S-PRE-2

[John Bourke]

A few questions about the S-PRE-2 kit.  Hopefully Kevin can help here.

I'm stuffing the board, and I have ended up with two capacitors that I'm not 100% on.
   

Markings are (as far as I can tell) 471J on the blue green one, and 0.47 J100 on the red one.  The board has spots for a 470p (C7) and a 470n (C9).  My assumption is that the 0.47 on the red one is 0.47 microfarads, which means 470Nanofarads, and it is C9, which leaves the blue green one for C7.

Also - I assume there's nothing keeping me from doing the tube sockets off board?  Is 20AWG stranded good enough for that?

[K O'Connor]

Hi John

Why assume anything? ... although you have made the correct inferences.

Standard prefixes are given in RSG (Ready, Set, Go) and across the web. In electronics, it is extremely bad form to begin a value with a zero or a decimal as the value may be interpreted an order of magnitude high or low if the decimal is not obvious, as with photocopying, for example.

The desgnator for the prefix is used as the decimal holder in values with fractions, such as 2k2 for a 2,200-ohm resistor.

Also note that the prefixes are case-sensitive. For example 'm' is milli and 'M' is mega. Using an ASCII keyboard, 'u' is used for micro as the Greek mu is not available on such a keyboard.

RSG also lists standard values and how values are depicted on different components. cap values when printed numerically use picofarads as the unit, then three digits to express the value. The first two digits are the numeric portion; the third digit is the number of zeros after the numbers. "471' is then 47 followed by one zero, as 470p, so the green cap marked 471J is 470p