Notch Metal Detector: Breakthrough Essential Techniques

The notch metal detector function is a powerful tool allowing you to selectively reject specific VDI numbers (Target IDs) corresponding to unwanted trash targets like aluminum pull tabs or rusty nails, dramatically improving your efficiency in high-trash areas while ensuring you still hear desirable items like coins and relics.

Metal detecting is a rewarding hobby. Yet, the constant stream of trash signals can quickly ruin a perfect day. Digging bottle caps, rusty nails, and aluminum foil wastes time and energy. Many detectorists rely on the Discrimination setting to filter out junk. But Discrimination often cuts off large sections of the VDI scale. This means you might miss good targets hiding near trash. The specialized notch metal detector feature offers a precise solution. It lets you surgically remove only the worst offenders. Mastering this technique transforms your detecting success. I will show you exactly how to use this advanced tool.

Understanding the Power of the Notch Metal Detector Function

The notch feature provides surgical precision in target rejection. It allows detectorists to specifically ignore narrow ranges of Target ID numbers. These ID numbers are often linked to common trash items. For example, a pull tab might consistently register between 18 and 22. Instead of rejecting everything below 30, you only reject 18 to 22. This keeps signals like thin gold rings (which often appear below 30) audible. Using the notch feature saves time and reduces digging fatigue significantly.

Most modern detectors use a Visual Display Indicator (VDI) scale. This scale runs from 0 to 99. Lower numbers usually mean iron or low conductivity items. Higher numbers indicate silver or large copper items. The notch function lets you create “holes” in this audible spectrum. You only hear signals outside of these notched-out ranges.

How Notching Differs from Standard Discrimination

Many beginners confuse Notching with Discrimination. Standard Discrimination is a broad filter. If you set Discrimination to 30, the machine silences all targets from 0 up to 29. This is a wide, sweeping rejection. It is effective for beginners but lacks nuance.

Notching, however, is highly specific. It targets small, isolated ranges. You can notch out 18–22, but still accept 1–17 and 23–99. This allows you to hunt in areas filled with specific trash, like beaches with many bottle caps. You reject only the cap signals, keeping everything else active.

Notch vs. Discrimination: Knowing the Critical Difference

Understanding this difference is key to advanced detecting. Discrimination is a cutoff point. It filters targets based on a minimum acceptance level. Notching is selective rejection within the accepted range. You are choosing which specific target IDs to silence.

For example, I hunt an old park full of iron and modern pull tabs. If I use broad Discrimination, I might miss small hammered silver coins. These small coins often ring up close to pull tabs. Instead, I use the notch feature. I only notch out the known VDI ranges for aluminum trash. This keeps the low-conductivity coin signals active. This technique is often called “filtering.”

Using the notch setting allows for much finer control. It tailors the detector’s response to the specific trash you face.

The VDI Scale and Notching: Your Digital Treasure Map

The VDI (Visual Display Indicator) is the number your detector shows when it finds a target. This number represents the target’s conductivity and size. Learning the VDI scale for your specific detector model is essential. Every detector handles the scale slightly differently.

Before you use the notch metal detector setting, you must learn the “bad numbers.” Spend time detecting in a controlled area. Dig every target. Note the VDI number for every piece of trash you find.

Identifying Specific Trash VDI Numbers

Trash items have fairly consistent VDI signatures. A common aluminum soda can pull tab will usually register in a tight range. A square nail will hit a different, specific low number. By logging these numbers, you create a personalized trash map.

Foil: Typically very low, 1 to 10.
Small Iron/Nails: Often 0 to 5.
Pull Tabs (Modern): Commonly 18 to 25.
Screw Caps/Bottle Caps: Can be sporadic, often 25 to 40.

Once you know the VDI range for the specific trash plaguing your site, you can notch it out. If your park is covered in pull tabs (VDI 20–24), you notch only 20, 21, 22, 23, and 24. This leaves VDI 25 (often nickels or small relics) and VDI 19 (sometimes thin gold) active. This level of detail is what separates average detectorists from successful ones.

Step-by-Step Guide to Setting Your First Notch Profile

Setting up the notch function correctly requires patience and testing. Do not simply notch out numbers based on online forums. Test the targets in your local soil first. Soil mineralization can slightly shift VDI readings.

Here is a simple process to create an effective notch profile:

1. Select All-Metal Mode (Start Broad): Begin with no discrimination or notching. This lets you hear every signal.
2. Identify the Trash Culprit: Find and dig the most common trash item (e.g., modern pull tabs).
3. Record the VDI Range: Sweep the coil over the trash item several times. Note the lowest and highest VDI numbers it consistently displays. Let us assume it is 20 to 24.
4. Access the Notch Settings: Navigate to your detector’s discrimination or notch menu. This location varies by brand (Garrett, Minelab, Nokta Makro).
5. Apply the Notch: Manually select the VDI numbers 20, 21, 22, 23, and 24 to be rejected.
6. Test the Profile: Sweep over the trash target again. The detector should now remain silent or produce a very broken, low tone.
7. Test a Good Target: Bury a known good target (like a coin) nearby. Ensure the detector still provides a clear, high signal.

