Fisher 1236 ground balance

Can a manual ground balance pot be added to the 1236x2? I think this would get it more depth.

There would need to be additional circuitry added to accompany the pot.

Could it be done the same way that some mod the Cibola?

II used to know which one adjusted the ground bal..I think r57 is the thresh..and I think the one in the front behind the disc knob is for the iron preset switch mode....

But to be honest I dont think you will see a whole lot more performance with the added G.B. it will sniff things out of bad dirt fine if you just turn the silencer off...it will shut off for lack of better word's one of the filter's...and with the filter off you will hear the ground noise and when hearing the ground noise the good target's will bleed through...

Give it try in some bad dirt....turn the silencer off and you will start to hear pop's clicks and spit's from just plain mineral if you have enough mineral to cause this...Then if you get a target that sounds faint..but smooth and mixed with lot's of spit's turn the silencer on and see if the target goes away...if the dirt is bad enough a legitimate could target can and will disappear if conditions are severe enough....I actually think they way they have the G.B. set from the factory is dialed in about right with the silencer mode to work properly...If you start changing the g.b. it might throw the other setting's out...

the 1236 is a sophisticated piece of circuitry...it is often overlooked because of the price but there was alot of performance put into the 1236 that was basically a ground up build. not a rehash..... To this day is my favorite Fisher for working iron....

I would not mess with it there is a lot of internal adjustment's that the G.B. could trow out of whack...


They way it runs in allowing disced target's and ground noise to bleed through is a very ...very good approach to retaining depth...alot like the 1266 did but more sedated for working iron...


I have seen the 1236 do some remarkable thing's in iron...and depth is no slouch either...

Stay away from the 10.5 coil it adds a ton of weight and not a lot of extra depth...the 5 inch coil is the must have it get's great depth for size almost as deep as the 8 and really sniffs around in the iron...Use the right tool for the right job....if you want to hunt deep grab a 1270/1266 as a compliment...but they cant compete in the iron like the 1236 and the 1236 cant compete in the depth like a 1270/1266....

I wish they could of made a 1236 and a 1270 in one box ...just have a switch to jump between modes..would of been a real killer...

There's a lot to be said for a machine that has 1 tone and ability to hear partial disced target's..really can sniff around the trash when you get your ear tuned...all hunt by ear with this machine.Some people get the most from them some don't....the noise is the key to success on the 1236...

still my favorite low freq detector.

Again I would not worry about a G.b. pot added..
Keith

I agree with Keith...I did an internal GB on my 1270 for my Alaskan soil...while it did quiet it down some the performance was the same. Not a big deal/difference. I would leave it alone. Is your performance that degraded? Some soil is just hard to penetrate...a sad but true reality.

Yukonbuck

CZ-70, C$, CZ-7, 1270, 1212, GM3, GOLDBUG 2.

Yesterday I took it for a stroll and found 3 clad dimes then called it a day. It was kinda difficult to sniff out the dimes though. Went to the same park today and did some testing. I used a dime I dug the day before and here's the rest. Here's what happened today:
Battery check was fine.
1.) I dug a hole about 6" and covered the dime. Did a few sweeps with no target response. Settings were as follows: Disc: 5, Sensitivity: 8 Silencer: Off. No target response.
I cranked up the sens and lowered the disc and still, no target response.
2.) I uncovered the hole and retrieved the dime. Cleaned the hole out and put the dime back in without covering it with dirt. This time, using the same settings and no silencer, it registered with good response but only in one direction. By that I mean, I turned at a 90 degree and it sputtered like it was struggling to register the dime. It seems it's having difficulty with registering a solid tone. When I turned the silencer on, it didn't register the coin at all in any direction.
I used it in the field for a while today with the silencer off and could here the pops and crackles which I do like but it seemed it had a difficult time locking onto anything even with the sensitivity turned down to 5. Almost like it's falsing a lot. Turning the sensitivity much lower and I'll only find coins 2" deep.
Could be it needs a tune up, coil cable wrapped to tight, sweep speed, not really sure. I'm kinda stumped on why such little depth and why it struggles to lock on to a target with the silencer off. It hit good on the dime @ about 5" or less with no dirt in the hole but when I turned to sweep another direction it would sputter trying to lock on.
What's your guys opinions on this. Anyone know why it wouldn't be getting much depth or what seems it's struggling to lock onto a target?
Apprecite the help.
























