HP182T - Page 1
Forum section: electronics / repair

author: LunguALexandru43
author_rank: Newbie
timestamp: February 03, 2016, 05:40:16 pm
content: 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.jpgthis 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.pdfThis is the repair manual for the mainframe and thishttp://cp.literature.agilent.com/litweb/pdf/08557-90010.pdfis for the plug-in. I'll be very thankfull for any suggestions.Cheers,Alex

author: pelule
author_rank: Frequent Contributor
timestamp: February 03, 2016, 08:44:16 pm
content: This repair report (in German) may help to start with:http://www.amplifier.cd/Test_Equipment/Hewlett_Packard/HP_other/HP182T_Mainframe_V1_0.pdfBRPeLuLe

author: LunguALexandru43
author_rank: Newbie
timestamp: February 03, 2016, 09:23:46 pm
content: 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.

author: IconicPCB
author_rank: Super Contributor
timestamp: February 03, 2016, 09:44:50 pm
content: As a general tip....The resistors are carbon composition and may age especially the high resitance values... You may have to check them individually .

author: joeqsmith
author_rank: Super Contributor
timestamp: February 07, 2016, 12:02:29 am
content: 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.

author: LunguALexandru43
author_rank: Newbie
timestamp: February 07, 2016, 07:55:09 am
content: 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?

author: pelule
author_rank: Frequent Contributor
timestamp: February 07, 2016, 08:12:37 pm
content: 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.BRPeLuLe

author: LunguALexandru43
author_rank: Newbie
timestamp: February 08, 2016, 07:23:21 am
content: 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.

author: ddrl46
author_rank: Regular Contributor
timestamp: February 22, 2016, 10:51:14 am
content: 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

author: PaulAm
author_rank: Frequent Contributor
timestamp: February 22, 2016, 07:05:05 pm
content: 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.

author: rdkrco
author_rank: Newbie
timestamp: April 19, 2017, 07:46:19 am
content: 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?

author: adilmalik
author_rank: Contributor
timestamp: April 19, 2017, 12:17:30 pm
content: 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.

author: hcapela
author_rank: Contributor
timestamp: February 20, 2022, 09:56:37 pm
content: 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 / suggestionBest RegardsH Capela