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1N5229 diode
Hello Duncan - I know you addressed Merc -
The 1N5229 diode is a 4.3V zener, 1/4 watt. Some other Tesoro's used 1N749, which is also 4.3V 1/4 watt. All of the ICs you asked about are powered by +/- 5volts.
Now, about the power supply decoupling capacitors. If you are going to build SS2 yourself, it cannot hurt to add them and would be foolish not to, but that is just my opinion. Tesoro has a lifetime guarantee, so their philosophy may have been to use as few parts as necessary but still get the job done. One shorted capacitor is much easier to find if there are not six or eight others in parallel with it. And, there are six or eight (times two - there are two power supplies) less parts to fail with this approach. Just make sure the PC layought is viable. My PCB is like no other I have ever seen, but from what I can tell - it has no power supply bypass caps except for the large electrolytics. There may be one or two others scattered around, but I'm not going to make sure one way or the other. If you could see my board, you would know why.
Please let me change subject:
Here's something I was going to write about last night but I stopped myself because I had a tough time getting my foot out of mouth from the last time I was here:
People wanting to beef up the power supply voltage may cause the FET stabilization circuit to "saturate" (for lack of better term). A different FET might solve this - 2N4392 for example. Something else that might work is placing a resistor (about <1KΩ I think), in series with the zener. Of course you could also bypass the entire FET circuit. (Look for the Silver Sabre Plus schematic.) I think the FET is in the SS2 (and some other models) to help make the zero crossing detector outputs have more symmetrical waves. But component values are somewhat critical. I want to build a MD with this type oscillator, and I would add accomodation for another 1N4148, and a resistor, and use 2N4392 or 2N4393 (with a ten volt positive supply). Then, use a scope to tune everything.
I have a SS2 that is a little different because it uses SMT and a hybrid PCB. I reference this SS2 schematic, but also the Bandito, and Golden Sabre. My unit's components and circuit falls somewhere in-between these, as near as I can tell. Many components are unmarked or unreadable. Resistors look like ink spots. Is this a "MicroMax" predecessor?
I have posted a picture of my MD. It's called Silver Sabre II, but notice the HCF4016 and two LM308 opamps. I haven't seen any one schematic that cover this model.
Hello Duncan - I know you addressed Merc -
The 1N5229 diode is a 4.3V zener, 1/4 watt. Some other Tesoro's used 1N749, which is also 4.3V 1/4 watt. All of the ICs you asked about are powered by +/- 5volts.
Now, about the power supply decoupling capacitors. If you are going to build SS2 yourself, it cannot hurt to add them and would be foolish not to, but that is just my opinion. Tesoro has a lifetime guarantee, so their philosophy may have been to use as few parts as necessary but still get the job done. One shorted capacitor is much easier to find if there are not six or eight others in parallel with it. And, there are six or eight (times two - there are two power supplies) less parts to fail with this approach. Just make sure the PC layought is viable. My PCB is like no other I have ever seen, but from what I can tell - it has no power supply bypass caps except for the large electrolytics. There may be one or two others scattered around, but I'm not going to make sure one way or the other. If you could see my board, you would know why.
Please let me change subject:
Here's something I was going to write about last night but I stopped myself because I had a tough time getting my foot out of mouth from the last time I was here:
People wanting to beef up the power supply voltage may cause the FET stabilization circuit to "saturate" (for lack of better term). A different FET might solve this - 2N4392 for example. Something else that might work is placing a resistor (about <1KΩ I think), in series with the zener. Of course you could also bypass the entire FET circuit. (Look for the Silver Sabre Plus schematic.) I think the FET is in the SS2 (and some other models) to help make the zero crossing detector outputs have more symmetrical waves. But component values are somewhat critical. I want to build a MD with this type oscillator, and I would add accomodation for another 1N4148, and a resistor, and use 2N4392 or 2N4393 (with a ten volt positive supply). Then, use a scope to tune everything.
I have a SS2 that is a little different because it uses SMT and a hybrid PCB. I reference this SS2 schematic, but also the Bandito, and Golden Sabre. My unit's components and circuit falls somewhere in-between these, as near as I can tell. Many components are unmarked or unreadable. Resistors look like ink spots. Is this a "MicroMax" predecessor?
I have posted a picture of my MD. It's called Silver Sabre II, but notice the HCF4016 and two LM308 opamps. I haven't seen any one schematic that cover this model.
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