If the good target signal remains strong, your notch profile is successful. You have significantly reduced the noise from specific trash items.

Advanced Notching Techniques for Specific Hunting Styles

The way you use the notch metal detector feature should change based on what you are hunting. Coin shooting requires one approach. Relic hunting needs another. Gold prospecting often demands zero notching.

Coin Shooting: Eliminating Modern Junk

Coin shooting targets items with high, stable conductivity. These include copper pennies, clad quarters, and silver dimes. The trash that plagues coin shooters is usually aluminum tabs, screw caps, and zinc pennies (which often degrade oddly).

For dedicated coin hunting in high-traffic parks:

Aggressively Notch: You can be aggressive with modern trash VDI ranges (18–35).
Keep the Nickel Slot: Be cautious around the nickel range (usually 40–55, depending on the machine). Nickels and some gold jewelry share this conductivity range.
Focus on Consistency: Notch out numbers that produce broken, inconsistent tones. A solid, repeatable signal is usually a keeper.

Relic Hunting: Embracing the Iron

Relic hunters often seek very old items, sometimes called “thin hammered” objects or specific pieces of military hardware. These items might be low conductivity and often ring up close to iron. Using a notch function here requires extreme caution.

Avoid Notching Iron (0–10): Many valuable iron relics exist, such as cannonballs or tools. If you notch out iron, you miss history.
Use Iron Volume: Instead of notching low numbers, reduce the iron volume. You still hear the faint iron signal, but it is not deafening.
Search for High-Low Signals: Old, heavily corroded items can give a high VDI on one sweep and a low VDI on the next. Never notch out numbers that produce these jumpy, high-low signals. They are often targets hidden by iron.

Gold Prospecting: The Zero Notch Rule

Gold prospecting is the one area where the notch feature is usually best turned off. Gold nuggets, especially small ones, are low conductors. They often register VDI numbers that overlap perfectly with hot rocks, foil, and small pieces of wire.

I advise new prospectors to run in all-metal mode. If you must use discrimination, keep it extremely low. If you notch out foil (VDI 1–10), you are likely notching out tiny gold flakes or wires. The cost of digging trash is always lower than the cost of missing gold.

The Hidden Cost: When Notching Can Make You Miss Gold

This is the most critical warning for any detectorist using a notch metal detector. Using the notch function incorrectly will absolutely cause you to walk over valuable targets. This happens because of conductivity overlap.

Gold jewelry, especially thin gold chains or small rings, has very low conductivity. The VDI numbers for these items often fall directly into the range of aluminum pull tabs (18–25) or foil (5–15). If you notch out the common trash range of 18–25, you are simultaneously rejecting small gold jewelry.

For example, a modern pull tab rings up at 22. A thin 14k gold wedding band rings up at 22. If you notch 22, you miss the ring.

Minimizing Overlap Risk

To minimize this risk, employ the “two-way sweep” method. Before digging, sweep the target from 90 degrees in both directions.

Consistent VDI: If the VDI is highly consistent (e.g., 22, 22, 22) and the signal is sharp, it is likely the trash you notched out.
Jump VDI: If the VDI jumps (e.g., 22, then 25, then 30), or the signal is broken, it might be a good target masked by trash.

Always choose to dig questionable signals rather than risk missing keepers.

Mastering Trash Targets: Pull Tabs, Foil, and Iron

Effective notching relies on accurately classifying the three primary trash culprits: pull tabs, foil, and iron. Each requires a different strategic approach.

Dealing with Aluminum Pull Tabs

Pull tabs are the detectorist’s nemesis. They are consistent, numerous, and mimic small gold. Since pull tabs are conductive, they give a clear, high tone.

Step 1: Verify the exact VDI range of the tabs in your specific area.
Step 2: Use the tightest possible notch window. Notch only the five numbers (e.g., 20–24) that the tabs consistently hit.
Step 3: Do not notch out the numbers immediately surrounding that range, as those might be gold or older coins.

Handling Foil and Small Iron

Foil and small iron typically occupy the lowest VDI spectrum (0–15). These signals are often erratic or produce a low grunt.

Foil: If you are hunting coins only, you can often notch out VDI 1–10. But remember the gold risk.
Iron: Never notch out iron completely in relic hunting sites. For coin hunting, you can use the Iron Rejection setting (which is separate from Notching) to silence the lowest numbers (0–5).

If you are using a multifrequency detector, these machines handle iron better. They can often differentiate iron based on phase shift, reducing the need for aggressive notching.

