Have you heard the term "dummy load" but aren't sure what it is? You're not alone. The name might sound a bit misleading, but don't be fooled: a dummy load is an essential piece of test equipment for any serious radio hobbyist or ham.
They'll still be widely used in 2026. In this blog post, we'll clearly explain what a dummy load is, what it's used for, and why you should always have one in your shack.
What is a dummy load?
A dummy load is a non-inductive resistor used as a replacement for an antenna when testing or tuning a transmitter. Instead of radiating RF energy like an antenna, a dummy load converts this energy into heat.
Most radio equipment operates with an impedance of 50 ohms. A dummy load mimics this perfect load without transmitting any radio signals. Therefore, a dummy load is also called an RF termination resistor, artificial antenna, non-inductive resistor, or dummy antenna. The purpose of a dummy load? Safe testing without causing interference or damage to your system.
What do you use a dummy load for?
1. Test the transmitter without an antenna
A transmitter should never operate without a load. If it does, the power will be reflected back to the output stage. This can cause damage within seconds.
A dummy load:
- Protects your output stage from overheating
- Prevents damage due to high SWR
- Provides a stable 1:1 SWR situation
2. Measure power
Want to know if your CB radio, transceiver, or linear amplifier is delivering the correct power? You can combine a dummy load with an SWR and watt meter so you can:
- Accurately measure output power
- Modulation testing
- Checking peaks
- Optimize settings
- Without influence of antenna variables
3. Adjust without causing QRM
Without a dummy load, you radiate during testing. This means:
- Unintentional interference
- QRM for other users
- Possible complaints
Using a dummy load ensures your test remains completely "on-air silent." Professional and neat.
4. Diagnosis and troubleshooting
A dummy load is also ideal for:
- Testing coax cables
- Check antenna tuner
- Calibrate analyzer
- SWR meter testing
It creates a controlled and reproducible testing environment.
How does an RF dummy load work?
An RF dummy load usually consists of:
- A non-inductive resistor
- A suitable connector (PL-259, N-type, DIN)
- A cooling system (air, cooling fins or oil filled at high power)
The RF energy isn't transmitted but converted into heat. Therefore, a dummy load must be able to handle sufficient power.
How do you choose the right dummy load?
Choosing the right dummy load revolves around three main points:
- Power (Watts): Always choose a dummy load that can handle at least twice the output power of your transmitter or amplifier. Using a 100W transceiver? Then choose at least a 200W dummy load. A good dummy load must also be able to withstand the heat generated by the current.
For linear or high-power installations, models of 1000W or more are not an unnecessary luxury.
-
Frequency range (Hz): Check whether the frequency range is suitable for your application:
- 27 MHz (CB)
- VHF
- UHF
- Up to several GHz
The higher the frequency you operate at, the more sensitive the system becomes to small variations in resistance. Therefore, it's important that a dummy load is specifically designed for higher frequencies and doesn't contain unwanted inductance. Only then will the measurement remain reliable and you'll avoid measurement errors.
-
Connector Type: Please note the correct connection:
- UHF (PL-259)
- N-type
- DIN
This prevents you from having to use additional adapters. Each additional connection can cause small losses or deviations, which affects your measurement. With the correct connection, you'll therefore measure more accurately and reliably.
Why is a dummy load indispensable?
A dummy load isn't a luxury — it's basic equipment.
- Protects your equipment
- Prevents QRM ( unwanted interference on a frequency)
- Enables accurate testing
- Provides reliable measurement results
Both beginners and experienced radio amateurs benefit from this.
Using a dummy load with other measuring equipment
If you use a dummy load with other measuring equipment you can:
- Check SWR
- Measuring power
- Modulation tests
- Linear adjustment
Without a dummy load you risk expensive repairs, with a dummy load you work safely and professionally and prevent damage.
How do you use an SWR meter with a dummy load?
Combining an SWR meter with a dummy load is a safe and reliable way to test your installation without actually transmitting through an antenna.
A dummy load ideally has a perfect 50 ohm load. This means the SWR should theoretically be 1:1. You don't use a dummy load to measure the antenna SWR, but to check whether your measuring equipment and feed line are functioning correctly.
Do you still see a high SWR while using a dummy load? This almost always indicates a problem in:
- The coaxial cable
- The connectors
- A soldered connection
- Or the SWR meter itself
In other words, the dummy load takes the antenna out of the equation, so you are purely checking the measurement chain.
What else can you use a dummy load for?
A dummy load has several applications:
1. Adjusting older tube equipment: With older tube transmitters, a dummy load was used to correctly match the output impedance to 50 ohms.
2. Tuning modern transmitters: With modern transceivers this is usually no longer necessary, but you can use a dummy load to:
- Adjust microphone gain (mic gain)
- To test transmission power
- Check modulation settings
The big advantage: you are not actually transmitting, so you do not cause interference or unwanted signals.
How do you test if a coaxial cable (power line) is good or bad?
There are two practical methods.
Method 1: Asset Check
- Connect the transmitter to the SWR meter.
- Use a short, good patch cable to the dummy load.
- Set the meter to Forward measurement and note the maximum deflection.
Then:
- Place the coaxial cable to be tested between the meter and the dummy load.
