I manage purchasing for a 120-person engineering firm, so when our RF lead asked me to quote an Anritsu S331L and an Anritsu 68369B, I made an assumption: they were probably two versions of the same thing. They are not. One is a handheld field tester. The other is a heavy benchtop signal generator. They just happen to share the same brand name.
According to Anritsu Corp.'s product documentation, the Anritsu S331L is part of the Site Master family—a handheld cable and antenna analyzer built for field work. It measures return loss, VSWR, cable loss, and distance-to-fault. The Anritsu 68369B, from the legacy Wiltron/Anritsu line, is a synthesized signal generator that covers microwave frequencies and is designed to sit on a lab bench. You use it to produce a known RF signal, not to measure a tower feed line.
So this comparison is less about which one is better and more about which one fits the work you're actually doing. I'm going to compare them the way I had to learn: portability, function, and true cost.
There's no contest here, and honestly, this is where you'll see the design philosophy difference immediately.
The Anritsu S331L is portable. It's a handheld instrument that fits in a field carry case. An engineer can take it up a tower, into a cramped utility room, or out to a cell site. That's its whole reason for existing. The S331L is meant to be the tool you carry to the problem.
The Anritsu 68369B is not portable. It's a benchtop unit that will take up real estate in your lab and make you think hard about whether you have enough rack space. It's heavy. It needs power. It's not built for a backpack, and you'd be doing yourself a favor if you put it on a cart before moving it anywhere.
But here's the counterintuitive part: that doesn't make the 68369B worse. It means it's the right tool for a completely different job. If you never leave the lab, portability is irrelevant. If your work is all field verification, the S331L wins flat out.
This is the dimension that matters most, and it's the one I almost got wrong.
The Anritsu S331L is an analyzer. It sends a signal down a cable or antenna system and measures what comes back. That's how it finds bad connectors, water ingress, crushed coax, or poor return loss. If you're maintaining a radio site, this is the tool that tells you whether the feed line is healthy before you climb the tower.
The Anritsu 68369B is a signal generator. It doesn't analyze—it produces. You use it to create a precise RF signal to feed into a device under test. It's the kind of instrument you see in receiver testing, amplifier characterization, or EMC test setups. It gives you a known input so you can measure how the device responds.
Putting the S331L against the 68369B on a spec sheet is like comparing a thermometer to an oven. They're both tools that deal with temperature, but you wouldn't bake a cake with a thermometer.
So ask yourself what the instrument will do all day. If the answer is “verify cable and antenna systems,” the S331L is your unit. If the answer is “generate a stable, wideband RF signal for bench testing,” the 68369B is the right animal. And if someone tells you one can replace the other, they're probably trying to sell you something.
Now we get to my favorite subject: money. And this is where I have opinions.
A used Anritsu 68369B can look like a great deal on the second-user market. Depending on age, options, and condition, decent listings can sit in the $3,000–$6,000 range. But a bargain signal generator can turn into a money pit if it needs calibration, repairs, or a new interface card. I've seen that happen.
I still kick myself for one purchase. We bought a unit at a great price, and I didn't ask about the freight cost. Turned out the crate was heavy, oversized, and the shipping bill added roughly $380 to the total. That was my mistake. Now I ask every vendor two questions before any PO: “What's included?” and “What's NOT included?”
“The vendor who answers the second question before you ask it is the one worth keeping.”
With both the Anritsu S331L and the Anritsu 68369B, the quoted price is only the beginning. You need to know:
To be fair, transparent pricing isn't always the lowest number on the first quote. But in my experience, the vendor who lists everything upfront—even when the total looks higher—usually costs less at the end. The vendor who hides fees behind a low base price is a red flag, not a deal.
So what is Anritsu doing now? Anritsu Corp. has shifted much of its current product focus toward 5G, 6G research, mmWave, optical networks, and IoT test solutions. The Anritsu 68369B is a legacy product. It's still found in thousands of labs because signal generators age well, but you won't see it front-and-center on the current product pages.
The Anritsu S331L, on the other hand, comes from a product family that's still very relevant. Site Master handheld analyzers remain common in field testing, and newer generations have added more frequency range and software options. That doesn't make the S331L useless—it just means you should check what the current support and calibration situation looks like before buying one in 2025.
One more thing about model numbers: search for “Anritsu 3310” and you'll get a mixed bag of vintage and modern listings. It's easy to confuse an older model with a newer one. Always match the exact model number, options, and calibration status on the quote to the actual hardware sitting in front of you. Don't rely on the part number alone.
Here's the short version:
If you're a field engineer or tower contractor, the Anritsu S331L is the no-brainer. It's built for cable and antenna analysis, it travels well, and it answers the question: “Is this feed line healthy?” That's a job you can't easily do with a benchtop signal generator.
If you're running a lab and you need a known RF signal source, the Anritsu 68369B is the right tool. It's not portable, but it doesn't need to be. It belongs on a bench with a warm-up period before it goes to work.
If you're a generalist engineering company, you might eventually need both. They aren't substitutes. They're two separate tools that happen to share a brand name.
And if you're the person signing the PO—like me—ask the engineer to write the job requirement in one sentence. That sentence will tell you exactly which Anritsu to order. Don't let anyone talk you into a cheaper alternative that doesn't do the job, and don't pay a premium for a box that's overkill. The cheapest instrument is the one that solves the actual problem.
Pricing I've mentioned here is ballpark, based on quotes and listings I've seen over the past couple of years. Verify current rates, calibration costs, and lead times with your vendor before you commit. And ask about the freight. Trust me.