Tektronix 1503C , dim back light ?  - Page 1
Forum section: electronics / testgear

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: October 05, 2014, 02:05:42 pm
content: I picked up one of these a while back and have a dim back light , and most all I see on the used market are the same .Anyone have a fix or mod ?I am keeping an eye out for the B model , so to have more portable - battery operated , but have not found a battery or enough info to see if I can do a rebuild ?

author: picburner
author_rank: Frequent Contributor
timestamp: October 06, 2014, 12:10:26 pm
content: I have a Tek 1503B, the brightness of my display is as per photo.https://plus.google.com/photos/110597838768297107853/albums/6067055241305530145?authkey=CJPgpv72sLeGtgEThe battery of my instrument was originally composed by 9 x 1.2V 2000mA/h ni-cd elements 'C'size, now replaced with 3500mA/h ni-mh elements.I had to rebuild the battery holder because it broken by the swelling of old items.If it can help I can send you the pictures of the new battery pack andthe dwg file that I used to redo the shells of the pack using a cnc milling machine.Do you have a newer firmware than mine (v4.73)?

author: David Hess
author_rank: Super Contributor
timestamp: October 06, 2014, 12:40:02 pm
content: It looks like an electroluminescent backlight. The inverter output voltage or frequency could be low and that can be checked but some electroluminescent lamps have poor operating life.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: October 06, 2014, 01:18:27 pm
content: I downloaded the service manual , and there is almost nothing in it about the back light - what is in the " service manual " is what I would expect from a operators manual .No details on spec.s to measure for ?I do not have the B - battery model yet , but would like to get that one , anticipating bad battery and many I see do not have the battery / holder , so trying to make / adapt one is more problematic .Mine did come with the manuals - 1503C & the land cable options & manual .Hope to end up with the printer opt. when I get the battery vers.

author: picburner
author_rank: Frequent Contributor
timestamp: October 06, 2014, 02:18:51 pm
content: The service manual that I posted on ko4bb site a few years ago is probably most complete.See page 271 (10B).http://168.144.151.127/manuals/download.php?file=Tektronix/Tektronix_-_1503C_Metallic_Time_Domain_Reflectometer/TEK%201503C%20Service_EN.pdf

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: October 06, 2014, 02:23:12 pm
content: That's the one I have , and the lack of info on the backlightThanks

author: Lunasix
author_rank: Regular Contributor
timestamp: October 06, 2014, 02:36:00 pm
content: I suppose it's the same system as on Fluke 99. It's an electroluminescent sheet powered by a high voltage converter, and it as a limited and short life time. This is a known problem. You can buy a sheet and cut it at right size, but making electrical contacts is not so easy. This way, you can repair it at low cost. But it will never be as bright as modern displays. It was a major default on my old Fluke 99 and it was impossible to install another backlight system. I repaired it as described.Maybe on the Tektronix...For exemple (with converter, not necessary here) :http://www.ebay.fr/itm/Green-electroluminescent-panel-EL-backlight-sheet-w-inverter-12-volt-10x10-cm-/111477103595?pt=UK_Home_Garden_Wall_Lights&hash=item19f48d9bebAfter repair :

author: David Hess
author_rank: Super Contributor
timestamp: October 06, 2014, 06:16:01 pm
content: Artek Manuals has a service manual for the 1503B/1503C but I have no idea if it contains detailed schematics. You might email them and ask.http://artekmanuals.com/manuals/tektronix-manuals/