n00b questions alert

[Grahame]

I have a basic question. Should I put the mayo between the bread and the ham, or between the ham and the salad?

From Alton Brown's unified theory of sandwich physics.

Corollary 2: When wet ingredients, such as tomatoes are used, a thin coating of mayonnaise, butter, cream cheese or oil should be applied to the bread as a moisture barrier.

so: when using wet ingredients apply a moisture barrier

From Here: SandwichCraft Transcript

Much, much more good eats stuff here: Good Eats Fan Page

[guzziguy]

I have a basic question. Should I put the mayo between the bread and the ham, or between the ham and the salad?

Neither, you should be using mustard instead of mayo.

[fordgtlover]

Here's a web article I found useful in the past. It's called Replacing Passive Components to Improve Sound Quality, which seems relevant to the OP. It has a section on resistors.

http://www.geocities.com/Area51/Nebula/3736/improve_audio.txt

Here's some information form Tangent's website that pretty much addresses the issue of resistor symmetry.

Hand-Matching Resistors to Tighter Tolerances

[TomB]

No, just simplicity, and less arguing the intricacies of theoretical stuff us nubs don't understand anyway We want basic answers to basic questions.

Sorry, I'm not trying to start anything, but the first response you got to your question in this thread had the potential of leading you astray. Yet, considering the estimable reputation of that source, we were trapped into citing real documents to get you back on the right path.

Put simply: stay with 2X on sizing resistors for power rating and stay with metal films (preferrably Vishay-Dales) to reduce the noise to the least amount possible. Also note that V-D resistors are typically already over-rated at 2X on power.

If you start asking about boutique resistors, then it's another issue entirely and opinions will be all over the map.

Hope that was simple enough ...

[Smeggy]

Thanks Tom, yes simple is good or my old pea brain gets confused.

Next Q

What in basic terms does cascoding mean and do? I hear it bandied about frequently and when I look it up on wikipedia it explains it with more jargon

[Beefy]

What in basic terms does cascoding mean and do? I hear it bandied about frequently and when I look it up on wikipedia it explains it with more jargon

I don't fully understand it, but think I can summarise the wikipedia for you.

Imagine you want to amplify a small signal in a circuit. You can just pop a single transistor in the circuit and it will work, but not great, because you also amplify the small capacitance present in the transistor.

But if you use two transistors together in a cascode you don't amplify the capacitance so it potentially works much better.

[Smeggy]

Ta Beefy

[Smeggy]

Next question, those little flat rubbery insulator sheet thingies that go between mosfet and heatsink, what are they called as I need some

[luvdunhill]

Next question, those little flat rubbery insulator sheet thingies that go between mosfet and heatsink, what are they called as I need some

Generically, they are called heat sink pads. They come in all shapes and sizes. Most likely you want electrically isolated pads. Here's the catalog page at Digikey that is most appropriate:

http://dkc3.digikey.com/PDF/T091/P1177.pdf

Aavid Thermalloy also makes some that are sold at Mouser.

If you need onesy-twosys, PM me your address and I'll drop them in the mail

BTW, the 6-pin socket arrived and my template is slated to arrive today... so once I get home, we'll see how it fits!

Edited March 31, 2009 by luvdunhill

[Smeggy]

Cool, thanks marc. I need a pair for another starving student.

[Pars]

You will likely also need the nylon shoulder washers that insulate the screw from the device tab (if metal). Ratshack sells these TO-220 Mounting Hardware - RadioShack.com

[Smeggy]

Thanks very much. I was in rat shack last week hunting for these with no luck. It's a small shop.

[Pars]

Well, I neglected to mention that at $2 apiece, they are a rip. But, in an emergency...

Mouser catalog page showing shoulder washers, mounting kits, etc.

http://www.mouser.com/catalog/637/1936.pdf

[Smeggy]

Yeah, and quicker than some other places

[spritzer]

You can also just use good old fashioned heat sink compound if the transistors have a plastic back. Just remember, less is more with that stuff.

[swt61]

BTW, the 6-pin socket arrived and my template is slated to arrive today... so once I get home, we'll see how it fits!

Dr. Wood will prep the O.R. for Teflon surgery, stat!

[luvdunhill]

Yeah, and quicker than some other places

I got those phenolic shoulder washers too... Looking for the envelope now with your return address. How many do you need? I have lock washers and socket head screws as well... anything else you need?

[Smeggy]

Ok, well if you have some spare I need two for a starvin student thanks

[swt61]

I got those phenolic shoulder washers too... Looking for the envelope now with your return address. How many do you need? I have lock washers and socket head screws as well... anything else you need?

Do I need some of those for the mos fets on the F5?

[luvdunhill]

Do I need some of those for the mos fets on the F5?

I dunno, budding DIYer, do you?

[swt61]

Yes, damn it!

[Smeggy]

hehe

[luvdunhill]

Yes, damn it!

heh.

If you look at the front and back of your transistors, you'll see that everything is rather isolated.. i.e. no metal on the top or inside the hole. If you look at the transistors on the Millet, you'll see there is a metal tab. If you look at the datasheet for those transistors, you'll see the tab is tied to one of the three pins and ultimately to the circuit. They is why they need to be isolated.

[swt61]

So I just flunked my first exam huh?

I better study up for the next one.

[Beefy]

Or you could always just hit the examiner over the head with a lump of wood.