I need help with idx pro silverdog red pcb!!

[Tibuck19]

This is the Tx oscillation from the transistors, with only a coil and U1 Ne5534, It look very different of that is described on page 76, When all other ic are in the board this wave form can be seen throughout the board, is this a normal oscillation waveform?

[Tibuck19]

Thank you KT, not very helpful but thank you just the nonetheless, Why i am asking is if i prob the top of the board and they tops of the poly caps and the tops two transistors, i get the TX sine wave showing on the oscope with less amplitude then i would if i prob collector, also when i place the prob on the TX wire, not the bare wire but the plastic coating, if i keep probing the top of the board around U8 there are other wave forms showing on the Oscope.

[kt315]

lowestprice chinese tester kit does all. checking transistors too. of any types. https://www.aliexpress.com/item/3283...archweb201603_
simplest opamps and comparators tester https://www.geotech1.com/forums/show...parator-tester

[Tibuck19]

On page 86 fig 9-4 would one of my problems be coming from the BC327 and BC547 two transistor oscillator? even though i replaced both of them perhaps one of the resisters values had increased causing the step ladder effect?
it is also doing the same thing with the 15 inch 6b coil only the steps are more vertical and horizontal

[kt315]

i don't know why you rather point out the obvious and being negative, rather than the enjoyment for taking in and sharing knowledge about something we are all clearly passionate about.
---
MY ENGLISH IS NOT MY NATIVE. it's FIRST. i write as i can write.
so your emotional waves leave out please.
i did release especial opamps' and LM393' LM339' tester for geotechers. you could use it.
it is simplest and gives an instantaneous answer right-now.
yes, people did not wish to buy but that is their right. then i sold all batch at ebay because the ignoring.
i do all for people. sometimes they do not want to understand in what devices they sure need -!
why they do not want to help for yourself in cases similar to your one???

https://www.geotech1.com/forums/album.php?albumid=109

напиши мне что-нибудь по-русски коль твой русский, я уверен, perfect.

[Tibuck19]

NOT. i am trying to tell you that you did whole job in vain. now you destroyed a metalization in pcb's holes somewhere
in result of the desoldering and just added new troubles.

Seeing how it was no longer working right before i " destroyed it lol" you are not entirely wrong the throwholes and traces are rather small and weak on this board, i do have a rather good desoldering station, ( not a hand pump sucker and desoldering wick! as for adding to trouble it is very possible the few repairs on the traces i had to do might influence or induce some side effects,But again i was not working before the invasive destructive investigation as to what and why it went from working perfectly to having a problem. But rest assured the day after the new board arrives i shall be populating that one to see more clearly what is going on with this one.

however indulge me in a thought if you may, is it not a good practise of hands on learning to read and learn from others with more experience and try swapping things around to better understand the effects one component has on another? i don't know why you rather point out the obvious and being negative, rather than the enjoyment for taking in and sharing knowledge about something we are all clearly passionate about. I Don't just want to have this detector working for it to work, i want to understand why and what to do to solve the problem so one day we can all walk away with something learned and or, perhaps even help improve upon the design of the this circuit,

Again i want to point out, most think the 6b coils dont work with this IDX circuit and im saying it has worked for last two years and work really well i might add, I don't know if its the same where your from however, in North America there are a lot of these used coils in the wild, Would it not be better if we could use them and make them useful again and keep the name Whites Electronics a live a little while longer.

[kt315]

NOT. i am trying to tell you that you did whole job in vain. now you destroyed a metalization in pcb's holes somewhere
in result of the desoldering and just added new troubles.

[Tibuck19]

thank you. the sch taken from the forum.
you have to see two parts on the sch. one part is working independently from another.
EITHER pinpointing mode OR disc mode that you choice.
certainly you are seeking in second mode alltime at field.

Indeed i do understand that, so what are you trying to tell me? somehow the two halves are interfering with one another?

[kt315]

I dont have the schematic for this board i believe, the board is the Red one that Silverdog sells, the schematic i am trying to use as a reference is an older one with the VR Trim pots mounted to the board itself.

[ATTACH]54306[/ATTACH]
[ATTACH]54307[/ATTACH]

thank you. the sch taken from the forum.
you have to see two parts on the sch. one part is working independently from another.
EITHER pinpointing mode OR disc mode that you choice.
certainly you are seeking in second mode alltime at field.

[Tibuck19]

This Classic diagram shows everything ...

this one does seem to resemble the board more than the one i posted

[Tibuck19]

Photo descriptions in order
first photo is Don's coil Ground balanced with a ferrite core top form is TX and Bottom is RX both at the same volts per division. TX is probed on Pin6 U8 and RX on Pin6 U1


Second is with the 10 inch F coil Ground balanced with a ferrite core top form is TX and Bottom is RX both at the same volts per division. TX is probed on Pin6 U8 and RX on Pin6 U1


Last photo is with 6B 8 inch coil that use to work perfectly and no longer works right, Ground balanced with a ferrite core top form is TX and Bottom is RX both at the same volts per division. TX is probed on Pin6 U8 and RX on Pin6 U1. Notice the step ladder effect on the RX (Bottom form) and notice how its amplitude is greater than the TX which is the opposite to the two other photos.

[Tibuck19]

what schematic you got with the board? would like to look what-it-is.
pleasure

I dont have the schematic for this board i believe, the board is the Red one that Silverdog sells, the schematic i am trying to use as a reference is an older one with the VR Trim pots mounted to the board itself.

[SWL]

This Classic diagram shows everything ...

[kt315]

for starters unless i'm mistaken which is very possible, the IDX red board does not have an all metal or disc mode, it has a normal beep detection mode and a Point point mode which is an audible threshold hummmm, the only way to get a metal mode as you might think of it, is to turn the Disc pot down to 0, in anycase, i was getting the 42- 45 in beep mode with disc pot halfway just before losing the nickels. hope that what you needed to know.

what schematic you got with the board? would like to look what-it-is.
pleasure

[Tibuck19]

Just to correct myself when i said " step ladder effect on sine wave of RX when i probe pin 7 of the 5534" i meant pin 6 of U1 sorry for the boo boo, re reading Don's PDF on making Concentric coil for the idx, Don does mention that the TX and RX on u1 pin 6 should be out of phase which is not in my case with any of the coils including the coil Don has made.