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Edited 2 time(s). Last edit at 12/27/2011 12:55AM by DiggerD.

Well it sounds like the silencer is working as it should....

Does the machine airtest a coin like say a quarter with good strong audio out to 10 inches or so?Does it start to sizzle or chatter a bit holding it in the air above sens setting of 9? does the the chatter if it has it... go away once you sweep it across the ground with silencer on?

If it does these thing's the G.B. should be fine....Usually when the g.b. is off or the coil is out of tune the machine will be noisy even with silencer on...Will sound like large weak target's everywhere you scan...


your in ground testing was done with dirt and without dirt but it was also done with silencer on and off if I read correctly?

you stated you cleaned out hole and placed dime in uncovered but then checked with silencer off and heard from N/S sweep but not E/W sweep...

If you did check it with silencer off on covered target please notify...

Now with that said you cleaned hole out very well but there could and possibly is something deeper in the ground below the hole of an iron nature...this is normal behavior for larger iron on the 1236...it will be silent with silencer on but only hit one way when off...


It could very well be you have laid the dime on top of a target a few inches deeper than dug hole....


Also is this the same area you are getting alot of weak hit's on the dime's?and if so it could be just an extremely iron contaminated area....this type of scenario will play out this very way in area's with lot's of debris.....and if it's a new machine to you it will be even more intimidating...


May I ask your experience level in detecting also? Not to be negative in any way but it will help to understand a little better ...

If you are new to detecting thing's can be and sometimes are askew till they are cleared up...


Keith



Edited 1 time(s). Last edit at 12/27/2011 01:11AM by Keith Southern.

Also, what area do you live in...what does your soil look like. The air test question by Kieth is important...Is there electromagnetic interference (EMI)? Put it in all metal mode and scan the area where you're having problems...lots of chatter? That could mean lots of junk or lots of mineralization. Do you get lots of chatter with the disc off and holding the coil in the air? If so it's EMI. If you do an air test, do it away from anything electric. I used the 1236 a couple of months ago and noticed it was very susceptible to interference from underground power cables. Wiggle the connector at the box end while doing your air test and make sure nothing changes dramatically....Could be a bad solder joint. Personally I think you're in some bad soil and maybe having some EMI issues. If it air tests a dime, away from electric sources, at 7" or better at sens 6 and disc 5 then your detector is fine.

Yukonbuck

Keith
Kieth, let me start off with a thanks for your help.
I just air tested with a quarter and the most I can get on the air test is 5" to 5.5" when it starts breaking up. Solid hit at 4". I tried all settings with the same results. The silencer on or off didn't change the depth on the air test. When I used it in the park today, the silencer when used, cut out the iron chatter but I suspect I wasn't getting the depth. When I found the 3 dimes, it was difficult to locate them because they only hit in one direction and sometime the signal disappearing and then coming back all while sweeping in the same direction. Neither dime locked on very solid. With the silencer off, it does continuously beep like there are targets everywhere but nothing seems to lock on. It sounds more unstable or falseing alot. Not sure.

As far as my experience, I'd say off and on around 2 yrs. I used a Cibola with good sucess for some time and made the mistake of selling it a few yrs. ago.
Thanks for the help all. Keep the posts coming.



Edited 1 time(s). Last edit at 12/27/2011 03:42AM by DiggerD.

My 1236 with the silencer on will hit my 7 1/2" clad dime and 8" clad quarter in my test garden. HIts deeper when the ground is damp. Maybe your ground was dry? I run mine max sensitivity and disc 5 1/2.

