Picked up a HP1741 100MHz Scope today :) - Page 1
Forum section: electronics / testgear

author: TheBay
author_rank: Unknown
timestamp: December 10, 2016, 06:35:27 pm
content: Had a notification on a my local Ham Radio Club What's app group earlier today,100MHz scope, free to a good home.I said, I'll have that without looking at itGot over there and it's a HP1741A, was powered up and everything seemed okay with it, he said it's had very little use.I did offer some money but he would not accept.At home I powered it up and checked a few things, seems to be working okay, the "Storage" function works as well.Gave it a quick wipe over and cleaned the bezel, opened it up and its like new inside! Just have to find a new HP badge for it now.This is going to come in very handy for a SDR Transceiver kit I'm building, dare I say it, it feels nice to use a CRO again after using a DSO.Here are some pictures:

author: radhaz
author_rank: Regular Contributor
timestamp: December 10, 2016, 06:41:40 pm
content: Very nice, and for free!

author: TheBay
author_rank: Unknown
timestamp: December 10, 2016, 06:43:25 pm
content: Quote from: radhaz on December 10, 2016, 06:41:40 pmHe said he was on his way to the rubbish dump with it if no one collected it today!

author: Fungus
author_rank: Super Contributor
timestamp: December 10, 2016, 06:45:11 pm
content: That's not a moon, it's an oscilloscope!It can't be, it's too big!!

author: tautech
author_rank: Super Contributor
timestamp: December 10, 2016, 06:59:45 pm
content: They're generally spotless inside thanks to the non-vented enclosure and not bad to work on either.Once upon a time....yeah sounds like a nursery rhyme..........they were 'the scope' to have.

author: PartialDischarge
author_rank: Super Contributor
timestamp: December 10, 2016, 07:13:56 pm
content: Nice!, I own a 1740a. Love the green glow...It can withstand 500Vpp on the inputs and its also nice to play with the delayed timebase!Attached is a pic of 4 out of my 9 scopes

author: tggzzz
author_rank: Super Contributor
timestamp: December 10, 2016, 07:30:33 pm
content: Quote from: tautech on December 10, 2016, 06:59:45 pm... much nicer than the "equivalent" Tek 465!QuoteThe 465 is marginally more portable, with a smaller screen.The Tek 485 and later have the advantage that if you overload the internal 50ohm termination, a relay switches back to 1Mohm to prevent damage.

author: tggzzz
author_rank: Super Contributor
timestamp: December 10, 2016, 07:34:19 pm
content: Quote from: TheBay on December 10, 2016, 06:43:25 pmSounds like you should pay him another visit, and offer to relieve him of some of his other problems.Wheredid you say he lived in Wales?

author: tautech
author_rank: Super Contributor
timestamp: December 10, 2016, 07:39:29 pm
content: Quote from: tggzzz on December 10, 2016, 07:30:33 pmI couldn't remember the other "scope to have" ......Tek 465, thanks.Yep, I'd seen in threads a 465 can be a bitch to work on.Nice feature in the 485, didn't know that.

author: TheBay
author_rank: Unknown
timestamp: December 11, 2016, 07:09:03 pm
content: Noticed a couple of issues using it today, stripped it down and found a few dry joints.Needed an excuse this weekend to try out the new solder I had just ordered (MG Chemicals 4884-227G - Sn63/Pb37)Have used Multicore 60/40 for years but fancied trying some 63/37, have to say I'm impressed so far!

author: tggzzz
author_rank: Super Contributor
timestamp: December 11, 2016, 07:55:59 pm
content: Quote from: tautech on December 10, 2016, 07:39:29 pmAlso 2445 and 2465; probably others as well.

author: edpalmer42
author_rank: Super Contributor
timestamp: December 11, 2016, 08:53:34 pm
content: I've got a 1744A that I picked up many years ago on ebay. The serial number says that it's from 1983. The only problems I've had are dried up lubrication on the time base switch, a bad connection on an IC socket that I fixed by wiggling the IC, and a failed Tantalum capacitor on the slowest timebase range. You might want to check that.Not too shabby for a 33 year old piece of equipment!

author: Cubdriver
author_rank: Unknown
timestamp: December 12, 2016, 03:06:16 am
content: Wow, that's in beautiful shape - looks brand new inside. I'm happy to hear that you saved it; it would have been a crime for it to go to the landfill. Nice score, and the price was unbeatable!-Pat

author: David Hess
author_rank: Super Contributor
timestamp: December 12, 2016, 08:00:23 am
content: Based on the photographs and videos I have seen, the HP analog storage oscilloscopes of that era seem to have sharper and brighter displays than the Tektronix ones I have used except for the 7834 which is in a different class. Maybe someone who has used both can comment about this.The 465M was the easier to repair alternative to the 465 and 465B series. The 485 suffers from a lot of extra complexity but that is the price for bandwidth.

author: TheBay
author_rank: Unknown
timestamp: December 12, 2016, 08:08:14 am
content: Quote from: edpalmer42 on December 11, 2016, 08:53:34 pmYeah the timebase switch on this was playing up a bit, giving me the impression there was another dry joint. I need to clean it up and re-lube it when I get chance.Cheers for the heads up, will check go through the caps when I get 5 minutes, how do you work out the year from the serial number? I will have a look at the back of mine today.

author: tggzzz
author_rank: Super Contributor
timestamp: December 12, 2016, 09:09:59 am
content: Quote from: TheBay on December 12, 2016, 08:08:14 amThere is a design "suboptimality" in the 1740A. Rotating the timebase switch can cause the outside rim of the black plastic pieces to abrade the PCB track. Fortunately that is not part of the switch and it can be repaired with a short piece of wire - but make sure solder doesn't spread onto the gold contacts.

author: Cubdriver
author_rank: Unknown
timestamp: December 12, 2016, 09:50:56 am
content: Quote from: TheBay on December 12, 2016, 08:08:14 amThe serial number tag should have 3 or 4 digits (yours will have four; three were used only in the sixties) followed by a dash (or in some cases a letter) and then if I remember correctly, 5 more digits. The first 3 or 4 digits tell you the year and approximate production run week (??), and the numbers after the dash or letter are a sequential serial number.The format is YRR-XXXXX for instruments built in the 60s, and YYRR-XXXXX for those made in 1970 and after. Y is year, R is run and X is the serial number. To determine the production year, take the first (3 digit prefix) or first two (4 digit prefix) digits and add them to 1960. I'm not 100% certain, but I recall reading somewhere that the last two digits in the prefix indicate what week that production run of instruments started. They may not have been completed immediately - some may have components with slightly later date codes - but this seems to be in the ballpark based on what I've seen. I believe I have something with a late 1969 date code (>week 45) that has a bunch of early 70s parts in it, so I assume it was a run started in late 1969 that finished in early 1970, and mine was a late run instrument.Based on this, a unit serial numbered 634-12345 would be from a run started in the 34th week of 1966. Something with serial number 2023A14199 (the number on my 8640B) would be from the 23rd week of 1980.Wow, that got long and rambly.Probably more than you wanted to know about HP date codes, but there you have it.-Pat

author: TheBay
author_rank: Unknown
timestamp: December 12, 2016, 12:14:25 pm
content: Quote from: Cubdriver on December 12, 2016, 09:50:56 amThanks Pat,That's very useful information.Mine starts 1930, so guessing that's 1979 Week 30?

author: Cubdriver
author_rank: Unknown
timestamp: December 12, 2016, 04:33:08 pm
content: Quote from: TheBay on December 12, 2016, 12:14:25 pmYou got it! Mid 1979 vintage.-Pat