—with examples from Keysight, Rohde & Schwarz, Anritsu and other major brands
Over the past few years, I’ve seen the same situation again and again:
An engineer sends me a few screenshots of quotes.
Their local suppliers are offering used Keysight / Rohde & Schwarz / Anritsu gear.
At the same time, they’ve found other quotes with much better prices. On paper, the deal looks great – but something feels off:
- Is the model exactly the same?
- Are any options missing?
- Is the instrument healthy, or does it have hidden issues?
- Will shipping and basic support be reliable?
Usually the message ends with:
“I really like this price, but I’m not confident enough to sign.”
I’ve been working in RF / optics / high-speed test equipment and supply chain for a long time, helping teams evaluate instruments, design setups and understand risk. In the used market, there are both genuinely good deals and a lot of “better to walk away” offers.
This article is not about generic theory.
It’s a practical checklist I personally use:
Whenever I evaluate a used RF test instrument (especially from major brands), I make sure I understand these 7 points.
You can walk through the same list for your own situation.
1. Before talking about price, be clear what you actually need to measure
A lot of conversations start like this:
“We want to buy model XXX. How much would it cost?”
After a few minutes of questions, it often turns out they just heard it’s a good instrument and haven’t really thought through what they actually need to measure.
Typical problems:
- Budget is spent on specs they’ll never use.
- Or the opposite: the datasheet looks impressive, but in the real application the instrument is not enough.
I usually start by asking a few simple questions to clarify requirements:
- What maximum frequency do you really need (in GHz)?
- Is this mainly for R&D validation, or more for production test / repair?
- Do you only need simple CW / sweep measurements, or do you need modulation analysis / EVM / BER / jitter?
- Which application family are you in: classic RF, cellular / Wi-Fi, automotive, high-speed digital, optics…?
In short:
If your requirements are fuzzy, even a “cheap” instrument can be a waste of money.
A very common real-world scenario:
- The team initially wants the latest flagship platform.
- After we clarify the actual application, an earlier generation + the right options is more than enough.
- The used market for the older platform is larger, and total cost drops significantly.
2. Are the model and options really what you think they are?
In the used market, most of the trouble hides in:
- model suffixes,
- frequency / bandwidth options,
- and software licenses.
Many quotes are extremely vague:
- Only a product family name, no exact model.
- “High configuration” or “full options” with no detailed list.
If you’re seriously considering a purchase, you need to pin down at least:
2.1 Exact model
Different suffixes within the same “family” can be a full generation apart.
Some units are older-generation platforms near end-of-life, others are current platforms with better firmware support and lower long-term maintenance risk.
2.2 Frequency range and analysis bandwidth
If the quote says “up to 26.5 GHz”, ask:
- Is this a native hardware capability, or does it rely on specific frequency-extension options?
- What analysis bandwidth is actually available?
- Is that bandwidth in the base configuration, or only unlocked by extra licenses?
2.3 Software / protocol / demodulation options
Many protocol measurements, vector signal analysis functions and standard-specific tests are implemented as software options.
You also need to know the license type:
- permanent license,
- time-limited,
- or just an old demo license that already expired.
My personal rule is very simple:
If the seller won’t provide a screen photo showing “instrument information + installed options”, or a configuration list exported from the instrument, I become very cautious.
Ideally, you get a clear screenshot showing:
- instrument model,
- serial number,
- full installed options list.
If you skip this step, further discussion about discounts is almost meaningless.
3. What is the current “health status” of the instrument?
For used equipment, “it powers on” is not enough.
You want to estimate the health of the unit as much as possible remotely, before shipment.
You can ask the seller for (serious sellers usually have no problem providing this):
3.1 Power-on photo or short video
You should see a normal boot screen with no obvious error messages.
3.2 Self-test / self-cal screenshots
Check whether self-test / self-cal passes and whether there are any serious error codes.
If there are errors, ask whether they are historical / minor, or already fixed.
3.3 Display condition
From photos you can usually spot bright lines, dark corners, burn-in, obvious color issues, etc.
3.4 Front and rear panel photos
Pay special attention to RF ports, optical ports, and coax connectors:
- Any clear dents, deformation, rust, or heavy wear?
- Many “looks okay from far away, looks scary up close” issues show up exactly here.
On calibration (cal), my view is pragmatic:
- You don’t always need a fresh third-party accredited cal.
- But it’s reasonable to ask roughly:
- when the last calibration was done, and
- whether you’ll need a new local calibration based on your project and your company’s quality requirements.
If the unit is expensive, you can also ask the seller:
- whether they can do a simple functional check and send a few measurement screenshots.
It doesn’t have to be a formal cal report – but it’s still more credible than “it works fine, trust me”.
4. Is the “good price” actually reasonable?
A low price is not a problem by itself.
A price that is suspiciously low can be.
Used prices are influenced by several factors:
- age / serial number range,
- options installed,
- cosmetic condition and usage level,
- whether it has been repaired (and how well),
- whether it comes with any cal or basic warranty,
- current market demand (some models are hot, some are cold).
You might not know the exact “market median price”, but you can still do a rough sanity check:
- For similar configurations, if one quote is much lower than others (say 20–30% lower) and the seller cannot explain why, that’s a red flag.