Geo-Specific Notching: Adapting to Terrain and Location

The trash profile changes dramatically depending on where you are hunting. Your notch metal detector settings must be dynamic. What works in a 19th-century farm field will fail spectacularly on a 21st-century beach.

Urban Parks and Playgrounds

These areas are saturated with modern trash. They contain layers of aluminum, foil, and rusty screws.

Strategy: Aggressive notching is often required here. Focus on silencing the high-volume, modern trash items like bottle caps and pull tabs (VDI 15–40).
Caution: Be aware of overlapping modern jewelry. If you are looking for modern jewelry, lighten the notch.

Beaches and Waterlines

Beaches accumulate massive amounts of lead fishing weights, foil wrappers, and soda cans. Saltwater also affects conductivity readings.

Strategy: Identify the local lead and can numbers. Lead weights often read slightly lower than clad coins. Cans read very high. You may need to notch out VDI numbers above 85 if your machine reads large cans there.
Coil Control: Use the coil carefully. Notching large targets like whole cans (which often read high) is safer than notching small targets like pull tabs.

Historic Fields and Rural Areas

Trash here is usually older: square nails, horseshoes, and older tin cans. These items are often deep and heavily oxidized.

Strategy: Avoid notching almost entirely. Older iron signals are often crucial indicators of where structures once stood. Use audio clues (grunt/high jump) rather than relying on notching. Digging iron in these spots often leads to historic finds.

Troubleshooting Common Notch Metal Detector Errors

Even seasoned detectorists run into problems with the notch function. The two most common errors are “Silent Ground” and “Ghost Signals.”

Error 1: Silent Ground (Over-Notching)

Problem: You set the notch too aggressively. Now, the detector is silent even when sweeping over good targets you know are there. You have notched out too wide a range.
Solution: Immediately reduce your notch range. Test your machine on a known coin target (a silver dime or quarter). If the detector still misses it, switch back to all-metal mode. Then, slowly reapply only the most necessary notch points, one VDI number at a time. Always confirm the machine still hears high-value targets.

Error 2: Ghost Signals (Inconsistent Notching)

Problem: The detector gives a broken, choppy signal for a piece of trash you notched out. You are still hearing junk.
Reason: The target is either very deep, oxidized, or resting next to another piece of metal. This causes the VDI number to jump outside your notched range.
* Solution: Check your ground balance. Poor ground balance can cause VDI numbers to drift. If the target is shallow, try sweeping slowly from different angles. If the signal is jumpy and inconsistent, it often indicates a trash cluster.

Remember that no detector is perfect. Notching minimizes noise, but it does not eliminate the need for careful listening and digging confirmation.

Frequently Asked Questions (FAQ)

Is the notch feature available on all metal detectors?

No, basic entry-level detectors usually only have broad Discrimination settings. The notch feature is standard on most mid-range and advanced metal detectors. Look for models advertising multi-segment discrimination control.

Will notching out iron ruin my chances of finding relics?

Yes, almost certainly. Many valuable relics, especially military items or old tools, are made of iron or steel. Notching out iron (VDI 0–10) means you will miss these historical finds. For relic hunting, use all-metal mode with low iron volume instead of notching.

How do I know which VDI numbers to notch out?

You must perform a site survey. Dig common trash items in your hunting location and write down their VDI numbers. These numbers are specific to your machine and local soil. Never notch based only on advice from another detectorist using a different machine.

Can I notch out multiple VDI ranges at once?

Yes, most advanced notch metal detector systems allow multi-notch settings. You can reject VDI 5–8 (foil) and VDI 20–24 (pull tabs) simultaneously. This helps tackle multiple types of trash targets.

Does using the notch function affect the depth of detection?

Generally, no. The notch function is a filter for the audible signal, not a change in transmission power. However, running a highly aggressive notch profile can mask deep targets. A deep, good target might give a weak, broken signal that is easily confused with a notched trash target.

What is the best notch setting for finding gold jewelry?

The best notch setting for gold jewelry is usually zero notching. Gold jewelry often falls into the VDI range of common trash like pull tabs and foil. To maximize your chances, run in all-metal or very low discrimination mode and dig all non-ferrous signals.

Final Verdict: Mastering the Notch for Maximum Finds

The notch metal detector feature is an essential tool for serious detectorists. It allows you to transform noisy, trash-filled areas into productive hunting grounds. By selectively rejecting specific VDI numbers, you drastically cut down on digging junk. This saves your energy and keeps your focus sharp.

However, precision is paramount. Never notch blindly. Always understand the VDI range of the trash and the valuable targets you seek. Test your notch profile frequently with known good targets. Use the notch tool surgically, targeting only the worst offenders. When used correctly, the notch feature ensures you are maximizing your time finding keepers and minimizing the sound of trash. Start slow, test your settings, and watch your keeper pile grow.