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

[nuggethunter]

hmm i didnt even notice that sorry guys..
does any1 else know my above question?

 

[AuMan]

Yes, that battery pack will work fine and last about 10 hours in timing 1 or 2 and small setting. More power will be used in either medium or large setting, so the battery will last less time.

You can solder directly to the links that connect the side pcb to the base pcb, this is easier than soldering to the battery tabs.

Regards AuMan

 

[Guest]

Quotes from a couple posts made on another forum regarding F1A4 Mods..

The FI4A is a computer controlled unit and uses a LC circuit to set the frequency of the Transmit/Receive not a crystal.
The crystal on the board is the MCUs clock and what would happen if you change it is the Balance and running of the software would change accordingly, meaning it would be quicker to start up/balance or slower according to crystal frequency.

Overall no benefit would be obtained by doing this. To change the frequency of the detector would mean changing the LC circuit by changing either a capacitor or an Inductor.

Don't bother not worth your time/effort..

To change the transmitter timings find the 2 very small smt resisors near the eeprom and remove, cut the tracks under them to allow access to the address lines of the eeprom, by making these address lines high or low you can change the prom code to get different programs for the tx/ rx timings.

This one would be worth a try, IF i can get some info out of some of the more technically inclined on geotech.. (which is very hard) for an open source modding forum nobody seems all that open

 

[Guest]

So, I had originally installed a 4 pin plug on the back of the F1A4 battery housing and adapted it so it could run of M/L batteries..
It worked fine, however! When working in heavy scrub the cable got caught on crap which is really damn annoying..

So! I whipped out the soldering iron and knocked this up..
Top box, booster.. nothing special, class D amp..

Bottom box, routes power to the machine, and audio back to the battery headphone jack, has a low battery alarm
and will switch to the Internal D batteries if the voltage of the Gel cell drops below 5.4 volts also works in reverse, if I'm running off D cells, and they drop below 4.3v..

Anyway, I get bored i build stuff..

 

[nuggethunter]

how many hours are you getting from this battery?

 

[Guest]

how many hours are you getting from this battery?

From the D cells, about 4-5 hours, from the 12Ah Gel cel, last one i tested fully charged, held on for 3 hunts, so probably 8-10 hours total..

What's the battery life like on the modified machine?

 

[nuggethunter]

im useing 4x10000mah 9v, ive worked out to get around 8+hrs approx per set. i have 2 sets of them.
i find them more than enough at this stage.

 

[Guest]

Nice, Yeah I'm using 8x 2500 mAh AA in AA - D cases.. might try out some Li-on systems.

 

[nuggethunter]

i must read the batterys before i say things,
mine are 10000mah D size. not 9v. my mistake sorry.

 

[Guest]

Got to play with a fully modded machine yesterday, one done by Woody... Sweet machine, not much more sensitive than the stock unit, but the depth is far better..

I just can't seem to justify $1250 on the work lol.

 

[nuggethunter]

it prob isnt the cheapest option and i being a novice really cant say what is best.
the guy i got it from sold me on it, hes service and willingness to help me out with alot of knowledge was very good.
i would highly recommend them and there machine. i just need to get out more and find that first bit of yellow.

 

[Wombat_831]

My f1a4 will be arriving this week hopefully I'll be getting into a few of these

 

[Guest]

Updated coil plug..

The one above on page is reversed (as if you are viewing from the front of the socket)

 

[noncents]

Wanna make your stock F1A4 20% better, and gain 20% battery life???

Remove plug from crappy earpiece, throw crappy earpiece on floor, stomp on it repeatedly (It is S!@#, its the S!@# that S!@# S!@#s...)

Buy this: http://www.jaycar.com.au/productView.asp?ID=PS0194

D (Black) C (Blue) A (Red) B (Yellow'unused')

https://www.prospectingaustralia.com/forum/img/member-images/189/1404117246_less_crap_f1a4.jpg
https://www.prospectingaustralia.com/forum/img/member-images/189/1404116423_phot131o.jpg

Thanks for the idea
I did this to my ear piece, but I've noticed that when I plug my head phones in one side is louder than the other. I did use a stereo jack and maybe that is why? Has anyone else done this mode and had the same problem? Or could it be I've soldered it wrong :8

 

[Guest]

Its all about getting those connections right, i found the best way, was to bridge the 2 hot pins together.. that way you get equal audio on both speakers..

 

[noncents]

Hi LT this is how I joined them . The red and blue wire I soldered to the Red line connector, the two silver to the Black line connector and the copper wire to the Green line connector.

 

[Guest]

Easy fix,

If you're using the existing cable, then you only need to use 3 of the wires..

RED+BLUE are your hot connections, which go to the 2 forward tabs.. (or both to your Red Line) then a wire shorting across Red-black..

Greed is your ground wire, so either the 2 silver wires, or the copper are the ground connection, OR both together... You'll have to test that out..

 

[noncents]

Thanks I'll give that a go.

 

[Wombat_831]

Does anyone know what the plugs are for the ground balance button on a sd/gp/gpx and where to get them from I can't load the pic as it's too big on my phone

 

[Guest]

Wombat, i snipped this off the FB group... this is the pic he speaks of..

Probably a proprietary plug.. but maybe not.