TDS754D front BNC connector replacement  - Page 1
Forum section: electronics / repair

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 16, 2014, 03:44:44 pm
content: Anyone have replaced the BNC connector on these model? I have the part number in the service manual but i found no datasheet on these and no one seem to have any in stock with the original part number. i did some research on ebay but i don't find the exact part number...tektronix part number : 131–1315–00 CONN,RCPT,ELEC:BNC,FEMALEMfr code : 24931Mfr part number : 28JR235–1If any one know a replacement for this or have some i will be interested, i need to replace all the front bnc connector.Thanks !!

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: August 16, 2014, 06:23:22 pm
content: I have found something similar ...http://www.ebay.com/itm/Tektronix-131-1315-01-Connector-BNC-Female-Bulkhead-Mount-/390521412055?pt=LH_DefaultDomain_0&hash=item5aece3d9d7I don't know if you have the Peltola style BNC. The seller might be able to give you details. He has helped me in the past.The -01 option could mean anything, but at least it might be worth taking the unit apart and comparing it to the pics.

author: tautech
author_rank: Super Contributor
timestamp: August 16, 2014, 09:23:26 pm
content: I am surprised that you want to replace all the BNC's.Are they making intermittent contact with probes?Are you using Tek or aftermarket probes?I am aware Tek used a propriety taper pin and some other connectors would not make reliable contact. A recent thread OP had trouble finding a 4 mounting pin receptacle for his damaged Tek.Are yours 2 or 4 mounting pins?Have you tried:http://www.sphere.bc.ca/

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 17, 2014, 06:55:09 am
content: All 4 bnc have the mating pin like in the picture the material is very damaged, there's no problem for now and i'm using a new Agilent and lecroy probe.Since i just got it i wanted to change the bnc at the same time when i will backup and socket the nvram, i just want to have them on hand to do it when i'm ready.I'm waiting for Tek support to see if they have a part number i can use for that, i don't know if the last 2 digit matter and if can fit in the scope.Sphere.bc.ca have alot of part but the most are for very old analog scope. I think i will need to explore the front panel to get an idea and check if i can find a replacement.

author: tautech
author_rank: Super Contributor
timestamp: August 17, 2014, 10:03:28 am
content: Stumbled on these:http://www.ebay.com/itm/Lot-for-4-BNC-connrctors-For-Tektronix-TDS-540-520-644-684-744-/251256534856Just in case they might do?

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 17, 2014, 05:21:50 pm
content: Quote from: tautech on August 17, 2014, 10:03:28 amThanks !! i will open the scope this week to see the type of bnc and i want to see if i can fit a usb port with the Floppy port too in the process.

author: nctnico
author_rank: Super Contributor
timestamp: August 17, 2014, 06:59:54 pm
content: What kind of floppy/usb drive do you intend to use? I tried one a couple of years ago but I reverted back to using disks. I bought a pack of brand new high quality 3M HD disks. BTW the connectors shown in the Ebay auction are for the rear panel. I think you need the ones which go straight into the attenuators. You might be better off by replacing the entire attenuator assembly.

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 17, 2014, 08:37:49 pm
content: Quote from: nctnico on August 17, 2014, 06:59:54 pmI did some research and i think it will be easier to buy a floppy to usb and use floppy disk instead, like you did or if i can find a software to get the data on the gpib. The picture of any tds 500/600/700 att assy show the bnc in the casing, maybe this will be easier to replace the assembly but since i'm in i will see if i can find something similar.

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 18, 2014, 10:15:53 pm
content: Update from tektronix about the connector,The 131131500 has been replaced by the 131131501, which is still available for purchase. Current price is $12 each (min order of 30$) if you buy from tek.i found these on ebay,http://www.ebay.ca/itm/380812143958?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l26494 new shinny bnc connector under 30$ us with the shipping !!i will update the thread when i open the scope and install these.

author: nctnico
author_rank: Super Contributor
timestamp: August 19, 2014, 07:53:37 am
content: I'm pretty sure you ordered the wrong BNC connectors. Look at this Ebay auction for an attenuator casing:http://www.ebay.com/itm/Housing-with-BNC-for-Attenuator-Hybrid-for-TDS-784A-TDS-744A-TDS-794D-TDS-784C-/251298056465

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 19, 2014, 12:01:11 pm
content: Quote from: nctnico on August 19, 2014, 07:53:37 amYeah i saw this auction too, it seem there a tab connecting the bnc with the pcb, with the set screw under there's 2 choice, 1 the bnc and the pcb tab is 2 separate thing and you screw the bnc in the hole with the pcb tab adapter at the end, the service manual show a nut and a washer so i think it's that and there no space to rotate the tab in the picture, or it's 1 connector with no thread and you slide in in place and secure it with the screw...And a quick look at the service manual this morning show me that the new part number they gave me is the same as the rear bnc connector so a teardown tonight is scheduled , I wrote to tek to be sure, and well if it's not the right one i will just sell them back or keep them forever

author: nctnico
author_rank: Super Contributor
timestamp: August 19, 2014, 07:02:05 pm
content: The 'TDS520B component service manual' shows the same part number for the rear and front BNC connectors. I'm wondering what you will find in your scope.