- If the only explanation is “clearance”, “crazy discount”, “don’t ask, just take it”, I’d suggest extra caution.
A simple way to frame it:
“Reasonable cheapness” comes from age, options and channels.
“Mystery cheapness” usually means missing information – or something else waiting down the road.
5. Is the seller just flipping boxes, or do they actually understand test & measurement?
There are many used equipment sellers out there, with very different levels of expertise.
Roughly speaking, you’ll meet two types:
5.1 Pure traders
They sell everything: machine tools, servers, instruments…
Their understanding of a specific model is mostly from spec sheets and price lists.
5.2 T&M-focused sellers
They’ve been dealing with test instruments for years. Most of their daily contacts are engineers, labs and R&D teams.
You can get a first feeling just by talking to them:
When you ask:
- “What’s the difference between this model and that model?”
- “My application is X, is this configuration enough?”
Do they just read back specs, or can they explain practical differences in real use?
You can also watch for a few small signals:
- Will they proactively tell you:
- “For your application, you probably don’t need such a high frequency / bandwidth. You could save some budget with another configuration.”
- For certain models, will they warn you instead of pushing hard:
- “This series is difficult to service now; spare parts are rare, long-term maintenance may be costly.”
Don’t be afraid to ask a few technical questions.
Sellers who regularly work with engineers usually prefer that you describe your use case clearly – it reduces misunderstandings later.
6. Shipping, packing and basic after-sales – what’s worth clarifying up front?
This section is not meant to be a legal contract.
Think of it as a list of topics worth asking the seller about in advance.
Policies differ between sellers; you can negotiate based on the project’s importance and budget.
You may want to clarify at least:
6.1 Packing
- How will the instrument be packed?
- Proper-size carton + thick foam?
- For heavy or bulky instruments, a wooden crate / extra reinforcement?
- Is there sufficient padding around the instrument to protect it from shocks?
You can simply ask:
“Before shipping, could you take a few photos of the fully packed unit for my records?”
6.2 Shipping method
- International express or air freight + local delivery?
- Will there be shipping insurance? If yes, roughly what coverage?
- Will they provide tracking information?
These questions are not complicated, but the answers tell you whether the seller has a standard process and cares about logistics.
6.3 If there is a serious problem on arrival, what are the options?
You don’t need a perfect, fixed template here, but you can discuss scenarios like:
- Within how many days after delivery can you report a major functional defect and ask for help?
- Possible options: troubleshooting and repair, partial refund, replacement, return, etc.
- In different scenarios, how might shipping costs be shared?
- For larger units, is there a practical process for returns or replacements if needed?
You can treat these as talking points, adjusted to the size and importance of each deal.
Internally, it’s also a good idea to prepare a simple receiving checklist:
- Instrument arrives → power up → run basic self-test / quick measurements.
- If there’s an issue, take photos / video immediately and then contact the seller.
7. My own “minimum checklist”
Whether or not a purchase actually goes through, when I help others evaluate a used instrument, I at least check these items:
Model + options
A screen photo showing “system information + options”, or a configuration list exported from the instrument.Power-on + self-test status
I want to see a normal boot screen at least once, and ideally one screenshot of self-test / self-cal results.Front and rear panel condition
Especially RF ports, optical ports and connectors: any clear damage, bending, corrosion?Basic seller background
Do they work with test instruments regularly? Are they used to discussing applications with engineers, or do they only talk about price?Overall direction for shipping & basic after-sales
Rough idea of how the unit will be packed, rough idea of the acceptance period after delivery, and what kinds of solutions might be on the table if something goes seriously wrong.
You can turn these 5 points into your own “minimum checklist”.
You don’t have to hit 100% ideal conditions every time – but the more you clarify up front, the fewer surprises you’ll have later.
Summary – these 7 points bring uncertainty forward, instead of leaving it for later
Buying used RF test equipment can save a lot of budget.
It also comes with information gaps, communication overhead and risk.
The 7 points in this article are meant as an engineer’s checklist:
- Be clear about what you actually need to measure, instead of chasing model names.
- Confirm the exact model and options.
- Estimate the instrument’s health as much as you can, remotely.
- Decide whether the price is reasonably cheap or suspiciously cheap.
- Judge whether the seller is just flipping boxes or actually understands T&M.
- Clarify shipping, packing and basic after-sales expectations up front.
- Build your own minimum confirmation checklist.
If you already have one or two quotes on your desk…
Here’s how you can organize them before asking for a second opinion:
- For each instrument: the exact model + option list.
- Any photos / self-test screenshots the seller provided.
- A short description of your application and rough budget.
If you send this information over, I can look at it from a test-and-supply-chain perspective and give you at least a rough comment:
- “This one looks OK to keep negotiating on price / terms,” or
- “This one is missing key information – ask a few more questions before you decide.”
About me & how to reach out
I work on RF / optical / high-speed test setups and instrument supply chain, familiar with mainstream instrument brands as well as used gear, lab services and rental options.
Most of my work is helping teams find a realistic balance between performance and budget.
- Website: https://maronlabs.com
- Email: contact@maronlabs.com
If you’re evaluating a few instruments right now, or trying to build a “good enough” test setup under budget constraints, feel free to reach out with your models and use cases.
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