Connecting HP8568B and HP8444A - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: July 27, 2018, 12:59:34 am
content: I have an HP8568B spectrum analyzer coming back from cal lab. While looking around eBay, I found it's companion tracking generator HP8444A but the seller made a statement that specially made connection cable won't be coming with the unit. As far as I can tell, I don't see anything but BNC and N connectors. So I have no idea what he is talking about. Anyone have any idea on this? What kind of special cable do I need?One of the stock photo showed both pieces were connected via hard line with N fitting. Is this it? If so, can I use flexible coax? It's only up to 1.5GHz....

author: Stray Electron
author_rank: Super Contributor
timestamp: July 27, 2018, 03:35:55 am
content: This should helphttp://azurelectronics.com/HP%208444A%20Tracking%20Generator.htm

author: MadTux
author_rank: Frequent Contributor
timestamp: July 27, 2018, 09:01:41 am
content: It's only a BNC cable to get HP8568 LO to 8444A. Option 58 or better 59 (500MHz local oscillator in 8444A) is important though. Otherwise you'll have to build your own 500MHz oscillator to get it working.

author: tkamiya
author_rank: Super Contributor
timestamp: July 27, 2018, 02:55:37 pm
content: THANK YOU, THANK YOU, THANK YOU BOTH!Yes, the reference page helped immensely.and... Thanks for the info on options. Is there a model made especially for 8568B? It seem kind of a kluge to adapt 8444 by adding a local oscillator.

author: Stray Electron
author_rank: Super Contributor
timestamp: July 27, 2018, 05:01:10 pm
content: Quote from: tkamiya on July 27, 2018, 02:55:37 pmI've never looked into using a 8568 but I don't think so. Go on line and look at one of the old HP catalogs and the 8568 & 8444 sales descriptions and see if it list a special option. But IIRC the ONLY thing special about that cable is the weird plug to fit that 5 coaxial connector on the back of the 8568. Today if it were me, I'd add a type N or other connector to the back of the 8568 and reroute the signal through that and then just use a standard type N patch cable. Back in the day, I took apart a video cable from a Sun computer and used one signal cable and contact out of it to make a patch cable. The Sun contact fit the connector on the back of the 8568 (in my case I think I was using a HP 141) but the jury rigged connector just pushed into the HP connector and it didn't have the proper plastic shell. These days it would be difficult to find one of the old Sun video cables.

author: tkamiya
author_rank: Super Contributor
timestamp: July 29, 2018, 11:26:39 pm
content: I actually DO have THAT SUN connector here. Quite a while ago, I picked up a working Enterprise 3500 server and accompanying monitor. I guess I would use BNC or something if I have to modify the unit. Thanks for the idea. I am now waiting for it to come back from NIST tracable calibration.

author: kirill_ka
author_rank: Frequent Contributor
timestamp: July 30, 2018, 06:30:49 am
content: I think the connectors you are looking for can be searched on ebay as "itt cannon dsub coaxial".Today I was surprised to find a cheap version:https://www.ebay.com/itm/DB-male-Pin-D-SUB-DSUB-Signal-Connector-crimp-for-RG174-RG316-Coax-cable-50ohm/182798806990?hash=item2a8fa86fce%3Ag%3AJMQAAOSwHOpZz7Nv&_sacat=0&_nkw=dsub+crimp+signal&_from=R40&rt=nc&LH_TitleDesc=0%7C0DM53740?

author: tkamiya
author_rank: Super Contributor
timestamp: July 30, 2018, 12:04:43 pm
content: Thanks! I just bought 40 of them from the seller.

author: tkamiya
author_rank: Super Contributor
timestamp: July 30, 2018, 12:26:15 pm
content: and look at these!https://www.ebay.com/itm/D-SUB-DB-Pin-Plug-Jack-Signal-Connector-Gold-plate-RG174-RG316-Coaxial-Cable-/171649843131?var=&hash=item6d936e7785