Fisher F-Pulse important finding

[garikfox]

Hello everyone, i just bought a F-Pulse and want to share some important findings.

Alkaline AA (Panasonic Platinum Power)= Sens-3, works perfect.

Lithium AA (Energizer Lithium Ultimate) = Sens-3, noisy on everything even holding in mid air.

Hope this helps someone because i've been reading about people thinking there pointer is broken.

 

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[Professor of Engineering]

I checked some of the unloaded voltage values of the Energizer Lithium on my test bench and all were 1.7 volts. Although a bit high, this shouldn't cause much, if any trouble. Interesting problem, I will have to look into the chemistry of the two battery types when time permits.

 

[Snap on Man]

Don't take this as a slam against Fisher. I have a F5 and a T2 that I just love.I was going to buy a Tech point when it first came out but it looked like there was some start up problems. Now I read this post and it looks like it is temperamental to batteries. I have a Whites TRX that works fine with any battery I put in it. Looks like Fisher still doesn't have it right. Not a slam just a oplnion.

 

[Toecutter]

Voltage and discharge rate, between the 2 types of batteries would be my guess as the lithium's may have a higher discharge rate along with the voltage being higher....

alot of electronics dont recommend lithium's.....

 

[Deep1]

Pulse induction is not voltage regulated like a VLF.
The more voltage put into PI the stronger transmit signal.
I would like to see the results of an air test, using alkaline at sens 3 and lithium at sens 2.
With the extra voltage, you might be getting the same depth with lower setting and lithium.

 

[smokeythecat]

Something I hadn't heard of before. Interesting.

 

[Carl-NC]

The Tek-point/F-pulse transmitter is driven from a step-up regulator, not directly from the battery. So running a higher voltage won't help.

That very step-up regulator has a problem when driven with more than about 3.4V, and causes falsing. So it works fine with alkalines but not lithiums.

 

[Rick K]

Nice to have the Chief Engineer around to answer the question!

 

[McKinney_5900]

The Tek-point/F-pulse transmitter is driven from a step-up regulator, not directly from the battery. So running a higher voltage won't help.

That very step-up regulator has a problem when driven with more than about 3.4V, and causes falsing. So it works fine with alkalines but not lithiums.

Wouldn't a last stage ballast resistor have rectified this?

 

[LawrencetheMDer]

Hello everyone, i just bought a F-Pulse and want to share some important findings.

Alkaline AA (Panasonic Platinum Power)= Sens-3, works perfect.

Lithium AA (Energizer Lithium Ultimate) = Sens-3, noisy on everything even holding in mid air.

Hope this helps someone because i've been reading about people thinking there pointer is broken.

I just sent my second F-Pulse in for repair/replacement and they can keep it as far as I care. [Nothing to do w batteries.] The first died after a month, would not turn-off. The second started doing the same thing, not able to turn-off, but it is an intermittent problem. May work fine for a week than go bonkers and not be able to turn off except, as a last resort, by removing the battery. This is one of the most frustrating things to happen in the field - what do you do with a pointer that won't turn-off in the middle of a hunt? I even sent Fisher a video of the unit failing to turning off. Just heard back from Fisher and they're trying to say the problem is how I'm pressing the button - they're fu**** nuts and just looking for an excuse other than that the F-Pulse pointer is a real LEMON. DO NOT BUY THIS POINTER!!! You will be sorry. Really sorry to hear that you bought one. Please let us know when yours decides not to turn off...I'm betting 2-3 months.

 

[garikfox]

I actually sent mine back because of this odd voltage behavior, I should've done more testing with the lithium and sensitivity levels.

 

[Hawks88]

Interesting. Thanks for that.

 

[chub]

I just sent my second F-Pulse in for repair/replacement and they can keep it as far as I care. [Nothing to do w batteries.] The first died after a month, would not turn-off. The second started doing the same thing, not able to turn-off, but it is an intermittent problem. May work fine for a week than go bonkers and not be able to turn off except, as a last resort, by removing the battery. This is one of the most frustrating things to happen in the field - what do you do with a pointer that won't turn-off in the middle of a hunt? I even sent Fisher a video of the unit failing to turning off. Just heard back from Fisher and they're trying to say the problem is how I'm pressing the button - they're fu**** nuts and just looking for an excuse other than that the F-Pulse pointer is a real LEMON. DO NOT BUY THIS POINTER!!! You will be sorry. Really sorry to hear that you bought one. Please let us know when yours decides not to turn off...I'm betting 2-3 months.

