8568 Question

[rob.manderson]

Just wondering - is the 85662 display used on the 8568A different to the one used on the 8568B or are they interchangeable.  I ask because I have the chance of obtaining an 8568A (bottom part only) for super cheap but would obviously need to acquire the display (and the cables - not cheap).  Is it worth while trying to get my hands on an 8568 that way or would it be better to get it as a pair?

[KE5FX]

Just wondering - is the 85662 display used on the 8568A different to the one used on the 8568B or are they interchangeable.  I ask because I have the chance of obtaining an 8568A (bottom part only) for super cheap but would obviously need to acquire the display (and the cables - not cheap).  Is it worth while trying to get my hands on an 8568 that way or would it be better to get it as a pair?

It's the same.  However, watch out for displays with options (you don't want any of them).

It will almost certainly be cheaper to buy an entire working 8566 or 8568, rather than trying to put one together a la carte.  But don't turn down a really cheap RF section or display section, as it's nice to have a spare-parts donor.

[rob.manderson]

Thanks.  And that's a good point about a donor.  Much to think about.

[cncjerry]

I would only buy them together, with cables, and working.  The cables are the 'short hairs' of the setup.  I think you can wire them up with standard SMB connectors and cables but it takes a few of them.  Looking inside the cable block I see what looks like male/female SMB fittings. 

I bought mine and it was near perfect for $850 locally and then added the 85685A preselector/preamp and an 8444A tracking generator.  Nice setup, way, way better than my Advantest but limited to less than 1.8G.

If you are in the SF bay area I know a guy that has another setup.  It had some noise that he was working on and probably fixed by now.  PM me if interested.  There are quite a few of them out here as I think the 8566B was designed and/or assembled in Santa Rosa at one time.  Maybe just one aspect of it.  I would love to have an 8566b.

[rob.manderson]

Actually I used to repair them for a living back in 1982/1983 when I worked for HP in Melbourne Australia.  (Since moved to the US and living in Phoenix but I'm a dinky di Aussie  ).
I moved out of instrument repair and into software development (still at HP) just before the B versions and upgrades were made available, hence my uncertainty.

They were indeed made at Santa Rosa (and later at Rohnert Park I believe, just down the road from Santa Rosa).  I had the pleasure of traveling to the US for the first time in early 1982 to attend factory training on the repair and upkeep of the 8566 and 8568.

And now, after 33 years away from electronics and soldering irons etc I'm getting back into it as a hobby.

I currently have an 853A/8558B but it just doesn't compare with the 8568.  Oh, and I just bought an HP 8640B - which  really shows the frequency instability in the 8558.  On the other hand, I'm trying to go slowly and convince my wife that I really really do need a better spectrum analyzer. :-)  So the idea of dropping a few hundred here and waiting a while before spending the next few hundred does have it's appeal.

[cncjerry]

Cool, I wish they were still building them in Rohnert Park as it is about 20 miles up 101 from me.  The 8640b is a great signal source, I have an 8648D synthesized source which has a broader range but I wish it had the spectral purity of some of the other generators they made.  Good luck on your search.

[orin]

You can pick up the cables here, but they ain't cheap:

http://www.glkinst.com/cables/hp_cables.htm#856x

Or you can be patient and wait until they come up on ebay.

I have a spare display unit that I'd sell for $200, but it's in the Seattle area and shipping would be $$$.

Orin.