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 19, 2014, 08:53:52 pm
content: Update from tekI do not have much documentation on the component parts for the TDS754D. The TDS754D out of Tektronix long term support in 2007. (It was serviced at the module level - not component.) From what I have been able to find, the attenuator BNC's were 131536100. (See attached document). Unfortunately, this part is no longer available.they gave me this data sheet and some research on google show that was for the TDS500/600 so i will know when i open it, i found some similar on digikey but i need to remove 1 to take the exact measurement.

author: AwArD_RzD
author_rank: Regular Contributor
timestamp: August 20, 2014, 12:21:11 am
content: well i removed the attenuator assembly and the channel 4 hybrid, i had to stop because all the set screw are stuck in the casing, i don't know if there some lock-tight or it's just too much torque, but i have quality tool here and i twisted one allen key and i don't want to risk to put stress on the other soldered hybrid.I have all the tool where i work to remove the set screw and keeping the thread inside but for now i will keep them like that, if one fail that will worth the time to do this.At first glance the outer flange ring is very small and the 12 mm bnc will not fit inside, the 131536100 is 10 mm. For the length i can pry the metal flange so 1-2 mm more or less is not an issue. The thread seem standard. i found some 131536100 image and it look like the one in the casing. Well i think this put and end on this project for now.There some photo of the acquisition board and the attenuator assy.

author: siggi
author_rank: Regular Contributor
timestamp: August 28, 2014, 12:07:12 am
content: I'm just going through the same thing with my TDS784D, where the channel 3 BNC connector is marginal. I have a "spare", a probably-dead TDS684A, which has the same attenuator assembly.Quote from: AwArD_RzD on August 20, 2014, 12:21:11 amI got the set screw out - it was very hard to get moving, but once it snapped it was fine. Someone on the TekScopes forum suggested that heating the set screw with e.g. a soldering iron will soften the locktite.I removed a BNC connector from my spare assembly to see what they look like. It was a bear to get out, and I totally wrecked the connector in the process. Heat might have been a good idea, but the attenuator assembly is fine. After cleaning out the residual locktite off connector and assembly with IPA, the threads feel just fine.Now, the measurements in the data sheet you uploaded are all bang-on to the connector I pulled.It looks like a pretty regular BNC, except it's long - 14.5mm from the back of the flange to the front of the connector. More usual is to see ~12mm; this from staring at mechanical drawings on e.g. DigiKey. The flange is also smaller than typical, it's 10.8mm instead of the more usual 12-12.5mm.I found that QService had a couple of suitable BNCs on stock, but after ordering them I noticed that those are used - so I don't know what sort of state they'll be in.Note that there's a code stamped on the front of the connector, which on mine reads 28JR472–1. This matches the part number in the TDS520B service manual, and this part number turns up a few suppliers (hoarders?) on the interwebs who claim to have them in stock.See e.g. <http://www.1sourcecomponents.com/availability/Berg--28JR472-1.htm>, who claim to have 2198 in stock.Has anone here done business with this ilk of supplier?Alternatively I noticed that the TDS520B SM has a few mentions of the same part number. I suspect the connectors on the back of the scope are the same kind, and maybe it's viable to swap those to the front. I figure it must be easier to replace the back ones with easier-to-find parts.Siggi

author: siggi
author_rank: Regular Contributor
timestamp: August 28, 2014, 05:00:19 pm
content: Quote from: siggi on August 28, 2014, 12:07:12 amI sent them an RFQ for giggles - we'll see whether they have the time of day for me (and at what price).QuoteActually I can see the back panel connectors are different by the pictures you posted. Looks like a panel-mounted adaptor from BNC to some kind coax connection. Scrap that...

author: siggi
author_rank: Regular Contributor
timestamp: August 29, 2014, 06:16:58 pm
content: Quote from: siggi on August 28, 2014, 05:00:19 pmSohttp://questcomp.com/quote me a price of $40 for 8 connectors, $5 each is not bad.Now I've just got to figure out how now to pay an arm and a leg for shipping to Canada, plus brokerage fees, etc.

author: jlmoon
author_rank: Unknown
timestamp: August 29, 2014, 08:15:56 pm
content: "Someone on the TekScopes forum suggested that heating the set screw with e.g. a soldering iron will soften the locktite."Gentle heat works like a champ when removing stubborn set screws, keeps the strip-page count low.

author: siggi
author_rank: Regular Contributor
timestamp: September 13, 2014, 04:30:22 pm
content: Turns out this <http://www.questcomp.com/QuestDetails.aspx?pn=28JR472-1> Is the right part. Quest have 2200 or so in stock.Sent from my iPad using Tapatalk