Noise-Reduction for Fisher 1266-X (evtl. 1270-X & 1236-X2)

[Funfinder]

Hi,

Good news - my Fisher 1266-X schematic should be still here:

http://www.geotech1.com/forums/showp...&postcount=149

This link seems to be dead:
http://www.geotech1.com/forums/showp...78&postcount=2

The 1265 circuit is here:
http://www.geotech1.com/forums/showthread.php?t=17696


Don't know about the 1280x but I heard the 1270x wasn't
half as good as the 1265 or 1266.

Perhaps the 1265x was better at 18mm 5pence test because
of the smaller coil (8'' vs 10.5''). But some people seem to
recall the 1265x was slightly deeper as the 1266x -
contrary to the above advertising info paper.

btw. does the 1265x has non-motion pinpointing, too?
(if you pull the trigger below the housing, pushing is Disc 2)

here some additional interesting links:
Seems there are no Fisher 1265-X videos on youtube (perhaps
you have the motivation to film some?) but for the 1266-X.

The signals for the coins at 35cm 1ft. are very weak, though.

http://www.youtube.com/watch?v=GSGs-wEUrY4
fisher 1266x - silver coin

http://www.youtube.com/watch?v=_-D1GfuWaMs
Fisher 1266x - american coins - 10.5'' coil

http://www.youtube.com/watch?v=qjMM8KGwZ3s
Fisher 1266x - american coins - 8'' coil

http://www.youtube.com/watch?v=aUqlK8X_dTw
Fisher 1266x - metal detector test in air


And here is a huge amount of info, also some about the 1265.
http://www.treasurenet.com/forums/re...ng-legend.html


btw. after this 5 pence test info I have tested a similar coin -
1 Cent (Euro) 17mm copper, with the 10.5'' (26.5cm) coil
and I could also detect it at 10'' (15cm) but inside the
livingroom with heavy electricity and radiation stuff.

I guess at an electrosmog free location I would reach it at
20cm / 8'' distance - in air. The slightly larger 2 Cent coin
was detectable indoors at ca. 17.5cm / 7 inches.

With this new mod now it is possible to set the noise to an
acceptable level; before there was no way for indoor usage.

They should have created a much more wide spreaded
sensitivity range for this detector in the beginning because
also outside exists enough locations near powerlines or
special houses that makes searching impossible otherwise.

Perhaps I'll find some very silent spot outside to repeat those
small coin-tests. But already it seems that the complete mod
gives around 20% more depth compared with before.

[reidman]

Well thread is older but though I could add a little info. The 1266 has a deep signal boaster the 1265 does not, what this does is make weak signals louder. To tell you the truth I never liked this feature and wish it could be turned off, its hard to tell the really deap signals from shallow ones like I could do with the 1265, makes me dig more shallow signals I would in most cases ignor. I have owned just about every Fisher ever made and never been disapointed.

[kt315]

g

The 1266 has a deep signal boaster the 1265 does not,

always thought this is one circuit diagram both built. can you give a link on what you mean?
regards

[Funfinder]

> its hard to tell the really deap signals from shallow ones like I could do with the 1265, makes me dig more shallow signals I would in most cases ignor.


Thank you for this info.
Usually it doesn't matter if booster or not, it depends on the size of the target and the signals lenght.

Small shallow finds give a loud but very short signal while deep small finds give weaker but still short response.
Huge and deep buried objects create a signal over a larger area with "soft volume borders"
and extremly deep finds give a fainting signal over a medium small area.

The only big problem of those Fishers is the very limited sensitivity range area.
It's kinda from "over medium sens." to "very high sens." - the lower half part of this setting is missing -
that's why I did this mod and now I have the full sensitivity band.

Somebody also could just trim the internal variable resistors but this could became annoying after some time.


Oh, btw. here is an interesting overview of some old school MDs depths incl. the 1265-X and 1266-X.

http://www.iowagold.com/GOLDEQUIPMENT_PAGES/gold_and_detector_how_to_pick_a_detector.htm

The coil size really matters alot. The 1265-X came with the 8'' standard coil that is only deeper
for smaller coins, smaller than this tested US Quarter 24mm diameter there.

Attached the 1265-X schematic, by pure coincidence yesterday I found two old Fisher folders
from the year 2003 & 2008 on my harddisk that contains some files I didn't knew I have them.

[reidman]

Im a Fisher dealer its in some of the orginal information about the difference in the 1265 and 1266, you can find it on the net search 1266 audio boast. Not sure if any of the orginial information is still
around. First 1266 had 2 circuit boards later units only one. Still one of the best detectors ever built.