Rick N. MI

Rick, N. MI Wrote:
-------------------------------------------------------
> My 1236 with the silencer on will hit my 7 1/2"
> clad dime and 8" clad quarter in my test garden.
> HIts deeper when the ground is damp. Maybe your
> ground was dry? I run mine max sensitivity and
> disc 5 1/2.
>
> Rick N. MI
No where close to that in air test on mine with the silencer on and in all metal. I seen 3 pots on the board. Are one of these for sensitivity and can it be adjusted without adjusting the other two.

O 'k" that is way off from what it should get a quarter at if you have gain near max it should get at least 10 inches....

Do you have another coil to try?

I assume the batteries have been changed out?There the first culprit on the 1236 for poor depth..Change batteries even if the battery test is loud....Use good quality alkaline like energizer...

Had a guy send me a Cibola I had modded for him because of poor depth and the batteries were so weak it would hardly beep past 4 inches...I know it sound's strange but it does happen...He was quite embarrassed !It happens to the best of us...

Another thing could be a bad coil or wiring problem at the connector...Check you wires inside the connector...they should have silicone around them at the solder joint's ..some don't they can short against the inside of the connector and cause problem's..

As far as experience goes you have a grasp on what to expect...I was just asking to get on the right page with each other....

Also is this a new machine to you? has this just started?

One other thing what does it do in iron disc lock position does it have more depth?or the same?

We will figure it out !!! just a simple process of elimination..Start with obvious simple solutions first...

Keith

it on the back next to the coil connector if I can remember correctly...the one on the front is the one that sets the iron disc .. it like setting your front disc on 4.25 it just preset.. you can change it anywhere you like on the disc range and the clicker switch on disc control activates it...but they set it to equal a 4.25..

Now if your machine starts to chatter at 9 or so on sens messing with the r56 wont help... if it is quite at full gain it can be turned....

if it is a used machine someone could of monkeyed with the pot's..

The best way to set it is get the front sens knob on about 8.5 or a little below 9 then turn r56 till it start's to sizzle then stop and leave it alone...use a non metallic screw driver...and get in an area away from electrical interference......I take mine way down in the deep wood's and set mine to a barley audible buzz at around 8.5 if you set the internal to high it will start to buzz at about 7 or so and time it get's to 9 or so it's is in overload...so get it to come in at about 8.75 or so thats right on.....

But if you already get the buzzing/sizzling type sound around 9 or so leave it alone.

Keith

Here's what I got Keith,
New Eveready Gold Alk batts.
The wires look okay as far as I can tell. I don't have another coil to test.
On the sensitivity, It starts lightly chattering around 8.
In iron disc lock, It will get about another 1/2" to 1" of depth. The grand total of approx 7" with some crackling. Not a solid beep but crackling along with the beep. The iron disc noise is normal but the depth it seems should be greater. I would think at least 8-9".
It is a used machine. When I got it, there was some dirt on the knobs and faceplate around the pots. It is quite an older model being a los banos and serial 1023. Could be a lot of dust inside the pots. Is there a safe air cleaner to use on the pots and try that?
It sounds like the gain doesn't need adjustment. Could be the coil?
Do you guys hunt with the gain slightly chattering?



Edited 3 time(s). Last edit at 12/27/2011 06:09AM by DiggerD.

If it starts to sizzle at 8 you are good to go!!

the extra little depth you get in iron disc is about right since it drops the disc to 4 so that about normal operation...

seems like the machine is probably right...

I bet the culprit is in the coil....