I like Fisher but it sounds a bit like they are taking shortcuts with the product testing. I remember the F22/ 44 being released with flawed push buttons etc.

Chub

 

[garikfox]

If someone else has a F-Pulse that can confirm using energizer lithium ultimate batteries results in extra sensitivity, would be interesting to see if this happens to all of them. I'm assuming all units display this voltage behavior.

 

[ozProspector]

I just sent my second F-Pulse in for repair/replacement and they can keep it as far as I care. [Nothing to do w batteries.] The first died after a month, would not turn-off. The second started doing the same thing, not able to turn-off, but it is an intermittent problem. May work fine for a week than go bonkers and not be able to turn off except, as a last resort, by removing the battery. This is one of the most frustrating things to happen in the field - what do you do with a pointer that won't turn-off in the middle of a hunt? I even sent Fisher a video of the unit failing to turning off. Just heard back from Fisher and they're trying to say the problem is how I'm pressing the button - they're fu**** nuts and just looking for an excuse other than that the F-Pulse pointer is a real LEMON. DO NOT BUY THIS POINTER!!! You will be sorry. Really sorry to hear that you bought one. Please let us know when yours decides not to turn off...I'm betting 2-3 months.

Hi, I know this is a few years old -- but just wondering if you ever had any progress getting this issue fixed? It appears my Tech-Point (F-Pulse) has the same issue... turns on and works no problem, but as soon as I try and push/hold the button to turn off, it just immediately turns back on -- forcing me to have to unscrew the battery cap in order to break contact with battery and power it off. Really annoying! Unfortunately no longer in warranty.

 

[oldkoot]

The Tek-point/F-pulse transmitter is driven from a step-up regulator, not directly from the battery. So running a higher voltage won't help.

That very step-up regulator has a problem when driven with more than about 3.4V, and causes falsing. So it works fine with alkalines but not lithiums.

I also have the F Pulse what is your recommend battery for the F pulse Carl, I have been using Duracell Alkaline batteries in my F Pulse and they seem to work great, my main complaint with the F Pulse is the volume, I can hardly hear the dang thing

Dang did not realize this thread was from 2019 LOL

 

[McKinney_5900]

I also have the F Pulse what is your recommend battery for the F pulse Carl, I have been using Duracell Alkaline batteries in my F Pulse and they seem to work great, my main complaint with the F Pulse is the volume, I can hardly hear the dang thing

Dang did not realize this thread was from 2019 LOL

These Platinum batteries has been solid ever since I looked into a high drain battery. The factory battery was not strong.

 

[MickeyMaguire]

I checked some of the unloaded voltage values of the Energizer Lithium on my test bench and all were 1.7 volts. Although a bit high, this shouldn't cause much, if any trouble. Interesting problem, I will have to look into the chemistry of the two battery types when time permits.

Fisher recommends alkaline batteries "for best results." I have a new one (latest generation). It's working perfectly so far.

 

[Carl-NC]

The lithium battery issue was fixed quite some time ago.

 

[Tank Circuit]

I just sent my second F-Pulse in for repair/replacement and they can keep it as far as I care. [Nothing to do w batteries.] The first died after a month, would not turn-off. The second started doing the same thing, not able to turn-off, but it is an intermittent problem. May work fine for a week than go bonkers and not be able to turn off except, as a last resort, by removing the battery. This is one of the most frustrating things to happen in the field - what do you do with a pointer that won't turn-off in the middle of a hunt? I even sent Fisher a video of the unit failing to turning off. Just heard back from Fisher and they're trying to say the problem is how I'm pressing the button - they're fu**** nuts and just looking for an excuse other than that the F-Pulse pointer is a real LEMON. DO NOT BUY THIS POINTER!!! You will be sorry. Really sorry to hear that you bought one. Please let us know when yours decides not to turn off...I'm betting 2-3 months.

I just fixed my Fisher F-Pulse PI pinpointer with the exact symptom. There is an electrolytic capacitor (100µf@10VDC) that fails.
It's not unlikely that the symptoms would occur intermittently at first.

There is a moon-shaped insert on the end near the battery cap. This insert can be walked out using a sharp tool. You will see two screws under this cap and the entire bottom cover will slide off. You will see a gold spring-loaded pin sticking out that touches the aluminum housing for the battery screw. You will want to clean these to help keep battery connections when the pinpointer is jarred.
There will be two more screws visible and the entire circuit board will slide out revealing the bad capacitor.

You will want to lay a fine coat of silicone glue over the screw heads after you have repaired the circuit.