a decent replacement for HP 8640B - Page 1
Forum section: electronics / testgear

author: wd5jfr
author_rank: Regular Contributor
timestamp: October 18, 2021, 06:53:52 pm
content: Gears are split and it's getting too heavy and takes up too much space.What else is a suitable low cost, $500.00 or less alternative with low phase noise and I know it won't be as good as 8640B, like a Rigol or Siglent or their equivalent. 500MHz is top frequency.The 8640 served me well for over 20 yrs for general ham radio use.ThanksHank wd5jfr

author: rf-messkopf
author_rank: Regular Contributor
timestamp: October 18, 2021, 07:47:08 pm
content: I have a Marconi 2024A that I obtained about 10 years ago. A nice unit that produces a clean signal and by far exceeds its specs. I never had much problems with it. It only failed once. Turned out that a power connector was intermittent. I don't use it too often these days since I have newer generators. The only complaint I have about it is its insane front panel operating concept, but one can get used to that.I think the main recurring problem is the display, although I never had problems with mine. These generators are well built, mostly from standard parts, and full schematics are available.

author: wn1fju
author_rank: Frequent Contributor
timestamp: October 18, 2021, 10:12:57 pm
content: You didn't indicate whether or not you are shopping for a working one (with warranty) or you are willing to take a chance (eBay) on fixing one in unknown condition.If it is the latter, you might be on the lookout for a Marconi 2019 or an HP 8657A/B. Both should be adequate and should be about half the cost.Another one I really like is the Fluke 6080A.Unfortunately, the current eBay test equipment listings have been atrocious lately. Not as much being offered as usual, and some of the asking prices are ridiculous (don't sellers look at the "sold" listings to see what the true market price is?). Perhaps it is partially due to less equipment being excessed due to sluggish companies operating at less than 100% because of Covid. But that is a topic for another forum!

author: wd5jfr
author_rank: Regular Contributor
timestamp: October 18, 2021, 11:24:56 pm
content: I wonder if there's anything from Siglent or Rigol that goes LF to 500MHz that's good enough?The HP 8657 is too big!I have an hp 8657A that I like but it has lots of noise!Hank

author: xmo
author_rank: Regular Contributor
timestamp: October 19, 2021, 02:17:34 pm
content: I wonder if there's anything from Siglent or Rigol that goes LF to 500MHz that's good enough?The HP 8657 is too big!I have an hp 8657A that I like but it has lots of noise----------------------------------------------------The Rigol DSG815 is compact. As far as noise - if you mean fan noise the Rigol would be an improvement.If you mean SSB phase noise - it would be a step down. Making a phase noise improvement over the HP in a synthesized generator will probably be expensive or large & heavy - or both.You'd be better off to fix the 8640A.

author: wd5jfr
author_rank: Regular Contributor
timestamp: October 20, 2021, 06:23:22 pm
content: Anyone know if the Opt 323 PLL is transferrable to commercial HP 8640B?I suspect it's not but I though I'd ask.Can't find spec sheet on the Opt 323 and wonder if anyone knows the phase noise?