Fisher 1266 PART 2

[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!
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]

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!
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]

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

[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.

[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.

[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).

[ivconic]

Mikes i put that handmade aside long time ago.
I had bad luck with it; most of the components i put on pcb's were scraped from other scraped pcb's. So i didn't knew from where to start with troubleshooting!?
Also there were some mistakes on original schematic.
So i lost enthusiasm about it.
But now with your news i am again gaining some enthusiasm and since it is tough winter i might be start it all over again.
So...
confirm me please if those pcb's are alright now? What corrections should be made?
Also..what opamps you put there instead 27M...? Or if you put originals than what should be closest substitutions?
Can you recheck differences on both versions on schematics and draw accurate and proper version of schematic finally?
...
Right now i do have original 20cm ("spider") coil for 1265/66, so there is much sence to me to make again 1265!
I was also thinking to try to merge those two pcb's and make one smaller and compact.
...
Regrads!

[ivconic]

"...So i didn't knew from where to start with troubleshooting!?.."

I had many issues at those pcb's, not only one!
Most dramatical was strange phase behavior!
I simply could not adjust phase properly.
Right now i also have one original 1265 on service and it is acting the same; can not adjust phase, no way! Everything seems to be alright and still it is working very bad. Seems that geb trimmer has no influence at all when turned. Coil is right, OP27 seems right, all caps arround seems right...???
I don't have much luck with those 1265 lately?
...
Not so good detection and bad phase - that's what i gained at my handmade and also on this original one i have at service...

[Mikes]

Greetings, ivconic!
Good work and correct discrimination F1265 depends on correct adjustment of synchronous detectors. We leave a payment the first (where RX and TX), and the second payment while it is disconnected. Further, we disconnect resistors R220, R222. One channel of an oscillograph is connected to U101/14, and the second channel is connected U202/14 and received:



If the picture it is arranged R205 is impossible.
If the picture is impossible, is added in RX – 33-39 nF and again arranged R205.
If the picture turns out from a negative impulse of the channel of synchronisation we change exits U101/1, U101/14.



Similarly we look the second channel – U101/1 and U202/8.



After that we put to the place of R220, R222. All! The first payment is finished!!!!
Yours faithfully, Michael.

[ivconic]

Thanks much! That's helpfull!
Best Regards!

[Mikes]

Also..what opamps you put there instead 27M...? Or if you put originals than what should be closest substitutions?
Can you recheck differences on both versions on schematics and draw accurate and proper version of schematic finally?
Regrads!

I use TLC27M4. It is possible to use TS274, LMC6484. It is possible to use and simple TL064.
Corrected scheme F1265 I will publish little bit later.

[Funfinder]

http://www.sendspace.com/file/poce13
Fisher 1266-X Schematic 10-5-1993 (Rev. I) 300dpi scan
I hope you can need it!

@ ivconic
Good Luck with your work and keep us informed about your progress - it's really interresting!

Do you or anyone else know how to adjust the GEB pot @ 1266-X or a other little tuning to make it go deeper?

[Merc]

Thank you very much. I'll add that one to my collection.

Merc