If I had a coil lying around for a 12xx series I would send it to you for checking out...I just dont have one right now...couple of month's ago I had 2 in a box but I got rid of them....Figure's!!LOL!!!

maybe you can locate a coil and see...Any detector shops in your area they might have one to let you plug in for a second...

if it turn's out it's not the coil a trip to texas is the next step...it would be in the circuitry...


you can spray electronic cleaner on the pot's but I doubt that's the problem,,, usually dirty sticky pot's are crackly sounding through the audio when turned ...You can get it in aerosol cans at home depot...they also have compressed air in a can...I have cleaned 30 year old detectors with the electronic spray it dry's real quick and wont harm plastic's...get the can that is safe for I.C. chips and circuit's...again I doubt that's the problem...If you use it take batteries out turn machine on to discharge any residual voltage and clean with spray ...let dry ...then reinstall batteries...

Seems like the machine is right if it's not the coil..It would be an easy fix at the service shop I would think..

Keith

Thanks Keith. One thing about the dimes I found, they would repeat on 3 or 4 sweeps but then loose signal and then the signal would pick up again. This was all from the same sweep direction. Could have been a combo of the sweep speed and recovery time of the machine. Although my air test shows quick recovery. Just thought I'd mention this.

Do any of you guys hunt with the sensitivity turned up where you can here a slight chatter from the sensitivity setting?

I always ran mine with the chatter/sizzle ...It goes quite while sweeping if you have mineral's...if you dont the chatter will remain...Set it just on th edge of the sizzle for best depth and ability to hear weak zip's....This is the area where you get the most depth out of the machine...the deep target's are no longer a beep but more of faint buzz causing the sizzle/chatter noise to rise and fall ever so slightly.By using the edge of Sizzle on your setting you allow this to happen and it gives maybe 1 sometime's 2 more inches of depth ....

1236 has a real talkitive audio...and can sniff quite deep once you get "in the zone " with it...

I also used the freq shift alot it can really quite down just about any interference you may encounter from E.M.I.

One thing I found after hundreds and hundreds of hours of use on this model was that in thick iron it would out do the best trash machines at the time...that being the Tesoro's in the 10-12 KHz range.With the 120 degree disc...this was 7-10 year's ago...

The newer Cibola/Vaquero/Tejon with they're Higher freq and broader low end disc range will find more than the trusty 1236 if high iron concentration''s is your hunting area's.....Tejon is the best unmasker that Tesoro has at the moment....So if you think about going back to a tesoro .....[I noticed you said getting rid of the Cibola was a big mistake] take a look at the tejon for a step up from the Cibola...More sparky but an awesome Disc circuit in the nail range for un-masking with just a boat load of high gain...

There's also better un-masker's now-a-day's than the 1236 from other manufacturer's but there's certain area's and certain time's an analog mono tone machine can still upset the competition...

A broad range low end disc range combined with patience and unlimited curiosity can do amazing thing's in a nail patch...

Keith

Thanks Keith. Good stuff there man. I imagine the machine could use a good tune up. Really appreciate the help.

Okay Keith,
I'm finding some things and getting pretty descent with the detector. Still have a few issues with the performance of the machine. Most of the clad I find are not very deep and have good repeatable signals in all directions. The deeper ones, 5-6" range, will get a good signal in one direction but once I sweep it 4-5 times it will lose the signal on one side sweeping in the same direction ( like a one way beep target) for 2-3 sweeps but comes right back.
Sometimes a coin may be a one way hit by urning 45 deg., after a good signal. What I explained above, happens in one direction.

When out with the 36x again today. Your right Keith. This detector does take some practice. I experimented with using the disc and silencer to try and sort targets. The more I use this machine, the more I'm liking it. Had a few falses but I'm thinking sens. was set to high.
Being new to the machine, my first post about depth issues may have been beginner error with this particular model. Experimenting with the settings indoors, I was able to hit the quarter at 8.5". My error was the way I was holding the coin and not centering on the coil. It's turning out to be an excellent machine once you start learning to use the disc, silencer and sens.

THAT'S better!

Yes a concentric coil will have the "SWEET SPOT" at depth!!

Sound's like it is catching on...Glad your coil is not bad...

There great machine's...Loves coin's..

hope you find something great this Year..

Keith