A different take on the old fisher receiver power switch

[davam]

So anyway I have 4 fisher receivers and use them all Daly, well 2 of them mostly, and it's well known about the flimsy power switch, so I made
up something a little different for the 2 400's I use the most, one in my office and the other in my shop, I like how they turned out and work well
I know most people like to keep things original, but I like the pull on push off much better, and I can always change back to org using the org central
lap parts. The control I used came off a dynaco fm-3 witch is also made by centrelab used the 500 k wafers from the org control the dynaco control
doesn't have loudness taps, so I had to cut those in the case not too hard as it's thin steel to make the shaft work I had to cut a d shaft off a old control
and solder it onto the dynaco shaft, for this I used a piece of 5/16 refrigeration copper and solder it with silver bearing solder I use for HVAC work
it took a little fiddling to get it all lined up right with the faceplate numbers, the power switch is an off the shelf slide switch but is spot welded
to the bracket can be changed with grinder and some hardware it's a 3a spdt unit and I joined both sections should be pretty robust the cap is
for noise suppression /pop eliminator, only issue is the fisher knob can be hard to pull as it's not made for that, I put a hose washer on it and
alls good until I find a small black or brown rubber band to put on it. Wile reworking the pot, I found some nos 500k centrelab single pots on
the bay that had carbon wipers in them, the carbon part read 62 ohms but doesn't seem to bother the operation of the volume control and a plus
it fixed the bad tracking at the low end. anyhoo that's my project, I hope Avery approves

 

[malden]

looks like a good idea but it's not easy to read your 1000 word sentence

also the photos are all banded together, it would be helpful if you could post them individually so that we can zoom in on them

 

[davam]

Thank you for the heads-up on the pix, Malden' these might work better

​

 

[ivan100000]

Excellent work.

My low-tech solution is to use one of those extension cords with a clicker at the end. I leave the Fisher switch "on" at all times, and I put the input/output end of the cord between the Fisher receiver plug and the outlet; I use the clicker end as the de facto on/off switch.

 

[davam]

Excellent work.

My low-tech solution is to use one of those extension cords with a clicker at the end. I leave the Fisher switch "on" at all times, and I put the input/output end of the cord between the Fisher receiver plug and the outlet; I use the clicker end as the de facto on/off switch.

Yes that is what most fisher owners do as the power switch is a common problem i have a 800c that i do that with also i do like the push off that i did on the 400
and I have an OEM control that I can put it back original if I want in the future so i did it in a way the reverting it back would be easy

 

[RS Steve]

I have learned how to rebuild the original power switches and try to save all the good spare internal parts when I can. Most of the time the issue is one of the wishbone contacts gets the end burned off so it no longer makes connection. I don't know how my construction worker hands can do this delicate work, but I have managed. Installing an inrush limiter will stop the damage and ensure longevity along with installing a jumper from the lead that powers the outlets on the rear to wear the other wire connects to the power transformer. This jumper then gives you both contact points of the switch going to the transformer and taking the load. I like to tell all that remove original power switches for replacement to not throw them away, many times I can harvest the good parts for rebuilding others.

Thread 'Saving Fisher tube equipment power switches'

Sep 1, 2020

We all know too well that a weakness in the Fisher tube equipment over time is the power switches. So I decided a few weeks back to disassemble the bad power switch out of the KX-200 I was working on to get an understanding of what goes bad. I was amazed at the little fragile angled contacts that transfer all that voltage through the unit. As you see in the picture, one end has gotten burned off and making that leg of the switch dead. What this also tells me is that these switches should not be thrown away when replaced, but robbed of any good usable parts inside since they can be used on...

• RS Steve
• Replies: 13
• Forum: Fisher

• 

 

[davam]

Yes I do the jumper on those also, luckily I only had one with a bad power switch from a parts' junker, on that one someone removed the internal
Parts and bypassed it 2 other units had the original controls replaced in the past with a cts brand with an improved power switch

 

[grindfix]

Most of the time, the burned switch contacts will still be good enough to pass a very small current needed to power up the coil of an added power relay.