Help Needed to Replace a Power Connector for Tektronix P6045 probe / 454A scope - Page 1
Forum section: electronics / testgear

author: niconiconi
author_rank: Frequent Contributor
timestamp: September 13, 2019, 10:01:26 pm
content: Hi all.I recently found a cheap vintage Tektronix P6045 online, which is a 230 MHz FET probe, the input impedance is roughly 10 MΩ // 4 pF. I think it may be a useful low-capacitance probe for some hobbyist projects, for example, RF at 30 MHz. Do you think it is worth buying? The spec is here:http://w140.com/tekwiki/wiki/P6045Anyway, the biggest problem is the power supply. Tektronix officially designed it to be used with the 454/454A scope that has a power port. Alternatively, with the 015-0073-00 power supply that provides the same power port, it's basically nothing more than two +/- 12.5v linear voltage regulators (built in the late 60s with Zener diodes and discrete transistors, the glorious days), which I think is not worth buying for, and can be easily recreated by two LDOs, or even the crude 78xx.But the power connector is nowhere to be found. Tektronix just call the power connector on the probe a "keyed 3-terminal male snap lock type with grounded shield". I also managed to find a photo of the socket on the power supply as well, i attached the photo, but no additional information.TekWiki is unable to confirm it either, it says "The 015-0073-00 (power supply) has a 3-pin probe power connector (Sealectro 55-850-0018-98?)", note the question mark, and worse, I was unable to find that Sealectro part. I also took a look at the 454/454A scope, which featured the same 3-pin power socket, but again couldn't find additional information.Any suggestion on the candidates for the power connector is appreciated. Thanks!

author: tautech
author_rank: Super Contributor
timestamp: September 13, 2019, 11:47:32 pm
content: Welcome to the forum.I'd seriously consider changing it to one of the locking 3 pin DIN connectors.Google will find a source:https://www.google.com/search?q=3+pin+din+connector&rlz=1C1CHBF_enNZ760NZ760&oq=3&aqs=chrome.0.69i59j69i57j69i59j69i60l2j69i61.2623j0j8&sourceid=chrome&ie=UTF-8

author: niconiconi
author_rank: Frequent Contributor
timestamp: September 14, 2019, 04:28:47 am
content: Well, replacing the power cord on the probe seems to be the only reasonably option left, thanks for the tip!

author: tautech
author_rank: Super Contributor
timestamp: September 14, 2019, 04:31:57 am
content: Quote from: niconiconi on September 14, 2019, 04:28:47 amThere's every likelihood the connector Tek used is commercially available, it's just a 3 pin DIN seems a simple and cheap solution.

author: niconiconi
author_rank: Frequent Contributor
timestamp: September 20, 2019, 03:51:05 am
content: The power cord is clamped on the chassis. In order to replace it, I've removed the wiring, the PCB, the knob, the potentialmeter, everything, but I still cannot remove the front panel to unscrew the clamp and replace the wire, as if the panel is glued or welded in place! How can I remove the front panel and the two screws?The service manual doesn't have instructions for complete removal, so it's probably not encouraged, but the diagram in the service manual shows the front panel is a separate piece of assembly, and the screw should be accessible under the panel.

author: tautech
author_rank: Super Contributor
timestamp: September 20, 2019, 07:34:57 am
content: Looking at your pics closely and my Tek 134 current probe amp they seem of the same style of construction where peering down any cutouts it's evident the front panel is a drop in plate and as there doesn't appear to be any fixing is most probably glued on.I'd be trying to get some purchase on the front plate from behind and through one of the holes after a session with hot air to attempt to soften the glue.Sorry I fresh out of any better ideas other than boiling water to achieve the same thing.

author: niconiconi
author_rank: Frequent Contributor
timestamp: September 21, 2019, 01:56:07 am
content: I turned my hot air gun to 115 °C and evenly heated the entire panel for a minute or two, and used the tip of my tweezers to push the panel outwards at the mounting hole. Bang! The panel comes out.Unfortunately, it also ruined the tip of my tweezers, but I think there's a small price to pay for getting things done.I'll see if I can bend the tip back using a pair of pliers.It wouldn't be possible to get this far without your help. The front panel is fully removed now!

author: tautech
author_rank: Super Contributor
timestamp: September 21, 2019, 05:54:20 am
content: Sorry about the tweezers.