Re: Need 20 Meg Switch for 465B

Dave Peterson


I haven't torn into a 465B in detail yet. But from the listings just posted this does look like a switch type I have disassembled several times now. The first was for a broken plunger just as you've described. The white (or grey) plastic plunger has a very small cross section inside the switch. There are two spring slides that are the switch contacts that live inside this plunger. It gets very narrow and is easily broken.

Rather than desoldering the entirety of the switch you can disassemble your broken switch, the new replacement one, and then swap plungers for a simple solderless fix. It only takes some care, and three hands. Just gently pry the front brass clip from the plunger and set the spring aside. Depending on the details of the switch there may be some toggling mechanisms that need to also be carefully removed and set aside. Some switches require a slider to be held aside while pushing the plunger through the switch body and out the back. At this point you need to be careful and observant about how the contacts are placed inside the plunger and switch body. As it comes out the back they're going to want to fly out and get lost.

Now you should find how the back of the plunger has broken off. Slide the entire plunger out the back of the switch body. Do the same for the new switch. Clean everything up well and reassemble. You shouldn't need to lube anything. Still, I put a tiny amount of silicon grease on the top and bottom of the new plunger. But it's probably not necessary, and may be a long term dirt collector. To each their own. I use a tweezers to hold the contact springs in the new plunger as I slide it into the switch. Once that's in it's a pretty easy job to reassemble the front of the switch. If the brass spring holder clip is a bit stretched from removal it may need an ever so gentle squeeze to close it up a tad.

Also be careful getting the push button shaft off the plunger. They can get stretched out being pried off. Then it'll always pop off the plunger if the switch is a pop-out type.

Hope that helps! Good luck!


On Friday, October 29, 2021, 11:49:55 AM PDT, Robert Simpson via <> wrote:

Looks like I need a new 465B 20 Meg bandwidth limit switch if there is one available. So far, no luck. Neither Sphere nor Qservice have one. It is S1414, part number 260-1486-00.
It has been stuck in the ON position, and after several tests, I just confirmed it's broken.
The front panel external part of the switch moves in and out smoothly, but it stays ON.  I can get it to turn off by poking the back side with a hooked dental probe. This pushed the inner slide forward and turns the switch off.
Does anyone have or know where I can obtain a working switch?


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