HP 8590d input jack - Page 1
Forum section: electronics / testgear

author: Dan Moos
author_rank: Frequent Contributor
timestamp: August 20, 2020, 11:57:08 pm
content: I have a HP 8590d spectrum analyzer on the way. I notice in photos of both the specific one I bought, and other similar ones, the input doesn't appear to be BNC. The manual says that when new, it would have shipped with a male type N to female BNC.Basically, my question is, without the adapter, does the thing have the same BBC input as my scopes, and if not, what should I get for proper basic probing? I do have BNC to SMA adapters in virtually every gender combination on the way, and an SMA to alligator clip lead coming too.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: August 21, 2020, 12:31:50 am
content: Hi,Spectrum analyzers typically have 50inputs. There are some spectrum analyzers that are 75input these were used mainly for cable TV, CATV.I think option 001 is the 75option for the 8590D. Normally you don't want option 001.Your oscilloscope will normally have 1Minputs.You cannot use normal oscilloscope probes on a 50SA.You should get, (at least), a 10dB attenuator and a dc block. Most spectrum analyzers can be damaged by very low dc voltages.Regards,Jay_Diddy_B

author: Dan Moos
author_rank: Frequent Contributor
timestamp: August 21, 2020, 01:33:00 am
content: It's the physical jack I'm asking about. I have a dc block, and know about need for attenuation. I'm aware it it's 50 ohm.What kind of physical jack do these things have?

author: Dan Moos
author_rank: Frequent Contributor
timestamp: August 21, 2020, 02:13:03 am
content: Ok, here's my current inventory. (Most of this is still in the mail.)1 HP 8590D analyzer.1 sma dc blockCollection of sma to bnc adapters, all gender combos.2 male type N to female bnc adaptersCollection of sma inline attenuators, enough to get up to 52 db atennuation.Sma to alligator clip lead.Many oscilloscope probes.Sma cablesBnc cablesWith this assortment, should I be in good shape for typical hobbyist needs?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: August 21, 2020, 10:14:49 pm
content: Hi,The spectrum analyzer will have either a BNC or an N connector for the input.You have Male N to BNC female on your list, so you are covered.You may want to have a Male N to SMA female adapter on the list.You may want some SMA pigtails with RG316 or RG174 50coax.All this stuff comes in various gradesJunk -> good quality -> Metrology gradeI have had good luck with second hand good quality mainly acquired at ham radio flea markets.Junk can be useful if you finding yourself having to cut a cable.You may want some T pieces, although these aren't as useful as you would think in RF.Regards,Jay_Diddy_B

author: calin
author_rank: Regular Contributor
timestamp: August 22, 2020, 01:55:11 am
content: I am pretty sure that the HP specan has a N type connector. There are adapters from N to any type BNC, SMA etc.Something like this,https://www.ebay.com/itm/N-Male-to-BNC-Female-Coax-RF-Adapters-Connectors/312664363859(quick fleabay search)Also a DC block is recommended - protects your input from the user(non careful user)

author: Dan Moos
author_rank: Frequent Contributor
timestamp: August 22, 2020, 05:16:30 pm
content: Concerning DC blocks (I did get one btw).I presume they are basically just a high quality coupling capacitor, right? My question is, does this imply that the analyzer input is DC coupled? If so, why it be? If DC is harmful, why would they DC couple the input? I actually had assumed that the 9k lower freq. limit was because of a.c. coupling.