PMEL Forum

Lots of the older HP equipment out there (8566, 3577, 3585, etc) is still usable but tubes are becoming dim, unfocused, etc.  I have sent a couple of tubes out to a vendor who rejuvinates them with pretty good success in the past, but I'm interested in doing it in-house with a sencore CR7000.  Should be easy stuff but the sencore literature gives setup information for thousands of tubes, but I don't see any of the HP part numbers. 

Has anyone else had any experience with this?  Any tube data out there somewhere?

If you have some spare bad tubes, try, carefully, taking off the old HP label and see if the original manufacturer is on there, since, as I recall, HP didn't make the CRTs, just used them.

I noticed this when I was replacing an 8566's CRT with the Agilent kit, that the new CRT was not from Agilent, but I forget who (it's been a lot of years since then, and I'm doing fiber now).

Those setups might be in the Sencore manual...also, sometimes HP put the original manufacturer's PN in thier tech manuals.

Hope it helps,

Mike

I don't know that HP made all of them but I know they made at least some.  I have worked with Richardson Electronics to buy replacement tubes for some items and they confirmed for me when I was trying to replace the tube in an 8562A, that it was manufactured by HP and they couldn't help.  The ones I am looking at now (from 3585A's) only have HP stickers without anything underneath.

For what it's worth I had a 3585A that was getting fuzzy a couple years ago.  I was able to straighten it out by removing the covers and blowing several years of accumulated dust out of it.  It goes without saying exercise some caution to protect your eyes & make sure your compressor isn't blowing out watre vapor.

Seems like I recall some Panasonic tubes in 8590 series, if you locate a replacement for your 3577 please post it, mine is getting dim.

Yeah, I'm working with some 3585A tubes right now.  So far I'm one for three.  I made one better and two worse.  Regarding the 3577A, I did have some luck because I had an old 8562A scrapped out with a good tube remaining.  They use the same CRT.  Seems like for some reason the 3577A's were harder on tubes than 8562A's though they use the same CRT.  You can hardly find a 3577A with a decent tube today.

Thanks for the interchange info.

Not to slightly change the subject, but has anyone had experience with the new retrofit kits for the Tek TDS 500/600/700 series scopes (such as TDS784, etc.)?  I've seen ads by a lab that has an LCD retrofit (remove the weak CRT and replace it with a color LCD - probably plus some other extra hardware).

Just wondering if anyone has tried it.  I can give the company name if anyone wants it.

You're probably talking about Norway Labs.  I had a scope done by them and may have another done soon.  I was overall happy with the result - sent it in to them to be done at their facility because the install was free.  If I had any complaint it is that the LCD might have been a little smaller than the CRT so there was a little "frame" or dead area inside the bezel.  I didn't have an original scope with CRT sitting next to it to compare though so it might not be a fair criticism.  I am sure I will use their service again at some point if not within the next few weeks.

We have an application where we specifically need a TDS694C (if anyone knows of a low priced used one, let me know).  It is for some Tektronix TLA series logic analyzers.  There is only one way to cal them using the cal fixture (which we are VERY lucky to have - Tek doesn't sell them any more).  The closed loop software calls for a TDS694C and won't work with any other model.

So we need to find a budget priced one.  I'm thinking maybe there's one with a dim CRT we could get for cheap and have an LCD retrofit done..

You're probably looking at a minimum of about $8k for a TDS694C from a reputable dealer. You might be able to snag one on ebay for closer to $5k - but that's not for everyone.  If you bide your time, you may see one on ebay with a bad display go for closer to $2k.  It all depends on how patient and risk tolerant you are.  Also I would caution you to make sure the scope doesn't need any options to be compatible with the software or fixture.  I would be happy to help if you want to pm me.

I have a HP8566 with a very weak tube, otherwise it is perfect. If anyone has an update to this post or a link to a company that can repair these tubes I would appreciate any help. Thank you.

Sam
W3OHM

http://testequipmentplus.com/ has an LCD kit for replacing the tube. We did an HP/8562E and it worked great. Was very happy with the results.

Quote from: sreaves on 03-18-2012 -- 11:11:29
I have a HP8566 with a very weak tube, otherwise it is perfect. If anyone has an update to this post or a link to a company that can repair these tubes I would appreciate any help. Thank you.

Sam
W3OHM

I know we have a few, both good and bad (some with display issues).

Techmaster located on the west coast is one of the labs that will repalce the CRT with a LCD and they work great. Have not heard any complaints from any customers.

If you want to take a chance you could probably find one at this site: http://www.govliquidation.com/. The bids start at $150 plus any expense to get it to you. I have seen some 8566s recently I believe they were out of OK City.

Quote from: sreaves on 03-18-2012 -- 11:11:29
I have a HP8566 with a very weak tube, otherwise it is perfect. If anyone has an update to this post or a link to a company that can repair these tubes I would appreciate any help. Thank you.

Sam
W3OHM