Silver Sabre

[Sean_Goddard]

Next Time I get a Silver Sabre in for this mod, I'll show you via photo's EXACLTY what needs to be done.

[Qiaozhi]

The guys in Europe are ahead of us as usual. OK, you could identify a component as 8.2K. However, it is too easy to lose the decimal point. The Europeans got clever!!! 8.2K became 8K2. There is absolutley no way that you can lose the decimal point when you label the components in this way. 1.2M becomes 1M2 and 6.8K becomes 6K8. You have to admit tht this is a vastly superior method of writing part values on a schematic. The 24 hour clock is also a vastly superior way to indicate time. It is however completely lost on most Americans!!! We are indeed an ignorant lot!!!

In actual fact the method of using 8K2 for a resistor and 4u7 for a capacitor (for example) is not a published standard for use in schematics anywhere in the world. This is known as the Component Marking Standard. The reason for its use is that the decimal point can get "lost" on the physical component. For most resistors this is not a problem, as a well known colour coding scheme is used, but capacitors are often marked this way. However, the Component Marking Standard has become popular for use within schematics for the same reason, and many companies promote this as an internal standard, even if officially it isn't one.

[steve chappell]

Silver Sabre Mods help pls pls

Next Time I get a Silver Sabre in for this mod, I'll show you via photo's EXACLTY what needs to be done.

Thanks Sean, however, i have a problem locating the diode for yr mod 2 for extra depth running the detector off the battery supply directly, would GREATLY APPRECIATE it if you could amend the schematic and point out where this diode is please, or where it should be if my detector is an early model without such diode.

[Unregistered]

unsure of mod

Thanks Sean, however, i have a problem locating the diode for yr mod 2 for extra depth running the detector off the battery supply directly, would GREATLY APPRECIATE it if you could amend the schematic and point out where this diode is please, or where it should be if my detector is an early model without such diode.

i WANT TO FIT THE MOD POSTED 10/17/2004 SEAN GODDARD BUT I AM
NOT SHURE ON THE CONNECTION POINT FOR THE CATHODE OF THE DIODE AS QUOTED IN TEXT
IS IT THE DIODE WITH THE 510K RES IN PARALLEL .I THINK THE CIRCUIT DIA IS WRONG AS THE LEFT HAND SIDE OF THE IN 4148 AND THE 510K AT TOP OF DIA IS SAID TO BE + BUT ON A SSP CIRCUIT THIS POINT IS CONNECTED TO PIN 5 OF ICL7660 WHICH IS -5V ANY CHANCE OF AN ANSWER BEFORE AUG AS I WOULD LIKE TO TRY OUT THE RESULTS WHILST ON HOLIDAY
CHEERS

[Sean_Goddard]

Post me a photo of the PCB on here and I'll arror up the Diode in question for you (top AND bottom of PCB please).

I dont have a SS to look at so this is why I ask.

[stanley]

Re ssp mod

Hi Sean

Thanks for the quick response, here are the pics you wanted.

Cheers

Stan

[Qiaozhi]

Hi Stanley,

Hope you don't mind. I've resized your photos to the correct aspect ratio.

[stanley]

photo changes

That looks more like it
cheers
stan

[Sean_Goddard]

Haven't had chance to do this yet due to floods in the UK affecting other work I do. Will get round to it as soon as I can. Give me a few days more.

Third close up is wrong area entirely for this mod BTW. Off hand I think it is the red wire near the Transmit transistor.

I'll be REAL quick about this as I have to go to a meeting.

Locate the TX transistor, simply look for the correct values connected around it. Follow the RED and Yellow wires frm the SH connector. Then look at the emitter, you can find the pinout be Googling the transistor type AND TO-92. From this there is a RED WIRE, cut this and solder a NEW length FROM the transistor end pad to the point where the battery POSITIVE enters the PCB (This is AFTER the On/ OFF switch). BINGO more Tx power, but ONLY on new betteries.

