Keysight V3500A RF Power Meter - Page 1
Forum section: electronics / testgear

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 15, 2025, 10:03:35 pm
content: I acquired a Keysight V3500A RF Power Meter today, and I'm very happy with it so far. It was last calibrated 10 years ago, and seems to agree quite well with my sig gen / AWGs.10MHz to 6GHz, and general accuracy is around 0.21dB, but varies by range.In photos it does look like a toy, but it's a solid piece of equipment. It's larger than it looks (banana for scale), and it's solid metal. Resist the temptation to throw it at somebody.Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: May 15, 2025, 10:19:58 pm
content: But the banana looks pretty well burned in already.

author: tautech
author_rank: Super Contributor
timestamp: May 15, 2025, 10:32:01 pm
content: Quote from: Martin72 on May 15, 2025, 10:19:58 pmSomebody exceeded 20dB !

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 15, 2025, 11:06:56 pm
content: Here's a series of photos comparing the output on the SDG2122X with the V3500A. The SDG is 5 years old (not calibrated since new), and the V3500A was last calibrated 10 years ago. Not too shabby for either of them.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 15, 2025, 11:16:42 pm
content: These photos are slightly more interesting. Directly connected, the V3500A readings look great. Once the two adapters and mediocre BNC cable are used, it loses up to 3dB compared to being directly connected.

author: Martin72
author_rank: Super Contributor
timestamp: May 16, 2025, 01:01:39 am
content: Quote from: KungFuJosh on May 15, 2025, 11:00:47 pm

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 20, 2025, 09:34:39 pm
content: Keysight support is lame.I just want a firmware update. It's not available publicly, so I started a support case on 5/16. Eventually, they gave a copypasta reply:QuoteI told them in my message the firmware version I have. They didn't tell me what the current version is or how much the upgrade service costs.I replied (still May 16th):QuoteSince then, they've passed me off to 3 different people to get an answer, and closed the case without a resolution.I still don't know what the current version is, or how much it costs.I don't know how this is considered an "A Brand."Keysight: decent hardware (when it isn't defective), questionable firmware/updates, poor support. 👎

author: d3
author_rank: Newbie
timestamp: May 20, 2025, 10:09:44 pm
content: Cool pick up, I haven't seen this device before. Do you know it's origin story? Did Keysight originally design this? The design doesn't match their other equipment, and when I searched around I also found the Keithley name on it. The design doesn't match the Keithley equipment I'm familiar with either. If it's white labeled, it might explain their resistance to field updates, but also, if it's making good power measurements, and doesn't have any issues, I'd be curious why you're pushing for a firmware update.https://www.testequipmenthq.com/datasheets/KEITHLEY-3500-Datasheet.pdfAs far as accuracy, comparing it to a calibrated power sensor, if you have access to one, would get you better numbers.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 21, 2025, 12:46:17 am
content: Quote from: d3 on May 20, 2025, 10:09:44 pmAFAIK it was originally an Agilent product. 3500 is the original version, V3500A is the newer version.I saw a couple with a Keithley sticker, and I much prefer Keithley as a company, so I was looking for those first. However, I don't know if they're real or not. Somebody might have just put a sticker on a couple for all I know. Or maybe a short-lived OEM rebrand. I couldn't find any info from Keithley about the product ever existing.Accuracy is not an issue; it works quite well. I've tested against multiple AWGs and RF sig gens. I like fresh firmware. I keep my devices updated. Not keeping your devices updated can lead to other problems.You're far too kind if you think that's why they require you to send it in for updates. It's a money grab. The only other option would be that the USB port doesn't work for the update, and a programming header is required. IMO that would be a stupid design, so I think it's less likely than money grab bullshit.Only two things would make me believe otherwise: 1. confirmation that use of a programming head is required; or 2. if they get back to me and tell me the price is $20 to cover the return shipping fees.Thanks,Josh

author: tautech
author_rank: Super Contributor
timestamp: May 21, 2025, 01:05:23 am
content: Quote from: KungFuJosh on May 21, 2025, 12:46:17 amYou might but several Siglent accessories that are USB or SBUS controlled use the connection for updating FW in those devices, so you might need the OEM models this power meter was designed to interface with to upload firmware.Been wondering how smart these power meter heads actually are as Siglent specify some HPAK units to work with the SSG range for automatic level adjustment.Never had one of these heads to test so unaware if they even could be updated via the Siglent UI.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 21, 2025, 09:14:11 pm
content: Here's some lazy cellphone teardown photos. This is a different unit that's labeled Agilent, but they're the same thing. Same 1.0.9 firmware, and both say Agilent when it starts up.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 01:49:55 am
content: Just a quick comparison. I was pleased to see the two units were generally within 0.05dB of each other. Not bad! One was last calibrated 10 years ago, and the other 5 years ago.

