Surecom SW-33 Plus SWR Meter Review: The Miniature Giant

The Surecom SW 33 Plus is a nicely low cost SWR meter aimed at being used with handheld V/UHF transceivers for amateur radio, GMRS, etc, but how does it work out - is it a low cost rubbish or a very useful instrument that has been thoughtfully designed?

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The Surecom SW-33 Plus, a device that has carved out a unique niche in the world of amateur radio and commercial communications.

If you have ever tried to measure the SWR of a handheld radio (HT) using a traditional "needle-and-box" meter, you know the frustration of adapters, cable loss, and bulky setups, especially when you are out in the car or portable somewhere. The SW-33 Plus aims to solve that problem.

However, often size often correlates with capability. Large base stations have the best filters; massive Yagi antennas have the most gain. But for test equipment, portability is often king.

At first glance, it might not be recognised as a V/UHF SWR meter, but can it live up to the expectations. I put the device though its paces having bought one to look at the SWR of an antenna I use out and about with my TIDRADIO H# and Nagoya UT-106UV antenna. SO what will my thoughts be - read on to find out . . . . .

What's in the box and first impressions

The box is an eye-catching orange, and inside you find the meter and all the accessories There's actually quite a number of small items on top of the meter itself.

SW-33 Plus meter itself
Dummy load
SMA Male to SMA male adaptor
Bag of three other adaptors: SMA female to SMA male, SMA male to BNC male, SMA male to BNC female
USB charging adapter (USB-A connector)
USB -A to USB-micro short lead
Instruction sheet

SURECOM SW-33Plus 100W Mini Power & SWR Meter 125-525MHz

Covering the main VHF and UHF amateur radio bands, this mini SWR meter comes with SMA connectors and a convenient adapter set to enable it to be connected to most handheld transceiver when using them with an external antenna. An ideal addition for your portable or mobile operating.

Buy Now

When you unbox the SW-33 Plus, the first thing that strikes you is the form factor. Measuring roughly 25 x 25 x 60 mm, it is genuinely tiny. Unlike its older sibling, the SW-102 (which is shaped like a traditional meter), the SW-33 Plus is a vertical "inline" stick.

The build quality is surprisingly robust. It features a metal chassis that provides both durability and necessary RF shielding. This is a significant upgrade over the cheaper, plastic-housed meters often found in the "budget" category. The weight is approximately 160g, giving it a "dense" feel that suggests it can survive a tumble from a workbench or a messy "go-bag."

The unit features a clear display - although the documentation I received said the display was LCD, the display I had was a crisp and clear LED display which is much better for viewing at all angles and in the dark.

One of the most thoughtful design features is the screen rotation. By tapping the single red button, you can flip the display 90 or 180 degrees. If you’ve ever had to crane your neck to read a meter because your radio’s antenna port is at an awkward angle, you will immediately appreciate this.

Technical Specifications: What’s Under the Hood?

The Surecom SW-33 Plus offers a good technical specification as seen from the table below - this has been taken directly fromt he instruction sheet which was supplied.

Specification Summary for the Surecom SW 33 Plus SWR Meter
Parameter	Specification Figures
Power range	0.1 - 120W
VSWR	1.00:1 - 19.9:1
SWR detection sensitivity	≥ 3W
Frequency Range	125 - 525 MHz
Battery	Internal Li-ion battery 3.7V 500mAh
Power In	5V micro-USB
Input / output impedance	50 Ω
Size (not including sockets)	25 x 25 x 60mm
Weight	160g

It seems a bit of a shame that in a world now dominated by USB-C, the SW-33 Plus has a micro-USB to charge the battery, but no matter the charger and lead were supplied in case there isnt one already available.

Surecom SW 30 Plus SWR meter connected to TIDRADIO HT and Supplied Dummy Load

The "Plus" Advantage: Why This Version?