If you use Rechargeables you will get moe power and depth for longer. I have ot say though, that on SOME machines this mod WILL make the machine chatter uncontrolably. Best done WITH the sensitivity mod too, this will make a SS as good as the Vaquero without the stupid extra cost.

Hope this helps.

[ivconic]

?

Sean: "...i have ot say though, that on SOME machines this mod WILL make the machine chatter uncontrolably..."

Yes Sean, i gained extra 2-3cm depth but also instabillity when Sens. is on Max... Also chatterin silently all the time..?
Is it because of a coil or something else?
Dont have simillar problems with G.Sabre and same coil...
regards!

[stanley]

Haven't had chance to do this yet due to floods in the UK affecting other work I do. Will get round to it as soon as I can. Give me a few days more.

Third close up is wrong area entirely for this mod BTW. Off hand I think it is the red wire near the Transmit transistor.

I'll be REAL quick about this as I have to go to a meeting.

Locate the TX transistor, simply look for the correct values connected around it. Follow the RED and Yellow wires frm the SH connector. Then look at the emitter, you can find the pinout be Googling the transistor type AND TO-92. From this there is a RED WIRE, cut this and solder a NEW length FROM the transistor end pad to the point where the battery POSITIVE enters the PCB (This is AFTER the On/ OFF switch). BINGO more Tx power, but ONLY on new betteries.

If you use Rechargeables you will get moe power and depth for longer. I have ot say though, that on SOME machines this mod WILL make the machine chatter uncontrolably. Best done WITH the sensitivity mod too, this will make a SS as good as the Vaquero without the stupid extra cost.

Hope this helps.

HI sean
you seem to have a lot on your plate at the moment
the reason i put photo number 3 ( shot of diodes)is that in your text for mod part 1 it says for the sensitivity mod replace the 1k with 8k2 with other end connected not to ground but to the cathode of the diode nearby (-5vo).
this is why i included photo number 3 .There ary only 4 diodes on the board and all are in shot .Any chance you can mark up photo with the correct point (ONLY WHEN YOU TIME DONT YOURSELF A HEADACHE OVER IT)
THANKS
STAN

[Sean_Goddard]

Ivconic, I presume it's the 8.2K to -ve voltage mod you are talking about, in which case the chatter occurs for one of the following reason;

You are taking the REFERENCE voltage on the LM393's below the noise threshold of the machine. The SS does not have a sensitivity control as such, just a variable reference. If you have an oscilloscope, look at the inputs to the LM393's they are constantly changing "noise". Now look at the output of the two TIS75's they are the synchronously demodulated Rx signal, BUT they have huge glitches on the tops and bottom cycles. These glitches are switching noise, and JITTER from the two LM393 used to derive the DISC and GEB (could try a 1nF cap to ground on each of these, might help).

IF you trigger your scope off the Tx waveform and then look VERY closely at the output from this 393, the front edge of the waveform will appear to move back and forth. This is jitter and it is the cause of the noise in the SS. If this jitter can be got rid of, the SS can be run a LOT "hotter" with depth and sensitivity matching todays Tesoros.

If you wanted to , you could replace the 393 with a better "zero crossing detector" or even a phase locked loop and get MUCH cleaner switching singals. Then you would need to clean up the switching noise, but not too much or you simply lose the extra depth you gain.

You could try fiddling around with the "filters" if you REALLY wanted to go to town, my first choice would be to INCREASE the 0.1 capacitors to .22 or .47 (uF I think) this would mean you would have to sweep more slowly as the filter response is now of a lower frequency (or is it sweep faster, I can never remember). Anyway, you could try that and see where you get.

Oh, I nearly forgot. If you REALLY want to tweak this mod, put a 20k trimmer instead of the 8.2K resistor, then you can "tune" the mod for optimum.

[ivconic]

Well done!

Thanks a lot! I will check those asap...Inform you later