In horizontal directional drilling, your locating system is the one thing that cannot go down in the middle of a bore. When the signal from the drill head disappears or becomes unstable, production stops, risk goes up and everyone is suddenly waiting on one small piece of hardware. For many contractors around the world, that hardware is a DigiTrak transmitter, usually called a sonde.
The SE line is one of the classic DigiTrak systems. It is simple, proven and still used on a huge number of rigs. In this guide we will look at how DigiTrak sondes work, what is special about the SE platform, how to choose the right transmitter for your rig and how to keep your sondes alive as long as possible. Along the way we will also show where a dedicated DigiTrak SE Sonde or a broader range of DigiTrak Transmitters (Sondes) makes the most sense in your fleet.
How DigiTrak sondes fit into your HDD setup
Every DigiTrak guidance system is built around the same basic idea. You have three key components working together:
- A transmitter sonde inside the drill head.
- A handheld receiver or locator that tracks the signal from the surface.
- Often a remote display in the drill cab so the operator sees what the locator man sees.
The sonde in the drill head sends a coded electromagnetic signal through the ground at a defined frequency. The receiver measures this field and calculates important data for the crew. Depth, drill head pitch, roll, temperature and sometimes direction or warnings are all derived from that signal.
If the transmitter is weak, damaged or unstable, everything that depends on it becomes less reliable. You may see jumping depth readings, intermittent signal loss or incorrect pitch. That is why a solid inventory of working sondes is just as critical as having a good drill rig.
What makes the DigiTrak SE platform different
DigiTrak SE belongs to an earlier generation of DCI equipment, but it remains popular because it is robust and straightforward to use. Instead of wideband multirange frequencies, SE relies on a well known fixed frequency that many drillers are comfortable with.
For small and medium utility projects this has a few practical advantages:
- Crews who have used SE systems for years know the signal behavior very well.
- Training new people is easier because there are fewer advanced options to confuse them.
- Replacement sondes are widely available and comparatively affordable, especially if you do not mind refurbished hardware.
However, the SE locator is only as useful as the transmitters you pair with it. Without a healthy stock of compatible sondes your system is constantly one failure away from losing a day of work.
Types of DigiTrak transmitters you will see in the field
When people talk about โa DigiTrak sondeโ, they often mean very different devices. The DigiTrak family covers a range of systems and transmitters. In daily work you are likely to come across:
- SE sondes that are matched to the SE locator.
- F series sondes for F2 and F5 systems.
- Wideband Falcon sondes for Falcon F1, F2 and F5 type receivers.
- Older Mark and Eclipse transmitters that are still in use on some rigs.
Each system has its own compatibility rules. A Falcon wideband transmitter will not behave correctly on an SE receiver, and an SE specific sonde is not intended for Falcon.
This is where it is useful to think in two layers:
- Platform specific sondes, like a dedicated SE transmitter for a crew that still runs SE daily.
- A mixed pool of DigiTrak Transmitters (Sondes) for newer rigs and more challenging conditions, for example Falcon or F5 systems that work at varying depths and in noisy urban environments.
If you understand which rigs you have and what type of work each rig does, you can design a sonde inventory that covers everything without overspending on models you rarely use.
How to choose the right DigiTrak SE Sonde
If you are specifically looking at SE hardware, choosing a sonde is usually simpler than choosing a wideband transmitter but there are still a few things to check.
Key points to consider:
- Compatibility
Make sure the sonde is explicitly designed for the SE locator. Do not assume that โany DigiTrak transmitterโ will work. - Depth and soil conditions
Standard SE sondes are intended for typical utility depths. If you frequently push close to the limit, it can be worth running a newer system on those particular jobs and keeping the SE for lighter work. - Housing size and thread
Check the length and diameter of the sonde and the housing you plan to use. A mismatch here can cause mechanical stress or make it impossible to assemble the head correctly. - New or refurbished
Many crews find that a refurbished DigiTrak SE Sonde with a real test report and warranty gives almost the same performance as a brand new unit but at a lower cost.
When you standardize on one or two SE sonde models, it becomes easier to stock spare batteries, o rings and caps, and training your people is faster because they see the same hardware on multiple rigs.
When to look beyond SE to other DigiTrak Transmitters (Sondes)
There are situations where SE, while reliable, is not the perfect fit. This is where the broader world of DigiTrak Transmitters (Sondes) becomes interesting.
You may benefit from Falcon or later F series transmitters if:
- You often drill in high interference areas with heavy power infrastructure or dense rebar.
- Your bores are longer and deeper, pushing past what a classic SE setup comfortably supports.
- You need more flexibility in choosing frequencies in the field to avoid interference.
- You want richer data and features, for example more detailed feedback on the remote display in the rig.
Upgrading one crew to a newer receiver and wideband sondes does not mean you must retire SE completely. A common strategy is to keep SE as a backup or use it on simpler bores, while directing harder jobs to the newer system.
New versus refurbished DigiTrak sondes
For any DigiTrak platform, including SE, you will find three broad categories in the market:
- Completely new transmitters from the manufacturer.
- Professionally refurbished sondes with testing, documented specs and a warranty.
- Raw used sondes with unknown history and no testing.
In most cases the third category is a gamble that costs more in downtime than it saves in purchase price. The first category is reliable but expensive, especially when you need multiple backup units.
Professionally refurbished DigiTrak sondes sit in the sweet spot. A good refurbisher will pressure test seals, verify signal strength, check depth and pitch readings and replace worn components before selling the unit. For SE systems that you intend to run for several more years, this is often the most economical way to maintain a strong pool of transmitters without overspending.
Practical tips to extend the life of your sondes
Regardless of whether you run SE or a newer DigiTrak system, small habits have a big impact on transmitter lifespan. Some practical rules that pay off:
- Always test the sonde in the housing before starting a bore, not just in the air.
- Inspect and clean o rings, threads and battery contacts. Dirt and damaged seals are a common cause of failure.
- Do not leave transmitters loaded in the head with batteries installed for long periods between jobs. Remove batteries for storage.
- Avoid extreme temperature exposure in locked trucks or containers.
- Train every locator and driller to recognize early signs of trouble, such as drifting depth readings, unusual noise in the signal or intermittent loss of data.
These habits take minutes but can save hours of troubleshooting on the job.
Building a smart transmitter strategy for your company
For a small company with one rig it is tempting to think in terms of โone locator, one sondeโ. In reality, that is risky. Even a tough DigiTrak SE Sonde can fail or be damaged if the head hits unexpected rock, if the housing floods or if batteries are not handled correctly.
A better way to think about sondes is as a pool of critical spares that protects your production schedule. Look at:
- How many rigs you operate.
- Which systems they use, SE or newer Falcon or F series.
- What kind of ground and interference you typically encounter.
- How much each lost day on a job actually costs you.
Then build a mixed inventory of DigiTrak Transmitters (Sondes) that covers your platforms and gives every crew at least one backup. Combine new and refurbished units in a way that matches your budget and risk tolerance.
If you do this once, review it once or twice a year and train your people to care for the hardware, your locating gear stops being a weak point and becomes a quiet strength of your HDD operation.
