(DIY) F1A4 Simple Mod information (hope it helps)

I wanted to say thanks to Lazy Trommel for all of your posts in this forum, they have provided me with the information to mod my F1A4

I did the GPX plug change, mounted the PM Coil Scarab, removed the speaker and installed a speaker jack ( using the speaker wires). I just cut and left the other wires there from the standard plug. The speaker I got for a bargain last week at Harvey Norman for $9. It is self powered and VERY loud. Works a treat. I though about making the momentary GB button, but the one that I purchased probably won't go into the grip without some serious effort. I tried a few times to replug ( bridging) the standard coil only to find that when I got it done that all of the wire was crooked and would not fit inside the plug.. A job for tomorrow I think. The only other problem is to fix the coil mount ( the black piece) is broken on one side inside the shaft and the extra weight of the coil makes it hang crooked. I am not sure if they can be removed from the shaft? Finally I raced down to the park for a quick 5 min swing, I am loving the extra coverage of this coil, these seems to enough for a angle at the front to pinpoint a target. The Scarab seems to have a little more depth than the standard coil in the air test, but this was subject to a lot of EMI (out the front of my house). Should get a good run with it tomorrow.

Awesome! nicely done..

Your arm might not thank you tomorrow afternoon with that monster coil haha.

Hi everyone I have also been playing around with my f1A4 , so far I've installed the 5 pin coil plug , head phone jack with audio boost switch ( yellow wire ) and remote GB button which I mounted in the side of handle , I can't beleive how much sharper this machine seams now , anyway I'm off to Mt Crawford for a bit of a test run . Thanks and nice to meet you all .

Yep that's it Thanks lazy trommel

15+

Its been out on 3 sessions of about 4-5 hours swing time so far and its still reading 6.21v.. (down from 6.47v)

I have finally got mine and done the coil socket and ground balance button and I just made an adapter for the audio. Just scored some of Woody's batteries so I can do the battery mod but I am trying to decide if I should go with a SD style 4 pin plug on the side of the battery compartment or just a simple 2 pin plug.

2 pin if you don't want big holes drilled..

4 pin is best put on the back door of the compartment.. (if you dont mind opening up a big hole)

I have been told that the ground balance wiring is wrong on these diagrams. Can anyone tell me any different ? I have been given a new wiring diagram but I am not sure if I should change it or not yet. If anyone on here has done these mods and knows if the ground grab works or does it need to be changed ? Please let me know. Cheers.
Happy Hunting

It goes across the blue and yellow wires. Make sure you use shielded wire with the shielding connected to the yellow wire.

AuMan

Hi Auman
Ive recently purchased a f1a4 myself and am in the process of modding.
just wondering if you have any suggestions for the shielded wire, and should it be single stand or double,
also for anyone that wants to get rid of that heavy lower shaft i have found that a 24mm carbon fiber tube will fit in the upper shaft quite nicely, you just have to swap the the pads in the clamps that hold the arm rest and the lower shaft, i made a fitting to attach the coil from a 20mm 45degree high pressure fitting just heated and flattened one side and drilled a bolt hole, and routed out the other so it would fit on the shaft, when i get time i will have to put up some photos.
kind regards
boyd

Hi bmzgold, you must have made at least 10 posts before ou can place pics on the forum. Cheers

heavymetal said:

I have finally got mine and done the coil socket and ground balance button and I just made an adapter for the audio. Just scored some of Woody's batteries so I can do the battery mod but I am trying to decide if I should go with a SD style 4 pin plug on the side of the battery compartment or just a simple 2 pin plug.

Click to expand...

diagram isn't wrong, just not the best way apparently..

