Fisher F2 signals with no coil / false signals

[DaybyDay]

I am new to this. I picked up a used fisher f2 about a year ago. It worked well for a while now it seems to get alot of false signals everywhere I go. I was seeing if it was my coil. I disconnected it to check and it still would go off when it wasn't connected. If I take my hand and tap near the connection where the coil connects in it will signal as fast as I can tap it. Should it signal with no coil? Not being familiar with it I am wondering is this normal. Any advice would be greatly appreciated.

 

Amazon Forum Fav 👍

Family Maps of Hinds County, Mississippi, Deluxe Edition - Grab it through Amazon!

[Charlie P. (NY)]

One thing you NEVER want to do is run a transmitter without an antenna attached. I assume metal detectors may be the same - but hopefully low enough power that you didn't fry anything.

But it does sound like you have an intermittant short somewhere if poking it gives you a signal.

 

[woof!]

I don't know of any metal detectors that will be damaged by running without the searchcoil. Metal detector transmitters aren't like transmitters for wave antennas.

Meanwhile, copied from another thread:

Metal detectors are useless without a searchcoil, therefore operation without a searchcoil is undefined. Many metal detectors are very noisy without a searchcoil, and an individual metal detector may or may not be noisy without a searchcoil depending on EMI conditions, temperature, etc.

The right question is why are you getting "false signals everywhere" with the searchcoil attached. That's a long list of possibilities: electrical interference, loose searchcoil connector, low batteries, drifted circuit calibration, defect developed in circuit, searchcoil or searchcoil cable developed a defect, failure to reduce the sensitivity level when necessary, .....some folks here can probably think of other possibilities.


The quickest way to determine whether the searchcoil is at fault is to install a known good searchcoil. If you've got one.

If you are unable to resolve the problem through the advice of folks here on the forum, the machine will probably have to go back to the factory for repair.