- Recheck the forward excursion.
Judgement:
- If the reading is almost the same, the cable is probably fine.
- Is the power significantly lower? Then the cable has damping or is defective.
- Do you see reflected power? Then there's definitely a problem.
If your SWR meter has a power scale (SWR and Watt meter), you can even estimate how much loss (attenuation) the cable is causing at the test frequency.
Method 2: SWR comparison
- Connect the dummy load directly to the SWR meter.
- The SWR should be (almost) 1:1.
- Then connect the power line between the meter and the dummy load.
Interpretation:
- If the SWR remains close to 1:1, the feedline is good.
- If the SWR suddenly becomes high, then:
- The cable is damaged
- A connector is poorly fitted
- Or a solder connection is defective
Essentially, you're measuring the SWR of a known, perfect load—first without the power line and then with it. This allows you to accurately determine whether the problem lies with the cable.
Why does this method work so well?
Because you completely remove the antenna from the test. An antenna can exhibit variable behavior, but a good dummy load has a stable, known impedance.
This means you know:
Any deviation comes from the cable, connectors, or measuring equipment — not from the antenna.
In summary:
- A dummy load should almost always give an SWR of 1:1.
- Any deviation indicates a problem in the cable, connectors or meter.
- You can use this to detect both power loss and reflection.
- It is a safe way to check your installation without broadcasting.
- This makes an SWR meter combined with a dummy load a powerful diagnostic tool for any serious radio amateur.
Which transceivers is a Dummy Load suitable for?
A dummy load is suitable for virtually all transmitters and transceivers that operate with a 50-ohm output. This includes 10-meter, 11-meter (CB), and 12-meter transceivers, as well as HF, VHF, and UHF equipment. Whether you operate on the HF bands, 27 MHz, 2 meters, or 70 centimeters, as long as the power and frequency range of the dummy load match your transmitter, you can safely use it for testing, adjustment, and power measurements.
Dummy Loads available from Deltron
The table below provides an overview of the dummy loads currently available at Deltron.nl. For each model, you'll see the frequency range, (continuous) power, peak power, connection type, and the model's best-suited application. This allows you to quickly determine which dummy load is best suited for your transmitter and application.
| Model | Frequency range | Power (continuous) | Power (peak / short term) |
Connection |
Recommended for |
|---|---|---|---|---|---|
| K-PO AV-DL 200N | Up to 3.0 GHz | 35 W | 200 W (peak) | N-male | VHF/UHF, higher frequencies, measuring setups with N-connector |
| K-PO AV-DL 200M | Up to 1.0 GHz | 35 W | 200 W (peak) | UHF Male (PL-259) | CB (27 MHz), 10m/11m/12m transceivers, standard shack use |
| Moonraker DL-15N | DC – 800 MHz | 15 W (20 W CW max.) | 100 W (peak) | N-Male | Handhelds, low-power VHF/UHF tests, quick check measurements |
| Diamond DL-50N | DC – 1500 MHz | 15 W | 100 W (peak) | N-Male | VHF/UHF installations, measuring benches with N-connector |
| Diamond DL-50A | DC – 1000 MHz | 15 W | 100 W (peak) | UHF Male (PL-259) | CB radio, 10m/11m operation, standard PL connections |
| Albrecht DL20-60 | 0 – 500 MHz | 20 W | 60 W (peak) | UHF Male (PL-259) | CB, HF/VHF base stations up to medium power |
Conclusion: What is a Dummy Load and what do you use it for?
A dummy load is a 50-ohm test load that allows you to safely test and adjust your RF transmitter without transmitting radio signals. It protects your equipment, prevents interference to others, and ensures reliable measurement results.
Whether you're just starting out or have been active in the hobby for years, a good dummy load should always be in your shack.
Looking for a reliable dummy load that matches your power and frequency range? Browse the current selection at Deltron.nl and choose the model that perfectly suits your installation.
Buying Guide: Which Dummy Load Do I Need?
If you're using a 100-watt transceiver, it's best to choose a dummy load that can handle at least 200 watts. This prevents overheating and ensures safe and reliable measurements. Also, always check that the frequency range and connection match your installation.
Frequently Asked Questions About Dummy Loads
What is the difference between continuous and peak power?
Continuous power is the maximum power a dummy load can handle for extended periods. Peak power is the maximum power that can be safely handled for a short period (a few seconds). For longer test sessions, always consider continuous power.
Can I use a dummy load for CB (27 MHz)?
Yes. A dummy load is ideal for CB radios (11 meters / 27 MHz). It allows you to safely measure your power or test your transmitter without causing interference on the band.
What happens if I test without a dummy load?
If you transmit without an antenna or a dummy load, the power is reflected back to your transmitter's output stage. This can lead to overheating and permanent damage. A dummy load prevents this by safely converting the power into heat.
Should a dummy load always be 50 ohms?
For virtually all modern transceivers, yes. The standard output impedance is 50 ohms. A 50-ohm dummy load ensures a correct load and reliable measurements.
Can I use a dummy load for HF, VHF and UHF?
Yes, provided the dummy load's frequency range is suitable for your band. Therefore, always check the specifications before making a choice.
