Okay, this sounds like a challenging problem! Here's a breakdown of strategies and tools, going beyond a standard tone tracer, for finding that buried splice box

Understanding the Problem
Shielded Cable

The shielding makes inductive tone tracing much harder. The signal might not radiate effectively.

Grease-Filled Cable

This suggests the cable is designed for direct burial and is likely very robust.

Length Differences

The difference in readings from the Ideal Linkmaster Pro is crucial. "800 feet, all pairs open" likely means the far end is completely disconnected. "T/R Network" suggests some kind of termination or impedance mismatch, hinting at a fault or connection attempt.

Missing Splice Box

The fact that the box is gone is significant. It suggests deliberate removal (vandalism, maintenance, etc.) which means the cable might have been cut, pulled, or re-routed.

Strategies and Tools Beyond Tone Tracers1. Visual Inspection & Ground Penetrating Radar (GPR) First, visual inspection

Walk the entire route between the buildings. Look for: Ground disturbances: Patches of recently dug or filled-in soil. Subtle depressions: Signs of ground settlement where a box was buried. Evidence of digging: Scratches on pavement, disturbed landscaping. Examine where the cables leave the buildings. Are they likely taking a direct route? Or is there a chance they were re-routed?

Ground Penetrating Radar (GPR)

If visual inspection fails, consider hiring a utility locating service with GPR. This technology uses radar waves to image underground objects. It's expensive, but often the most reliable way to find buried utilities, especially if they are shallow. Explain the problem and cable type clearly to the technician.2.

Advanced Cable Fault Locators (TDR and Bridge Methods) Time Domain Reflectometer (TDR)

A TDR sends a pulse down the cable and analyzes reflections. These reflections are caused by impedance changes (like cuts, shorts, or splices). TDRs provide distance to the fault. Some advanced TDRs can even "see" through shielded cables better. If you can borrow or rent a TDR, this is your best bet for pinpointing the location. Important: A TDR works best if you know the cable's velocity of propagation (VoP). This is usually a percentage. Without the VoP, your distance readings will be inaccurate. The cable manufacturer might have this information. You can sometimes estimate it, but accuracy will suffer.

Bridge Methods (Wheatstone Bridge/Murray Loop Bridge)

These older techniques are more involved but can be useful if a TDR isn't available and you suspect a short to ground. They require more expertise in electrical testing and calculation.3.

Cable Locator with Direct Connection & RF Signal (Less Effective on Shielded Cable) While you've ruled out tone tracers, some utility locators allow a direct connection to the cable. The locator injects a specific RF signal into the cable. The handheld receiver then detects this signal in the ground above the cable. While shielding will reduce the signal's range, it can still be effective, especially if the shield is damaged or corroded at the fault point. You'd need to: Connect the transmitter directly to the inner conductors of the cable at one end. Make sure the shield is properly grounded at the transmitter. Use the receiver to walk the presumed cable route, looking for the strongest signal. This can be difficult with shielded cable because of the shield blocking or reducing signal radiation.4. Capacitance Meter - Refined Interpretation You're already using a capacitance meter (the Ideal Linkmaster Pro). Here's how to use it more effectively: Document Readings Carefully

Record the exact length readings and the "T/R Network?" message for each cable. Note any fluctuations or changes as you move the cable.

Grounding

Try grounding the shield at both ends while taking readings. This can sometimes stabilize the readings and give you a more accurate length estimate to the fault.

Pair Combinations

Test capacitance between all possible wire pairs within the cable. A short between two wires will drastically change the capacitance readings.

"T/R Network?" Investigation

The "T/R Network?" message means the meter thinks it's seeing some kind of termination. Disconnect everything from the far end of the cable you're testing. Make sure there are no devices connected, even by accident. Retest. If the message persists, it strongly indicates a fault within the cable.

Comparative Readings

Take the length the meter is giving you on the faulty cable as a rough estimate to the fault. Start your search in that area.5.

Manual Digging (Last Resort) If all else fails, and you have a very good idea of the route, you might consider carefully digging small exploratory holes along the presumed path. This is risky because you could damage the cable further. Start small, and use hand tools to avoid damaging anything.

Important Considerations Safety First

Before digging anything, call your local "Call Before You Dig" service (e.g., 811 in the US). They will mark any other buried utilities in the area.

Cable Route Documentation

Check if there are any old maps, blueprints, or cable route diagrams for the campus. These could give you a significant head start.

Expert Advice

If you're still struggling, consider consulting with a telecommunications contractor or a utility locating specialist.

Troubleshooting the Linkmaster Pro Calibration

Is there a calibration procedure for the Linkmaster Pro? Check the manual. An uncalibrated meter can give inaccurate readings.

Clean Connections

Ensure that your test leads are making good contact with the cable conductors. Clean the conductors if necessary.

Cable Type Setting: Double-check that the Linkmaster Pro is set to the correct cable type (if it has such a setting).Good luck with your search! It's going to require patience and careful investigation. Let me know if you have more information or specific readings, and I'll try to provide further guidance. Flag for review