Fisher 1266 PART 2

[ivconic]

Mikes (from http://www.geotech1.com/forums/showt...d=1#post106084) :

Greetings,Ivconic !
Has decided to write to you about results of work F1266!!!
Now works ÎÊ!
It is desirable!!!!!!! In parallel R425 to put the resistor 100êÎì and the diode (as in F1266) and all will work normally. Instead of resistors R324, R313 – 22 kOm – to put till 27-33 kOm. Now you PCB F1265 at me works excellently! Two payments of yours PCB have made and both work normally and even is excellent!!!
I, regret, but my comments on Fisher 1266 have entailed not good consequences – destruction of my site – http:/mikes.front.ru.
Yours faithfully, Michael (MikeS).

[Mikes]

Hello!
What I write to anybody is uninteresting? I do not see any reaction.
Under the theory it is possible to esteem in US 4,514,692.
Yours faithfully, MikeS.

[Mikes]

Greetings, all!
I wish to answer some questions arisen in this theme.
Results of test of a power unit:
VP0104A it is replaced on KP507A,
2N5087, 2N5088 are replaced on 2N3904, 2N3906, but tried and on KT3102, KT3107,
LM336 (2,5v) it is replaced on TL431.
After food inclusion it has turned out 7,81v and 4,11v.
Fine tuning R507 has exposed exactly 8v, and R509 has exposed exactly 4v.
A food remains to constants (8v/4v) at change of entrance pressure
within 9 – 12v, and the current from the power supply is constant (one payment is included) – 10,5 mA.

[ivconic]

I see....hmmm, must think other way to generate 4.8kHz than..

[Mikes]

Hi, Ivconic!
The reason of all losses of depth – the bad or badly adjusted coil.
Yours PCB 32,768 кГц – 4,096 кГц.
1265 – 77,8 кГц – 4,8 кГц.
1266 – 77,28 кГц – 4,83 кГц
Therefore even original 8 "the coil on 1265 shows bad result.
The coil from CZ5 gets to adjustment, but all the same it not an optimum a little.
Regards,MikeS.

[ivconic]

No,no....i do understand that. It is ok what you are saying.
I am only confused and disapointed with original 1265 coil. See?
It turns that CZ5 coil is working a bit better than original 8" coil???
That's what i said in previous post.
Again; today i took from a friend original 8" coil for 1265 and tested it with my handmade - bad, very bad! Worse than tests with CZ5 coil.
Why? I don't know. All the components are as on schematic...

[Mikes]

Hi, Ivconic!
It is not necessary so gloomy to look at the world!
In 1265 the parallel resonance and the coil from CZ5 obviously is used does not approach for experiments. Probably capacities C102 and C103 mismatch a resonance, and it is probably necessary to add capacity in parallel R201. In general I will use self-made DD the coil on 8 192 kHz.. I think, that the result will be good! This week I will make the gauge about results I will inform.
Regards,MikeS.

[ivconic]

".. Electronics works normally..."

Than...? Must be some busted component at my pcbs? I experimented much...most probably some component busted in between!? Not sure.
I will check that site.
Best Regards Mikes!

[Mikes]

Hi, Ivconic!
All is very simple. I too have decided to collect 1265 (yours PCB).
When checked your payment has seen this error.
Now I do a design and the coil. Electronics works normally.
When I will finish completely a design 1265 I will write about all "reefs" at myself on a site http://mikes.front.ru. Naturally there will be references to yours PCB.

Regards,MikeS.

[ivconic]

Problems! Problems! Problems!

Just few hours ago i took original 1265 coil (8") from my friend to try it with my handmade. Very bad behavior! In Disc mode i got bedlam of cracks and beeps! In Static mode it is calm and working but sensitivity is very low....iron pliers bairly at 10cm in air! And also in Static mode it can not see coloured metals at all! I tried everything! Switched coil pins, switched transformer pins, rechecked everything - no result! Frequency is 4.7xx kHz.
With previous CZ5 28cm coil i got so so behavior, but out of phase....with this one, original...worse behavior much!?
Maybe some ic busted in between? Maybe more mistakes on schematic?
I am giving up of this one! To much wasted time for nothing....

[ivconic]

"...Huge schematic mistake! Mikes i own you!.."

I owe you! Not "own"! My damn English!

[ivconic]

Here are updated pcb files!
Cheers!

[ivconic]

Ok..one more tip;
instead VP0104N3 and simillars i used ordinary IRF9622! Wow! I get perfect 8.0 volts now with it and all the things came to proper places!
Than applied Mikes corrections - even better! My 1265 copy started to work exactly as original. I can't get only proper phase by now, not yet, simply cose i used inproper coil. I dont have proper coil so i used Quicksilver (CZ5&7) 28cm coil just for testing purposes. But comparing to past situation and now, i see huge differences and huge improvements. Audio is extra loud (due proper 8v) and Sensitivity, Disc and other presets are working now nice and linear!
Everything simply came on its places! Simply as that!
Ha! I never payed attention on those 27M9 inputs!
Huge schematic mistake! Mikes i own you!

[ivconic]

Just checked. Mikes is right!
Now it is working by the book!

[ivconic]

Yes!