author: Martin72
author_rank: Super Contributor
timestamp: May 29, 2025, 06:55:43 pm
content: A good friend sent me a V3500A, thank you very much!Here are a few measurements taken with the Siglent SSG3032X generator.The collage shows frequencies of 1 GHz, 2 GHz, 3.2 GHz and levels of 0 dBm, -10, -20, -30.Further frequencies (10 MHz, 50 MHz, 100 MHz, 500 MHz) will follow.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 29, 2025, 08:14:19 pm
content: Quote from: Martin72 on May 29, 2025, 06:55:43 pmThose numbers look great! Man, it must be nice to have a well calibrated sig gen. 😉

author: tautech
author_rank: Super Contributor
timestamp: May 29, 2025, 08:42:11 pm
content: Quote from: Martin72 on May 29, 2025, 06:55:43 pmAll you need now is one of the USB RF levelling heads the SSG models support…..real handy as they can be fitted at cable load end to auto adjust the output correcting for losses.

author: Martin72
author_rank: Super Contributor
timestamp: May 29, 2025, 09:17:40 pm
content: I'm having a bit of trouble with the software right now...

author: Martin72
author_rank: Super Contributor
timestamp: May 29, 2025, 10:05:26 pm
content: I still had the SDG6052X connected, here are some (somewhat dark) images with 0dBm level, 10 MHz, 50, 100, 200, 300, and 500 MHz.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 29, 2025, 11:04:02 pm
content: I tested the SDG2122X.

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 01, 2025, 01:29:40 am
content: I received one of these units that needed repair. It was fully operational, except didn't power on with batteries. It only worked with USB or an external power supply.I made a thread in the repair section, and thankfully, I was able to help myself fix it 😉😉:https://www.eevblog.com/forum/repair/v3500a-rf-power-meter-battery-power-issue/Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: June 02, 2025, 08:46:55 pm
content: Quote from: Martin72 on May 29, 2025, 09:17:40 pmI wrote to Keysight hoping for help.Today I received a reply saying that I should first provide the name of the company and its full address before they can do anything.I don't think this is going to work...Great support.

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 02, 2025, 10:58:55 pm
content: Quote from: Martin72 on June 02, 2025, 08:46:55 pmHaving dealt with support from the biggest TE brands, I summed up my opinion in another thread:Quote from: KungFuJosh on May 30, 2025, 11:35:23 pmThat thread was only comparing those 3 brands. Tek and Keithley are the same company, and R&S is also good if you're part of a registered business. Even if you're not, I feel like they're still going to be better than Keysight. 🤦When I first got my 34465A, it took them 2 weeks to get it registered correctly in my asset list.It's been since May 15th that I opened the case with their support to get pricing for firmware upgrades and calibration for these power meters. They passed me around 5 times. Then last week somebody asked me to "Please provide the serial number of the units so our service center can reply." I have serial numbers in my asset list, and in the case I opened, but I sent them the serial numbers again anyway on the 29th. Now I'll wait again, for WTF knows how long. What kind of shitty company can't answer such basic questions? Like:what is the current version of the firmware you want to charge me to install?Keysight is like TongHui.Usuallygreat hardware, sometimes questionable firmware, and TERRIBLE customer service.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 04, 2025, 05:01:24 pm
content: I was curious about the internal rigid cable, in case it every needed to be replaced. Keysight quoted me $290.85 USD for the part.I asked them if that was for 1 or 10, but the joke was lost on them and they replied just 1. 🤣🤣

author: Martin72
author_rank: Super Contributor
timestamp: June 04, 2025, 05:07:57 pm
content: After informing Keysight that I was inquiring as a private individual, I have not heard anything back.Thank you very much, Keysight. With this attitude, you are not only alienating private customers.I, for one, will not be purchasing any Keysight products for “my” test lab at work.

author: Martin72
author_rank: Super Contributor
timestamp: June 09, 2025, 12:03:31 pm
content: Today I actually received a reply:QuoteRegarding firmware, they also wrote to me that if there is none on the website, there is no newer version available.I would have expected them to add “idiot!” to that.That's it for me and Keysight.

