Fisher 1280 schematic + Stuart PCB´s

[Unregistered]

8" spider coil

Hi nalag,

When my 1235x switched on, resistance on 2-4 is 41,20 Ohms and 1-3 is 40,85 Ohms. On circuit board 3-5 are shunt, 1-5=1-3=40,85.

[nalag46]

Hi nalag,

When my 1235x switched on, resistance on 2-4 is 41,20 Ohms and 1-3 is 40,85 Ohms. On circuit board 3-5 are shunt, 1-5=1-3=40,85.

.

Thanks,
It does not make sense. Danl before says his resistance on 2-4 is 5.22 ohm. You say 41.20 and mine reads 19 ohm. Which is right? I think that although we are talking about 8" spider coils, the frequency of operation of the 1280X is lowered that all the other Fisher models. The 8" coil fitted to the 1280X, although an open coil, is fisically different to the other 8" coils so it must be that the inductance is different too.
Still, it does not tell me if this coil is faulty or not and I still can get any pick up from it.

[marjo]

Help Repair 1280x

Hi Guys
I was referred to this forum by Hermit (Master Hunter) from another site
So far from what I have read this is and excellent site if you need to know the workings of your machine
Fellows my problem is I was hunting by this Creek at the end of my Property
lost my footing on some slime and my coil cable got tangled on a branch and it almost pull it out of the unit
It stopped working instantly, went home and opened it up to find that my suspensions where true it did pull away from the board
I need a picture to show me how to solder it back in the right sequence
A picture like ( nalag46 ) posted back on 10-21 2006 only I need the part where the coil cable is attached to the board that would work real good I think As you can probably tell I'm not no electronic guru but I would really appreciate the help

Thanks in advance For your help
and I'm going to also thank Hermit for directing me to this forum

P.S. Hermit was at the MD&TH forum called (DetectorX.com)
Not sure if he is looking to be praised but I'm trilled to have found this forum its the only one that as given me hope of fixing my detector
Thanks again
marjo

[ivconic]

interesting


Hi people!
I am a bit curious about that S1VP0104 (VP0104N3...or VP1008L)???
Is it P-Channel enhancement-mode vertical Dmos Fet ??? Or something else?
Anyway, it is clear to me what it should be. Switching power supply(sort of).
But sometimes man can not find some component in the nearest store, so i was
wandering if there is any way to replace damn thing?
When i measured power outputs on my 1266, it showed +6.39v and -3.8v.
O.K. i know what is all about. No need to be symetrical at all. The device is
working perfect with those "numbers".... But since i can not find S1VP0104
and make original power supply, i was thinking somehow to replace all stage
with another one. Any suggestions? Easy way is to copy symetrical from CL3
and use one 9v batt...it should give -/+ 4.5 volts.... But i am curious if is
it gonna work properly or not???:confused:
I wouldnt like to redraw pcb, assemble it and later find out that is not gonna
work....
Also it is not possible at all to find those 27M..blah op-amps here...sheesh!
Any replacement for those?
I would like to make another 1266....I am planing to reassemble original one,
copy pcb on paper,later redraw new one,than assemble original,make it work and
at the end make new pcb and assemble another....

Since winter is coming,i was thinking to do that peacefully,step by step.
Also intend to post draws of original pcb's here...when done...
But i would not like to start all that labour without knowing for sure that
i am gonna finishing it properly.....
1266 is very nice for coinshooting although it can be very usefull for larger
items on greater depths too.
Also, 70 kHz is not so easy to obtain,so i was thinking to use 32kHz instead...

One more thing is bugging me; that transformer 8:800...sheeesh!
Anybody knows number of windings?
I am NOT gonna disassemble original...no way! Heh!

regards

[Fred]

Hi Ivconic,

I also still plan to build a 1280 too from a long time, but still trying to find some parts.
For the transistor you mention, i think i had choosen the 2n7000, easy to find,in Europe anyway.I could fibnd the 27m... ic at Conrad , and also a 77 khz cristal.
Now for the 8-800r transformer, that is what stopped me.I have seen some used in the US or canada , but i lost the adress.
all depends where you live, and if you are willing to order parts...
good luck,
Fred.

[ivconic]

Not suitable!


Beware!

2N7000 is N chanel vmos fet.....what we need is P chanel vmos fet here!

regards

[Geo]

Also, 70 kHz is not so easy to obtain,so i was thinking to use 32kHz instead...

One more thing is bugging me; that transformer 8:800...sheeesh!
Anybody knows number of windings?
I am NOT gonna disassemble original...no way! Heh!

regards

Hiiiiii Ivconic. I agree with 32Khz why not. Maybe to loss depth at air or at litle cm in ground but will be better at large depth.
Now about transformer. There are two ways.
1. try a audio output from an old transistor radio (if you remember before years at the output stage they used two transistors who named Push-Pull ha...ha).
2. Try the circuit of CL3 to do +90 and -90 degrees phase shift.
3.....Regards

[Fred]

You are right Ivconic, thanks.I dont know how i missed that, i remember i had found an equivalent, aparently it is not that one.
Have to search again......
Fred.

[ivconic]

yes.


Yes...regards Fred.

Hi Geo!
I was absent a while. I was arrested few days before.Police catched me at some location protected by state!

They took my home made CL3,some tools and few coins (one of them was silver... )
I have several detectors more here at home so i continued with usuall prospecting.
Nothing gonna stop me....ha,ha,ha...
Since wether is still nice i decided to use it and extend my "season" of prospecting a few days more....

I am very interested about your mods on CL3!
See you on CL3 thread in a few days and than we can talk...
regards

[Geo]

Ok Ivconic. I want to know who is the name of program that you draw the electronic shematics because i want to draw the 2 tone audio and the mod that maybe to do. I work with protel 99SE but it is very heavy and dont make formats compatible with other programs.
Regards

[Geo]

Yes...regards Fred.

Hi Geo!
I was absent a while. I was arrested few days before.Police catched me at some location protected by state!

They took my home made CL3,some tools and few coins (one of them was silver... )
I have several detectors more here at home so i continued with usuall prospecting.
Nothing gonna stop me....ha,ha,ha...
Since wether is still nice i decided to use it and extend my "season" of prospecting a few days more....

I am very interested about your mods on CL3!
See you on CL3 thread in a few days and than we can talk...
regards

Ohhhhh i forgot . Be Careful we need you. I don't like the police. I am sure that they take your CL3 for there own purpose????? Now about CL3 the main problem is the coil (who winds another ), the electronic never mind because now we will make better.