REALLY BIGG QUESTION

[silversmith]

Here's a really BIG QUESTION..........! from the schematic shown, can any of you engineer types tell me which I.C. is the TONE oscillator for the detector (Compadre)? Not the Loop Oscillator. I'd like to play around changing the freq up a bit. Thanks, Ron.

 

[Bowie]

I cant help ya out there,big dummy here. But, there is a forum that is nothing but technical info on metal detectors. lol, like I said, big dummy here, I cant recall the name of it but hopefully this will jog someones memory and they can let ya know where to go.
Good luck,
John

 

[JOHNMARKHAM]

hummm this could be scaryok forgive me but if you cant read a schematic? I'm wondering how are you gonna use a o scope to change freqs?you might want to be careful with playing around ..by your schematic id say the first one is what your looking for..need to enlarge it better without blurring..but you ll need a key to change info..well you should know what you ll need..good luck...

 

[silversmith]

Wow Johnny Are you an Attorney? The only time I saw advice like that was when I was Sued when my dog bit mailman.

 

[JoeR]

You wouldn`t be trying to make a 100khz detector out of that puppy would you?Sort of like a Compass 77B with ground balenceing.

 

[silversmith]

Wow, some friends of mine had a 77B That thing was a detecting fool No, just wanting to change the tone freq I hear coming outta the speaker. Ya know, if you don't need discriminate, that old 77B would be hard to beat today. Thanks.

 

[bklein]

The Q19 circuit is the main oscillator. You change L2 or C27 for the frequency.
This oscillator is the source for all sample timing so changing it will affect that. Many detectors seem to be designed this way
where the pulse rate also sets the audio frequency. There may be other ways to "hack" the circuit a bit to change the frequency but since you don't read schematics, modifying your unit yourself would likely be out of the question.

 

[silversmith]

Well unfortunately, this schematic was for the earlier version and does not apply to the later version. As far as modifying, hey I own a Weller 550 gun, a Ball peen hammer and a BIG frigging flat bladed screw driver. What more could I need........... All I can do is try, Ehhh? Thanks.

 

[blacktoe]

Hey silversmith,

Will you post pics after modifying it with the tools you have? You do need to get some duct tape and a pair of visegrips to hold it together after modifying.
All in good fun. No offense meant.


blacktoe

 

[JOHNMARKHAM]

omg........

 

[silversmith]

Hey blacktoe, no offense taken. I was just giving old bklein a good ribbing. (kidding him) This was a somewhat old posting. Turned out the schematic was for the early Compadre (wish I had one, it can be modified easily) Mine is a late version using surface technology where almost all non-active components are in the flatpack chips. I'm a professional electronic tech in mobile radio for some time, not an engineer. If the active devices are labeled as to their function I can usually figure whats going on outside of my field. In this case they are not labeled, and I'm a little timid about sticking my big screw driver in. Bklein mis-understood what I was I looking for. I didn't want to change the detector frequency but to change the TONE frequency coming out of the speaker. I've since been informed that moving around the diodes on the lower left device on the schematic would have achieved this, but again different board. So I'm stuck........but I can live with the low frequency tone. Thanks for the comeback, always enjoy a little Kabitsing