes sense for high-volume telecom work where the extra features save time daily.

The Klein Tools VDV500-820 offers similar functionality with five tone patterns and 1,000+ foot transmission. It's competitively priced and has strong brand recognition in the electrical trades. Klein's TONEcube technology provides comparable performance to the 701K-G.

The Triplett Fox and Hound series offers budget-friendly alternatives starting around $50-70. Build quality is surprisingly good for the price, though signal strength and probe sensitivity don't match the 701K-G. For occasional tracing, the savings may be worth the trade-off.

A Note on Branding

If the Greenlee/Tempo naming is confusing, here's the history: Progressive Electronics originally made these tools, then Greenlee Communications acquired them, and now Tempo Communications owns the product line. The 701K-G may be labeled any of these brands depending on when it was manufactured. Functionally, they're the same kit.

The Bottom Line

The Greenlee/Tempo 701K-G remains a solid mid-range choice for low voltage cable tracing. The high-power tone generator, LED proximity indicator, and built-in diagnostic features justify its price over basic kits. It won't match the Fluke Pro3000's advanced capabilities, but for security, fire alarm, and telecom work where you need reliable wire identification without breaking the budget, the 701K-G delivers.

The legacy model status is worth noting—while current stock remains available, Tempo's product line continues to evolve. If you prefer the latest hardware, check Tempo's current offerings. For proven performance at a reasonable price, the 701K-G still earns its place in the tool bag.

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