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 09, 2025, 02:44:40 pm
content: what a bunch of ignorant assholes.Their website says it has to be sent in to be upgraded.I like the devices but the company is painful to deal with, even as a business.

author: Martin72
author_rank: Super Contributor
timestamp: June 10, 2025, 08:27:22 pm
content: We can do without this ignorant support...

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 10, 2025, 08:52:33 pm
content: Quote from: Martin72 on June 10, 2025, 08:27:22 pmNice, you got their Virtual Panel working.Did you do it on an older computer, or did you find one that would run on Win 11?

author: Martin72
author_rank: Super Contributor
timestamp: June 10, 2025, 08:58:08 pm
content: I got it running on my Win11 notebook.Even if it's only for 30 days, I think...What you need is the VEE runtime software, which can also be the latest version (9.3), and it's free for 30 days.You also need the I/O Managing Software, which can also be the latest version and is free.From the I/O software, you extract the VESA address of the power meter and when you start the panel, you are asked which address is being used. You enter that and then it works.

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 10, 2025, 09:23:56 pm
content: Ah, looks like I missed the VEE Runtime. 🤦I already had everything else.I have the Keysight Connection Expert installed, and that lists the device there. I haven't confirmed yet, but it seems that the ASRL# is whatever the COM port is.Everything I'm using for their software was free, and the VEE Runtime didn't say anything about fees or limits of any kind.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 10, 2025, 09:44:55 pm
content: Yup, the number is always the COM port. Also, it can run multiple instances. 😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 10, 2025, 09:56:03 pm
content: I guess I never saw the article before, but they list VEE Runtime here:https://docs.keysight.com/kkbopen/how-to-use-the-virtual-panel-for-v3500a-handheld-rf-power-meter-899680266.htmlI only found that article...when I searched for VEE Runtime. 🤣

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 10, 2025, 10:34:35 pm
content: You can drag select to zoom in on the chart. Or right-click it and you can print it. I printed directly to PDF, and that's what it looked like. Not terrible, but kinda dumb. I dunno if there's a color setting anywhere to change that.I dunno if it's because I have two connected, but it's not great at controlling the device directly. You can see where I manually changed the speed and averaging in the chart.Does the Backlight button do anything for you?

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 10, 2025, 11:03:52 pm
content: Ah, I figured it out. It only sends the commands for whatever options you choose when you hit the Run key. Stop, change settings, hit Run, and it updates the settings as selected.Also, when you stop, and then hit Exit, it gives you the option to take a screenshot. I haven't found a direct screenshot option besides that yet.

author: Martin72
author_rank: Super Contributor
timestamp: June 10, 2025, 11:04:59 pm
content: This power meter panel application is intended as a demo/example and is therefore “imperfect,” but better than nothing.When it is running, only the measurement data is polled.Changes to the backlight and frequency are detected at startup.Click “Stop,” click on the backlight, then click “Start” again.Edit: Ah you got it.

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 16, 2025, 06:46:04 pm
content: This was interesting. Apparently, USB cable choice is important here. I have 2 black cables of better quality than a red cable I was using. Any meter the red cable was connected to expressed similar instability. Better cables only, and perfect stability shown.Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: June 16, 2025, 07:32:26 pm
content: WTF....

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 05, 2025, 04:09:54 am
content: These meters are really handy. I used it to confirm changes to my SMIQ06B. I went through 3 different options of the output on the SMIQ before it was good.The first attempt, there were no beads on the RF output wire I tried, and stray RF was messing with the V3500A. The zero level was unstable. I tried with a 2nd meter to make sure. Same thing- jumping all over the place.The second attempt, there were beads, but I tried to extend the original short wire, and that resulted in a 20dB loss! RF was stable, but the signal sucked.The third attempt worked great; that was the RF output line from my SML03 parts unit. It doesn't have as many beads as the SMIQ line for whatever reason, but there were no issues.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 21, 2025, 03:36:45 pm
content: It took a couple months, but I finally got an answer about the firmware. The latest version is 1.0.10, which is identical to 1.0.9 except for:QuoteI'm certainly not sending it to them for that. 🤣