The "Plus" designation means something apart fromt he marketing naming. Compared to the older SW-33 Mark II, the Plus model introduces several refinements:

Direct Readout: It provides simultaneous digital readouts for Forward Power, Reflected Power, and SWR. No calibration knobs or "SET" positions required.
Increased Power Limit: The Plus handles up to 100W, whereas some earlier mini-meters were capped much lower.
Comprehensive Kit: Most retailers ship the SW-33 Plus with a treasure trove of adapters: SMA-to-BNC, SMA-to-SMA, and even a small 5W dummy load for testing your radio's output without radiating.

In use

The SW-33Plus is a really easy item to use. It is small and convenient, yet robust so that you can take it anywhere.

I had intended to use it to check on the performance of a mobile antenna - here it easily slots into the line and does not require a large SWR meter to be carried, and as it has SMA connectors on either end, it can just slot into the line with no problem.

When you are in a vehicle (stationary) or portable you don't want a large cumbersome meter and this fits the bill very well.

The operation is also very simple: the interface is a "one-button" affair, which is great.

Long Press: Power ON/OFF.
Short Press: Cycles through display modes (SWR, Power, Screen Rotation).

You do need to be careful to get the long and short presses right, but with a little use, this is not an issue.

The interface is incredibly intuitive. You don't need a manual to figure out how to get a reading. Within three seconds of keying the mic, you have your SWR and wattage.

However, the menu system for advanced calibration (accessible on some versions by holding buttons during power-up) is cryptic and generally best left alone for the average user.

Pros and Cons

It's worth balancing the advantages and disadvantages of this SWR meter.

The Pros:

Extreme Portability: It fits in a shirt pocket.
No Calibration Needed: Just plug and play.
OLED Display: Easy to read in all lighting conditions.
Value: It usually retails for well under $50 USD or so, including the adapter kit.
Wide Frequency Coverage: 125-525 MHz covers almost everything the average handheld user needs.

The Cons:

Not for Digital (DMR): Like many digital SWR meters in this price bracket, it struggles with the pulsing nature of TDMA (DMR) signals. It works perfectly for FM, but for DMR, the power readings will be inaccurate.
Micro-USB: We are ready for USB-C, Surecom!
Sensitivity: As mentioned, hand capacitance can shift readings, requiring a bit of technique to get consistent results.

Who is this for?

The Surecom SW-33 Plus is not a lab-grade instrument (much as the box says it is professional equipment) designed for calibrating multi-thousand-dollar repeaters. It is a straightforward and very useful budget field tool.

So who would find this instrument useful:

Radio Hams: If you just bought your first Baofeng or Yaesu and want to know if your "Nagoya" antenna is a genuine upgrade or a fake, this is the tool for you.
The GMRS/MURS Users: For those using radios for work or off-roading, it’s a quick way to ensure your antenna didn't get damaged on the trail.
The Antenna Builders: If you like building "tape measure Yagis" or J-poles, the SW-33 Plus is a lightweight way to tune your creations in the backyard.

Final Verdict

The Surecom SW-33 Plus works well, especially for its cost and size. It has been described as a triumph of utility over complexity.

It doesn't try to be an antenna analyzer (like a NanoVNA), and it doesn't try to be a bench-top power meter. Instead it is a specialized, quite rugged, and highly portable device that tells you two things very quickly: how much power is leaving your radio, and how much is coming back?

For the price of a couple of pizza deliveries, you get a device that could save your radio’s final transistors from a "dead short" antenna or help you squeeze that extra half-mile of range out of a perfectly tuned whip. It lets you know what is going on at your radio / feeder interface in a very easy fashion.

Overall it is a great device which you can't beat for the money, but it's a shame about the USB micro charging connector in today's world.

Note: When using the SW-33 Plus with high-power mobile rigs (50W+), ensure your connections are tight. At 100W, even a small amount of resistance in an SMA adapter can generate significant heat, but this is the same for an SMA connector on any device.