- Peter.

bmzgold said:

Hi Auman
Ive recently purchased a f1a4 myself and am in the process of modding.
just wondering if you have any suggestions for the shielded wire, and should it be single stand or double,
also for anyone that wants to get rid of that heavy lower shaft i have found that a 24mm carbon fiber tube will fit in the upper shaft quite nicely, you just have to swap the the pads in the clamps that hold the arm rest and the lower shaft, i made a fitting to attach the coil from a 20mm 45degree high pressure fitting just heated and flattened one side and drilled a bolt hole, and routed out the other so it would fit on the shaft, when i get time i will have to put up some photos.
kind regards
boyd

Click to expand...

Jaycar have some screened cable,(it is the grey stuff) use the one with 2 centre conductors, that way there are more strands of copper between your switch and plug so it is less likely to break.

The ground balance wiring between the red and blue wires on the switch does work, but it causes the detector to come on if the button is pressed while the detector is off. It is better to go between the blue and yellow.

AuMan

AuMan said:

bmzgold said:

Hi Auman
Ive recently purchased a f1a4 myself and am in the process of modding.
just wondering if you have any suggestions for the shielded wire, and should it be single stand or double,
also for anyone that wants to get rid of that heavy lower shaft i have found that a 24mm carbon fiber tube will fit in the upper shaft quite nicely, you just have to swap the the pads in the clamps that hold the arm rest and the lower shaft, i made a fitting to attach the coil from a 20mm 45degree high pressure fitting just heated and flattened one side and drilled a bolt hole, and routed out the other so it would fit on the shaft, when i get time i will have to put up some photos.
kind regards
boyd

Click to expand...

Jaycar have some screened cable,(it is the grey stuff) use the one with 2 centre conductors, that way there are more strands of copper between your switch and plug so it is less likely to break.

The ground balance wiring between the red and blue wires on the switch does work, but it causes the detector to come on if the button is pressed while the detector is off. It is better to go between the blue and yellow.

AuMan

Click to expand...

I initially tried Yellow+blue, but testing didn't seem to do anything, later realized I'd connected the socket pins incorrectly .. Sorry for not updating the diagram..

.. If in doubt, AuMan!

Also, now i know where you get your cable! woohoo

Hi Jaros
thanks for letting me know that, looks like id better get back out there and find something worth writting about, dont think many people want to know about the kilos of nails ive found around were i live up here in the mountains , but to me it opens up a portal to the past.

Nails are still finds

So I have been toying with the idea of putting a D class amp inside my F1A4 and use a volume control on it. That way there will be only one connection for the speaker instead of running cables to an amp box. I would also be tapping into the F1's power supply and not have to carry a spare 9v battery for the amp. Has anyone tried this at all ? I would really like to know if it can be done otherwise I will put the amp in the battery compartment as I will be using a Li-Ion battery.
Cheers
HH

heavymetal said:

So I have been toying with the idea of putting a D class amp inside my F1A4 and use a volume control on it. That way there will be only one connection for the speaker instead of running cables to an amp box. I would also be tapping into the F1's power supply and not have to carry a spare 9v battery for the amp. Has anyone tried this at all ? I would really like to know if it can be done otherwise I will put the amp in the battery compartment as I will be using a Li-Ion battery.
Cheers
HH

Click to expand...

Many of the class d amp modules found on ebay require 5v power input. I would not recommend running the amp from the 5v power rails in the detector as it will draw a fair amount of extra current compared to what the rest of the circuits use, drop the rail voltage and upset the stability of the machine.
Probably best to power the amp externally. You can run them from a 3.7v li-ion battery, or there are small power modules that boost the 3.7v to 5v. If you power it from the same power source as the detector you will need to use an audio isolation transformer for the audio input to the amp.

AuMan

Can anyone tell me where the timings go exactly please fix s the info I have for the timings has a bank of 6 resistors but I have conflicting information by the look of what I have

Hi all, I am also new to this forum although I have been a member for a while. I too am interested in doing the gain, channel and frequency mod on the f1a4. Is there anyone here that can help me with wiring diagrams and photo's so that I can get this done. I'm pretty good with a soldering iron and multimeter so I reckon I can get it done. Hope someone can help. Thanks in advance