[Funfinder]

After a short test I saw or better heard that the Fisher 1266-X still gives a weaker audio signal on more distant targets.
And that signal sounds a litte bit pitched - this may have to to that it almost starts to break off or vanishes for a
short time into erratic noise until its gone.

Personally perhaps I also would prefer the non-boost-version because it contains directly more (depth) information,
but to reach more depth boost is better: that way you can find 1-2 inch deeper targets because you can hear
what's going on at the "border to detection zone" much better.

btw. the Blisstool also has this border sensitivity signal amplification.

If someone dislikes to dig deeper targets all to do is lifting the coil a few inches after detection
and checking out if the signal still is audible.

The major problem of the Fisher (and Blisstool, too) is that very weak signals solve into erratic noise
but electrosmog etc. signals, too, and if those are reaching a certain level they will swallow the weak
detection signals completly. In that case alot sensitivity gets lost.

But this boost-circuit creates a higher contrast level for critical find signals that's why it is an improvement.

And if the site is very noise, even by wind or nearby cars and stuff, it's better if the usually analog weaker
signals have been amplified already, otherwise a person could overhear it more easier.

I'm shure now after almost 20 years someone could replace those opamps and transistors with
less noisy ones to get 30% gain in depth and for those who don't like the signal-booster there
should be way to locate this circuit on the 1266-X schematic and remove or bypass it.

It should be located somewhere close before the final audio output stage - see below.

[scs]

1266 with great depth.Work.

[CWrelichunter]

I have dug bullets from the American Civil War at over 20" in wet soil, with the 1266x. I am interested in modifying mine.

[Mod]

Hy all,

I did read all the answers of this very, very interesting topic. Still, I can remark that none of you all have the same electronic card as my 1266X which is as the 1265's that is to say in two different cards.
I will take some photo (not now as I am in a bar ).
Thus, I do have this problem. I will try to change the coil as another French thread in another forum does explain that it comes from it.

Si faux signaux il y a, c'est que vous avez une ancienne tête pleine blanche, qui a pris de l'âge et qui merdoie.
Si vous êtes bricoleur, il faut l'ouvrir en découpant le joint au cutter et en faisant attention de ne pas arracher le fil qui relie la partie basse de la tête à la partie supérieure ; ce fil est dénudé, la tresse bien étalée sur le plastique, et collé avec un morceau de skotch papier. Ce fil évacue l'électricité statique engendrée par le balayage ; c'est lui qui provoque les faux signaux, soit parce qu'il est décollé, soit parce qu'il a, en bougeant, simplement rayé ou maté la couche noire conductrice de la partie basse du disque. Vous suivez ? ;o)
Il faut donc recoller le fil s'il est décollé, et, de toute façon, passer un coup de bombe de peinture noire graphitée (Blindotub, pour écrans de télé) en protégeant la partie sup' du disque.
Laissez sécher et refermez le tout ; pour le joint, faites dissoudre un morceau de protège-disque dans de l'acétone et faites une pâte.

Bon, c'est un peu galère je sais. Le mieux est de vous payer un disque Spider pour série X, beaucoup plus solide (c'est ce que j'ai fait depuis longtemps ! ;o)

It says that it is due to old coils that can be repared (I do not have really understood what he says but changing the coil for a F2 coil that I already own will probably give me an answer). ..
Ok, I'll give more info when I'll have the time.

PS:: Thank you for this very nice topic !!!

[Mod]

Im a Fisher dealer its in some of the orginal information about the difference in the 1265 and 1266, you can find it on the net search 1266 audio boast. Not sure if any of the orginial information is still
around. First 1266 had 2 circuit boards later units only one. Still one of the best detectors ever built.

This now what I was seeking for explanation. So, mine is one of the first made. Still it is as new, not used ! I have not already found where I can the resistor but I have progressed by my side.

So, I have searched funfinder's potentiometer. It does work if you turn it a bit! I'll take a photo later of the one I talk as soon as I get my bloody samsung....
However, I have remarked that once you turn it sometimes it comes back. So, I conclude that the potentiometer is dead. I have bought a new one and will give the results as soon as I have soldered it.
Bye Bye all !

[Mod]

Hy,

just to say that I have changed the potentiometer (104). It works fine. The older one was not stable indeed.
If you do so, sold new one and just turn it slightly till there is no sound. It is working without solderineg the 150K resistor. Still, I am waiting for one by the post office. So, I will not avoid to test funfinder's solution... Thank's to him.

I'll be back soon.

[satdaveuk]

Hi can these mods be also done on the 1265x ?

[Mod]

Hi can these mods be also done on the 1265x ?

Sorry for the time !!! I think that yes because the problem may be due to the same cause... Just try and tell us !

I hope that it 'll function as well as it was for me!