Is there any frequency selective power meter cost under $500? - Page 1
Forum section: electronics / rf-microwave

author: youta556
author_rank: Contributor
timestamp: May 23, 2022, 02:26:54 am
content: Googled `frequency selective power meter `.I get result like NARDA SRM-3006,which cost $10000+.I has ettus SDR equipment,it's not dedicated to power meter,has no absolute power value.As limit budget,is there any frequency selective power meter cost under $500?

author: dcarr
author_rank: Regular Contributor
timestamp: May 23, 2022, 03:25:42 am
content: FWIW - R&S CMU200 has this function. It's not under $500, but is a pretty useful tool overall and is way less than $10K.

author: bdunham7
author_rank: Super Contributor
timestamp: May 23, 2022, 04:36:44 am
content: Quote from: dcarr on May 23, 2022, 03:25:42 amOne warning--the CMU200 with the second RF generator option is limited to 2W (13dBm) input power, the ones without this option are good for 50W (47dBm). So shop carefully. And yes, the CMU200 seems pretty useful for the pittance (relative to the original cost) that is sells for now, even though most of its intended functionality (3G) has become obsolete.

author: RoV
author_rank: Regular Contributor
timestamp: May 23, 2022, 07:35:06 pm
content: It all depends on minimum and maximum power levels, frequencies of interest, required accuracy.The most versatile instrument to do that kind of measurement is a spectrum analyzer, with some power attenuator on the input.And, in the low end, a TinySA costs much less than 500$https://www.tinysa.org/wiki/...

author: CJay
author_rank: Super Contributor
timestamp: May 23, 2022, 07:38:35 pm
content: Quote from: bdunham7 on May 23, 2022, 04:36:44 amThe 2nd Rf generator is useful to extend the lower (and I suppose upper) limit with an external mixer but yes, the 2W limit can be a PITA though, as I'm positive you know well, a decent external attenuator is an excellent addition to the toolbox.

author: TimFox
author_rank: Super Contributor
timestamp: May 23, 2022, 07:52:02 pm
content: A good high-power attenuator is a useful investment. With a simple 50 ohm terminator on the (low-power) output port, it also serves as a high-power dummy load.

author: Stray Electron
author_rank: Super Contributor
timestamp: May 23, 2022, 11:51:19 pm
content: Quote from: youta556 on May 23, 2022, 02:26:54 amYou might take a look at the old EIP 545 and 548 Frequency Counters. IIRC they are frequency selective and a power meter was an option in them. And there are online articles telling how to add the power meter option. (I don't know if the power meter was frequency selective or just the FC portion.) Operators and repair manuals are available online.

author: radiolistener
author_rank: Super Contributor
timestamp: May 24, 2022, 12:45:54 am
content: Quote from: youta556 on May 23, 2022, 02:26:54 amIf you have signal source with known output level, you can calibrate your ettus SDR and use it as a good selective power meterFor example, you can do calibration in HDSDR on menu Options=>Calibration Settings.Just be careful and don't exceed ettus input max power. For high power measurements just add proper attenuator and add it's value to measurement result.

author: vk6zgo
author_rank: Super Contributor
timestamp: May 24, 2022, 01:29:17 am
content: "Selective millivoltmeters" were a fairly common device prior to the wider use of Spectrum Analysers.They were normally used with a 50"through load" & appropriate attenuators.Their readout was analog, & obviously, millivolts, so some calculation was necessary.Most of the ones I have seen are from R&S, but others, such as Singer, HP & possibly, Siemens, also made them.They are really ancient, now, so it's a "lucky dip".You might get a prize, or it could be a "doorstop"!

author: youta556
author_rank: Contributor
timestamp: May 27, 2022, 02:53:44 am
content: I has no experience of frequency counter,is EIP 545 and 548 Frequency Counters workable for impulse signal?

author: LM21
author_rank: Regular Contributor
timestamp: May 30, 2022, 03:30:37 pm
content: TinySa spectrum analyser costs less then 100.https://groups.io/g/tinysa

author: Stray Electron
author_rank: Super Contributor
timestamp: June 01, 2022, 12:34:09 am
content: Quote from: youta556 on May 27, 2022, 02:53:44 amI've used the EIP 545 counters but not for power measurements. They're good machines. I don't think the 545 can be used for impulse power but I think that some of the other EIP models can. Have you tried searching the internet? I know there's a good amount posted by individuals about the 545 models and the manual for it is online. I think the manuals and technical brochures for some of the other models are also online.But if you need frequency selective power measurements, you should probably get a spectrum analyzer IMO. I don't know what frequency you're looking for but I have an old Anristu MS 610 (model J IIRC) SA that has the options to measure RF power. You might look up the manual for that (the brochure, user manual and repair manual are online) and see if that will suit your needs and then look for one of those, or a newer model that has the option. Unfortunately the Anritsu manuals are pretty basic and don't tell you much beyond how to use the controls and the equipment specifications. Manuals for the HP equipment are usually much better but I don't know which models offer direct power measurement.Just as a suggestion, Hewlett Packard published hundreds of Application Notes about how to take various electrical measurements. You should look them up and see what they're published about measuring power and frequency selectivity. Many of HP's ANs are online.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: June 02, 2022, 12:19:34 pm
content: I do not know what you are attempting to measure. HF? Out of band transmission, harmonics etc...Might help if you explained what you are attempting to measure. Frequency range might be helpful.For HF, up to 30 MHz, the HP 3746 Selective Level Meter does an excellent job. Will give you Freq and Power in a narrow range.In my experience it is very accurate. Freq readout accuracy is of course limited by the oven oscillator, which is really good, if you set it carefully.This is old, heavy, big used equipment back from telephone line days. Takes a while to learn how to use it. I picked up one really cheap. Not a lot of demand. Probably cost 10K or more new.Some telephone lines carried signals in channels throughout the HF spectrum up to 30 MHz and this thing can analyze pretty much anything in those frequencies.But I do not know if you are in HF or VHF or what?A lot of Spectrum Analyzers will give you a pretty good power level for each peak and, in general this is very useful and more than adequate for most applications. Even the cheap ones can do a decent job these days. And they are good instruments for all sorts of measurements. I really think this is probably the was to go.S meters on radios are not accurate but are much better than nothing. I do not know what the standard is for your SDR but even though S meters are supposed to be "calibrated" they are very loose in their readings. One rig will not read the same as another brand and signal strength reading on the S meter will vary from band to band. Maybe the new SDR radio S meters are better, I dunno.Radiolistener seems to have done this with good results. requires calibration with an input standard, probably at the frequency of interest.S9 is supposed to be −73 dBm 50.12 pW