Short answer: yes—but not in the way you’re probably expecting.
🚫 Off-the-shelf ham tuners: no
All the usual amateur ATUs—like
only cover roughly 1.8–30 MHz (HF). Even the “wideband” ones stop there. They simply don’t have the inductance range for 20 kHz.
⚠️ Why 20 kHz is different
At 20 kHz (VLF):
- Wavelength ≈ 15 km
- Radiation resistance is tiny
- Required inductance is huge (mH to H range)
So a conventional L/C ATU becomes:
- impractically large
- extremely high-Q (bandwidth can be a few hundred Hz or less)
That’s why you rarely see commercial “tuners” for this range.
A nice real-world observation from hobbyists:
tuning a loop at ~20 kHz can give bandwidths of only a few hundred Hz
✅ What does exist commercially
There are two categories:
1. Military / professional LF–VLF tuning systems
Companies like Kintronic Laboratories build:
- motorised variometers
- huge loading coils
- full antenna tuning networks
These are designed for tens of kW systems (e.g. 20–160 kHz)
👉 But:
- bespoke
- very large
- very expensive
2. Receive-side “tuning” (not really ATUs)
You’ll find things like:
- tuned loop antennas
- active antennas (e.g. Boni-Whip covering ~20 kHz–300 MHz)
These don’t “match” in the transmitter sense—they:
- resonate the antenna
- feed a high-impedance amplifier
3. DIY / semi-kit solutions (most realistic)
The closest thing to a practical “tuner” at 20 kHz is:
- a variometer or large loading coil + capacitor
- usually integrated into the antenna itself
Example kits exist covering down to kHz ranges (loop-based systems)
💡 Practical takeaway (for your kind of work)
At 20 kHz, instead of buying an ATU, people typically:
- Build a resonant antenna system
- large loop or long wire
- loading coil (often adjustable)
- high-voltage capacitor
- Or use:
- untuned antenna + high-Z preamp + DSP
🧠 Bottom line
- Commercial ATUs: none for 20 kHz (in the ham sense)
- Commercial solutions: only large-scale / military / bespoke
- Real-world approach: the antenna itself becomes the tuner
Note: There is one company that sells off the shelf antenna tuner for these frequencies = UK Radio Astronomy Association sells a VLF antenna tuner designed for radio astronomy work.