Fisher T 20 battery

[nad]

Dug out an old T 20 from a long time ago..It takes a 12.5 volt battery, and darned if I can remember the number,except I think it was red, and had terminals at each end..The law of averages says it is probably no longer made.Is there some way I can put together a mess of Double A batteries to use the thing again? A bit of a wobble to use, but back in the days when you were making 4300 a year, and could pick off 15 to 30 dollars a week, it was a magic money machine...PS, no clads or pop tops either..I would like to run it up and take it for a walk one more time , thanks NAD

 

[Digger]

I was thinking it was a 9 volt battery. Not the 9 volt transistor type we think of today. But a round 9 volt battery, with terminals on each end. Kind of like those found in some of the early portable radios. But I don't see how it can be 12.5 volts. Since a single cell puts out 1.5 volts, the total voltage of a battery would have to be a multiple of 1.5. That could be 1.5 volts, 3 volts, 4.5 volts, 6 volts, 7.5 volts, 9 volts, 10.5 volts, 12 volts, etc. You may find out it wasn't a 9 volt battery. But I'm pretty sure it can't be a 12.5 volt as you mentioned.

If it were mine, I'd contact Fisher Labs and see if they have any information on the M-Scope T-20. ( I think they also made a T-30. ) If they have archived information, they would be able to confirm the voltage requirement. And, if it is 9 volts, you could try another 9 volt source. In fact, you may have to. If the T-20 took the battery I think it did, they are no longer available. But like I said, if it requires 9-volts, any modern 9-volt source will work. Just observe the proper polarity when making the connections. JMHO HH Randy

 

[BJ in Okla.]

n/t

 

[Fisher Customer Service]

I can tell you now, we don't have anything available for this unit. However, you can check out www.youdoitelectronics.com for a start. If not luck there, go on ahead and give us a call 1-800-685-5050 Monday to Friday 8am to 4:30pm Mountain time. You can also check out www.AllBatteryCenter.com. There is also a company called Battery Express that refer a lot our customers to for older batteries. Unfortunately, I don't have the number on hand and won't till I get into work tomorrow. I'm sure one of our technicians would be able to give you some info as well if you have no luck finding an original.

I wish you the best of luck!

 

[nad]

Thank you all for the help.. First, polarity. Black wire goes to the coil,,,Can I assume negative. Yellow wire goes to switch..Positive. If I remember correctly, there may be a set of drawings up in the garage.Will get a ladder and crawl through the inch or so of dust.....A couple of comments about induction balance detectors..First of all ,Tom O'Hara of Orlando , took a T20 circuit, used a ten turn pot to tune it, and that locator stomped.You could hold the needle on any number you wanted. Iron would always dip before going up.I never dug nails..Gold. silver, nickels, clad, and aluminum really sounded off. Actually, I think gold was extra loud..As a Florida machine, never worked in Ohio below a certain temp,maybe mid forties?? I sent the idea to Fisher, and someone told me they came out with a variable resistor tuned machine. Is this correct? Was it any good? Character named Sheldon Canfield, ex electronic whiz at the old OCF research center designed a low frequency BFO..I played with it and it was deep. He died and I could never find where the kids were, or what happened to the "junk".He came up with a sun burst design made of printed circuit copper foil cut very thin , connected to ground (negative) and placed on the underside of the old IB coil. Supposed to fool the detector into thinking it was on the ground, some loss of depth as a side effect. I never tried it, wondering if anyone else came up with this idea and how did it work? Am a total electronics klutz..Once I get that polarity ironed out, will hook up two battery packs from a trashed 1260 and see if the old timer can sound off..Counting the T20, I've had 7 Fishers since the 60's.You think I would do something normal like spiking Geritol with Vodka.Nope, swimming holes this week, get me a partner and hit some crazy places.This Fall, swinging a scythe to get into an 1830's tavern.area.Just got permission. The other owner said NO, but I outlived him...cordially NAD

 

[Digger]

I hunted a nearby fair ground site, one time, about 22 years ago. And the only time I hunted it I found IH cents and SL silver. The 87 year old man who has owned (and farmed) this ground for the past 21 years just plain won't let anyone on his property. In fact, there use to be an old trail going across this property where people walked down to the river to fish. Folks used it for generations. After this guy bought the property, he built a tall woven wire / barbed wire fence entirely around the 40 acres and posted NO TRESPASSING signs about every 25 feet. I've talked to him nearly every year for the past 21 years, trying to get permission to hunt after fall harvest. Nice enough guy. But he just won't budge! The only chance I have of ever finding those old coins is to outlive him. Not to wish him any bad luck, but your post gives me hope!

HH
Randy

 

[Fisher Customer Service]

I can tell you now, we don't have anything available for this unit. However, you can check out www.youdoitelectronics.com for a start. If not luck there, go on ahead and give us a call 1-800-685-5050 Monday to Friday 8am to 4:30pm Mountain time. You can also check out www.AllBatteryCenter.com. There is also a company called Battery Express that refer a lot our customers to for older batteries. Unfortunately, I don't have the number on hand and won't till I get into work tomorrow. I'm sure one of our technicians would be able to give you some info as well if you have no luck finding an original.

I wish you the best of luck!

If it's worth anything, I got that number to Battery Express: 866-863-4352.

 

[Andrea]

Hello, I recently purchased a fisher M scope T20 serial #67999 at an estate sale for $1.50. It appears to take a 9volt battery but does not work. I read it may take a 12.5 volt battery? I would appreciate any help as I would love to get it up and running. I did get phone numbers for Battery Express and Fisher customer service which I will call this week. Thanks for your help. Andrea

 

[Woodstock]

Try the Vintage Metal Detecting Forum some of the fine members there might help. It may take more voltage than you think. If there a negative on one side and a positive on the other it can be higher than 12 volts. And if you have a battery pack with 8 AA's you should be able to wire it up to see if you get any usable power. Even a voltage adapter could be rigged to test the detector. If I remember right I had old Garretts that ran on 5 nine volt battery's. I know this is not a Garrett but a Fisher but never the less it's an older machine and older machines had different voltage set ups. I'll try to do some reserch and see what I can find out for you. HH, Woodstock

 

[Woodstock]

I just did some research on the web and I found out that the Fisher T-20 two box took this type of battery. < NEDA - 1603 (paper clad) 9 volt > This detector is from 1973 so best of luck to you finding one ! Happy Trails and Hunting, Woodstock