fisher Gemini 2 or tree or TW-5 or TW-6 electronic question hepl! sensitivity sw.

[prospexican]

well i don't know were to star but this is a question for people who knows or have some knowledge in electronics, i own a couple of 2 box detectors fisher brand, but i do many different test and discrimination and the sensitivity sw is too sensitive meaning tha in some kind a test that i do i just badly turn it and it will pass my desire position, then to control this problem i want to add a 10 or 5 turn variable resistor to the sensitivity switch, the only thing i know is that it is or it originally has a 1k Ohm 1 turn resitsor, so my questions is, can i install a 10 or 5 turn variable resistor type switch to my 2 box machine? and if this is possible how many whats or % kind a resistor should i get? im looking now to fisher diagrams and resistors online but i want to make sure what to get. any help will be really appreciated.
he 1k Ohm info i got it from a TW-5 that i open and it has a 3 leg 1 turn and variable resistor.
it also says type J

 

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[airscapes]

Not sure the size and shape of your Pot, but a quick google search for "1k multi turn potentiometer"
Turns up several sites that sell them. No idea what these units you want to modify look like, but assuming they are battery powered. I would think you would not need to worry about the Wattage spec, just fine one that will fit, lower will be less money. %, lower is better (closer tolerance)
Check this site ETI Systems Precision Potentiometers | Mouser
Finding one that fits will be the biggest issue I would think.

Also you may want to remove the existing pot and measure it's minimal resistance and try and match that as well if the minimal (turned down all the way) spec is given.
another site Bourns - Precision Pots Multiturn

 

[prospexican]

Nice! I will try those sources, and yes they are battery powered, if you google fisher TW-6 or Gemini III or 3 you will find the units and the manual with specs, they are powered by 8 AAA batteries in serial making liitle over than 9 volts each, i have a transmitter and a receptor box and the one im trying to modify is the receptor box, the reason is because at certain mode while im detecting the sensitivity switch or 1 k variable resistor response so quick while badly turning it, so i want to add a 3 to 5 variable resistor to try to delay the quick response of it. So thank you so much for your help and if you have any more advise i will really apreciate it.

 

[airscapes]

If this is an old unit it could just be there is a bad spot in the pot and replacing it with a new OEM pot would take care of the problem. This is like a bad volume control on a tv or raid.. Crackles and goes from quiet to real loud.. If the original pot is available might be a simpler fix.
Remove to old one and attache a digital ohm meter and watch the resistance as you turn the pot.. should be smooth if it jumps, in that spot then it is just a bad POT.

 

[prospexican]

If this is an old unit it could just be there is a bad spot in the pot and replacing it with a new OEM pot would take care of the problem. This is like a bad volume control on a tv or raid.. Crackles and goes from quiet to real loud.. If the original pot is available might be a simpler fix.
Remove to old one and attache a digital ohm meter and watch the resistance as you turn the pot.. should be smooth if it jumps, in that spot then it is just a bad POT.

i do appreciate your suggestions and advise air scapes but im not trying to fix the unit what im doing is a modification and i did it im so happy, the reason i need a 5 to 10 turn switch is because i need more delay on the sensitivity response, becasue i do many different test when prospecting, i know how to know when ferrous or non ferrous metal is present, i know how to calculate how deep a target will be, and now i can sense a solid metal even if it is under a very high mineral soil, but in order to get my test more success, i need the sensitivity to response with a mayor delay becausue when i done certain test the switch response is very very sensitive and sometimes i will pass my desired settings,
unfortunately i only could get a 15 turn locally, and that's what i did use for now, but will update it soon, and i did try 1st on my older TW-5 instead of doing experiments with my TW-6 wish is the later model made by fisher, wowwwwwww can't believe it. it did work, also i did install 2 toggle switches so when i omve them up or down they will go to factory settings meaning factory sensitivity switch and also by switching they will go to my new 15 turn sw, and ignore the factory 1 turn sw. yes! thank you so much folks fro all the advise, im so happy.

 

[airscapes]

That is great! Glad I could be of assistance!