FS: Used HP/Agilent E4400B ESG Signal Generator (UK/EU) - Page 1
Forum section: electronics / general

author: jlake
author_rank: Contributor
timestamp: May 20, 2019, 04:09:15 pm
content: Please see myeBay listing here.HP Agilent Keysight E4400B RF Signal Generator, 250kHz - 1GHz. Condition is Used, but you can see that the operation is verifiable. Of course, it passes all self-tests. An excellent signal source! Frequency resolution of 0.01 Hz and +13 dBm to -136 dBm! Just look at the stability of the ouput frequency:250 kHz output: 250,000.000058 Hz500 kHz output: 500,000.00002 Hz50 MHz output: 50.000000000 MHzThe frequency counter values are taken with a gate time of >5 s, as per the E4400B calibration manual (just good practice). The peaks from the spectrum analyser may look rounded, but please remember that the N3920A spectrum analyzer was set to a resolution bandwidth of only 10 Hz, and a span of 100 Hz. The rounding you're seeing is NOT(!) due to the performance of the sig gen, but the poor performance of the spectrum analyzer - it'll only go to a span of 100 Hz with a RBW of 10 Hz. The power is spot on, as shown in the various images - it's shown in the top right hand corner of the spectrum analyzer's screen.Note that the crosses you see on the verification table at the end are only out by approximately -0.01 dBms. This could be due to the accuracy of my spectrum analyser, -0.01dBm is not much!This sig gen can comfortably do frequency and phase modulation, as well as amplitude and pulse modulation. You can also do step sweeps. All BNCs and the RF N-type connector are outputting, as they should be! Unfortunately, there is a small amount of damage to one of the flexible rubber carry handles on the side of the sig gen, but the handles are still sturdy and this has absolutely no effect on the operation of the equipment.I can and will remove the sticky gunk left from other stickers! Please let me know if you'd like me to remove the PAT testing stickers.The item will be securely and professionally packaged, with a UK 5A fused cable.

author: bob91343
author_rank: Super Contributor
timestamp: May 20, 2019, 04:29:49 pm
content: Nice unit but I have always wondered why one would want such great frequency resolution. I have a generator with 1 Hz resolution. I use it to test transceivers, HF and VHF and UHF. I don't find many situations where I move the frequency around in 1 Hz increments unless I am measuring the resonant frequency of a crystal.

author: jlake
author_rank: Contributor
timestamp: May 20, 2019, 05:44:33 pm
content: Quote from: bob91343 on May 20, 2019, 04:29:49 pmTrue! These are pretty high-end instruments though, with excellent stability (due to the oven controlled YIG oscillator). These are common-place in physics labs, they can be used for NMR, for example.Not *that* useful in a home lab, unless you're doing communications, radar system development, sat. comms., receiver testing, standards compliance, etc.Of course, there are, no doubt, hundreds of applications that require a very low noise local oscillator, that produces high fidelity signals with low phase noise. Most of those applications are unlikely to be undertaken in a home lab, but... you never know!

author: bob91343
author_rank: Super Contributor
timestamp: May 20, 2019, 05:51:28 pm
content: I understand. The only thing lacking in my lab is a means of generating signals compatible with cellphones. You know, the orthogonal dual signals. I don't really need it, but then I don't really need a home lab either. And a stereo signal source. I used to have one when I had my shop but left it behind. I have a little Chinese FM module for allowing an audio source to be heard in a car radio but wonder how good a signal it generates. I should check it on one of my spectrum analyzers, although measuring its separation isn't simple, and there is no means to adjust pilot level.So much to do and learn, and so little time.

author: PlainName
author_rank: Super Contributor
timestamp: May 20, 2019, 06:13:53 pm
content: QuoteBut you will set it toexactlythis figure, or that figure - you don't have to be incrementing by some resolution to want to be able to set by that resolution.QuoteMaybe because errors accumulate, and you can only get worse resolution downstream. Can't recall anyone ever complaining their kit is too accurate but plenty t'other wayedit: goes without saying that accuracy != resolution, but you're generally lumbered with the effects of the worse one.

author: bob91343
author_rank: Super Contributor
timestamp: May 20, 2019, 07:39:14 pm
content: I totally agree. I have a 6-1/2 digit voltmeter. I mean, doesn't everyone need to measure voltages to six and a half digits? My counter, unfortunately, has a time base that only goes to 10 seconds. Thus I can only resolve 0.1 Hz. For low frequencies I can measure period but for, say, 500 MHz I am stuck with only 2 ppb resolution. I calibrate it with a rubidium standard that presumably is around 100 times as accurate.This can be an obsession or at least a fetish. I am guilty.Someone gave me a box of components. After sorting it out, I see that included was a few 1N4148 diodes. Well, maybe more than a few. Well, maybe more than many. Well, perhaps several thousand. After all, one never knows when one might have need for an occasional 1000 1N4147 diodes, does one?

author: GreyWoolfe
author_rank: Unknown
timestamp: May 21, 2019, 06:57:00 pm
content: Quote from: bob91343 on May 20, 2019, 07:39:14 pmSame thing you do when someone gives you 1000 NIB 3A rocker switches. You take those and some other stuff he gave and trade them for a Metcal MX-500 without wand but with the Talon tweezers and stand.

author: bob91343
author_rank: Super Contributor
timestamp: May 21, 2019, 09:47:28 pm
content: Yes I have a big box of parts, mostly brand new resistors. Maybe 1/4 or 1/8 Watt. Each bag has around 50 pieces. It's a rather large box.It's psychologically impossible for me to throw these away. Yet, finding use for them is also impossible. I am trapped.Sometimes I pick a bag and measure the parts. Occasionally I get lucky and find some mismarked or out of tolerance and I gleefully trash them. If I have need for a short jumper wire I will sacrifice a resistor and clip a lead.There are also capacitors, mostly ceramic disk.