Sine Wave Source Up to 500MHz / 1GHz - Page 1
Forum section: electronics / testgear

author: FivePoint03
author_rank: Regular Contributor
timestamp: December 19, 2015, 02:49:04 pm
content: Hi guys,I am in need of a new piece of test gear. It's out of my usual area. I need to generate a variable amplitude sine wave with an upper limit about 400/500MHz, ideally a bit higher still.I don't need a full blown ARB just yet at least and they are pretty expensive at the 100MHz area anyway.Any suggestions? This little board looks like a possibility:-http://www.ebay.co.uk/itm/161768485094?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D161768485094%26_rdc%3D1I am happy to design a board if need be.Suggestions very welcome.Thanks

author: nctnico
author_rank: Super Contributor
timestamp: December 19, 2015, 03:00:47 pm
content: IMHO an RF generator would be more useful. You have to check the specifications carefully though if you need a really pure sine wave. 2nd harmonics up to -30dB are not an exception.

author: KJDS
author_rank: Super Contributor
timestamp: December 19, 2015, 03:05:53 pm
content: The easy way forwards is with an RF signal generator. There are plenty of older ones out there that stop at 1GHz with reasonable performance. A Marconi 2018 or 2019 would meet your needs for not much money.

author: FivePoint03
author_rank: Regular Contributor
timestamp: December 21, 2015, 08:17:56 pm
content: Thanks for the suggestions. After your prompts I've been looking at a Marconi 2023 and also HP 8657B. Also any comments on the HP 8644B?Just seems a lot to spend when I can't see any use past this one job, suppose I could measure my 'scope bandwidth!

author: Electro Fan
author_rank: Super Contributor
timestamp: December 21, 2015, 08:23:57 pm
content: The Marconi 2018 and 2019 look like potential candidates. If you want to stay in the HP/Agilent line you might consider something in the 8648 series:http://www.ebay.com/itm/Agilent-8648C-Signal-Generator-100kHz-to-3-2GHz-OPT-1EA-C04-90-DAY-WARRANTY-/291620391405?hash=item43e5ee09ed:g:TlEAAOSwLzdWTkJcThe ad says 100k - 3.2GHz but it's actually 9k - 3.2GHzOr if you like more "analog" controls (more knobs and a meter), you might look at one of these:There seem to be many signal generators in the used market - it looks like a buyer's market.

author: G0HZU
author_rank: Super Contributor
timestamp: December 21, 2015, 08:30:18 pm
content: Cheap and cheerful for 10-520MHz would be a little old Marconi TF2015 but this isn't synthesised and you would need to use a counter with it to get an accurate frequency readout. It also only goes down to 10MHz and the phase noise performance and frequency stability is poor and the max level from it is only 0dBm (1mW)But it is very touchy feely in terms of having lots of rotary controls and this may be useful.The Marconi 2018, 2019, 2022 and the HP8657B don't have any rotary controls so they are not so touchy feely if you need a bit of manual tweaking of the amplitude or frequency.The 2023 is a nice generator but you need to make sure you get one with a working display and one where the buttons are not erratic/deaf in operation. These generators don't tolerate much abuse before the buttons wear out. But they are fairly small and light.The HP 8644 is a big old high performance generator. It weights a LOT and it is very BIG and I don't think it would be suitable unless you have a strong bench and plenty of clear space on it. This generator is not very portable.

author: G0HZU
author_rank: Super Contributor
timestamp: December 21, 2015, 08:32:28 pm
content: QuoteYes, these are nice to use as they have two rotary controls and a simple user interface. They aren't high performance generators in terms of spectral purity etc but they are good workhorses if you can find a cheap one and they are fairly small and light

author: G0HZU
author_rank: Super Contributor
timestamp: December 21, 2015, 08:38:37 pm
content: The other option is the HP/Agilent ESG-A range. The base models of these are becoming quite cheap now and they (usually?) include a basic LF function generator output as a bonus.

author: KJDS
author_rank: Super Contributor
timestamp: December 21, 2015, 09:09:15 pm
content: I've got a pile of HP8657B with the same fault. They are fine up to 1030MHz, but the amplitude goes all peculiar over that. £250 each plus shipping which will be £10