HP182T

[LunguALexandru43]

Hello, everyone!
I just scored an HP182T mainframe with a HP 8557A spectrum analyser plug-in for under 50$. It mai only have a 350 MHz bandwidth, but it's more than enough for what I plan on doing with it. The only thing is that it has an issue with the horrisontal sweep generator (it doesn't work). Has anyone dealt with this before? http://www.hamradio.no/la3tq/hp182t.jpg
this is the beast, it works just fine on manual sweep but it won't sweep automatically. http://www.qsl.net/yo4hfu/Files/HP8558/hp_182t.pdf This is the repair manual for the mainframe and this http://cp.literature.agilent.com/litweb/pdf/08557-90010.pdf is for the plug-in. I'll be very thankfull for any suggestions.
Cheers,
Alex

[pelule]

This repair report (in German) may help to start with:
http://www.amplifier.cd/Test_Equipment/Hewlett_Packard/HP_other/HP182T_Mainframe_V1_0.pdf
BR
PeLuLe

[LunguALexandru43]

Thanks a lot, mine doesn't have power supply issues, though i'll check everything once again. All voltages measured in speck. Though i did find some signs of heat under a transistor in the vertical board.

[IconicPCB]

As a general tip....


The resistors are carbon composition and may age especially the high resitance values... You may have to check them individually .

[joeqsmith]

Nice score!  I had one of the 141Ts with several plug-ins.  Weighed a lot and took up a fair amount of space but was very reliable.   Good luck with it.

[LunguALexandru43]

Thanks, i've seen it going for way more than what i've paid for it. If i can get it working, it'll be a really nice piece of equipment to own. Does anyone know any scope plug-ins?

[pelule]

I also have a HP182T including the HP 8557A spectrum analyser plug-in.
Got mine "for parts only" at that time $30 and could manage to repair (power supply issue).
So I am able make some reference measurements in case of need.

BR
PeLuLe

[LunguALexandru43]

Hey, thanks. I've measured all the power supply voltages inside, all came out just fine (+-100 volts, +15, -12.6). The thing i didn't get was the 48 and 50 volts at J1-J2 in the vertical drive module. Also, i'm suspecting the transistors in the drive module are toast, i've replaced 2 of them, they had obvious signs of overheating underneath them, but i ran out of transistors so I couldn't replace all of them.

[ddrl46]

I have had similair issues with my HP 8558B and HP 8559A, it turned out to be the switch contacts on the trigger knob that had fallen off and required reattaching to the switch.

Here is a writeup somelone else did on the same issue: http://www.orionsword.net/Electronics/TestEquipment/HP8559A/HP8559A.html

[PaulAm]

That's a great link!

Unfortunately, that's a very common problem with that switch design.  If you're lucky, the contacts are floating around the instrument somewhere.

[rdkrco]

That link does not work anymore. How were the contacts reattached? With miniature screws/bolts? If so, what size/type/length?  Something smaller than 0-80 flat head?

[adilmalik]

I have the same display and problem with the 8558B. Initially i also thought it had a sweep problem, but turned out to be the internal/external button on the display and improper connection of the actual analyser module to the mainframe. Try and play around with the button and see if it comes back to life. Also make sure the module is seated right into the mainframe. 

[hcapela]

Hi,

I have the same problem, I tested all the voltages including the high voltages, as for the switches of the HP8558B they were redone and properly fixed and tested the contacts.
I opened a case in EEV,   https://www.eevblog.com/forum/repair/hp8558b-versus-hp182t-sweep-fail-313183/
I wait for a clue / suggestion

Best Regards
H Capela