This comes from a footnote in the April issue of QST (Page 32):

A technical journal named The WCF Experimenter.

Its Spring, 2016, issue has some interesting projects for both the advanced builder and those with more moderate skills.

One of the latter articles describes an Arduino-based device for measuring the speed of sound at your location, by bouncing sound off a wall and measuring it's return time.

It might be a good anesthetic for cabin fever.

For the benefit of hams who happen to be sighted, here are a couple of posts written by blind hams who routinely use soldering irons. There is more, very positive material, elsewhere on the Web.

The first is a  brief introduction to the subject.

The next goes into more detail.

And finally, some general  ARRL material on the subject of hams who happen to be blind

The point of this post is...in amateur radio soldering, it's often safer if the blind lead the blind.

For the 2016 Wisconsin QSO Party, we operated as N9UW from UW Space Place in Madison, WI again this year.

We used two endfed antennas that were a half wavelength on 80 meters, which made them resonant on 10,15,20,40 and 80 meters. Since the quadplexers are only set up for 15,20,40 and 80M, those were the four HF bands that we operated on. We also used the Space Place 2M vertical, so were able to get some local contacts on 2M.

Our operators this year were Barry K8SD, Thomas, AC9BJ, Carlie KD9CZG, Doug ND9Q, Matt NM9O, Andy AC9CB, Mike KD9BDL, Tom W9TDP, Brian KK4HPY and Nathan KC9WHJ. We operated using SSB, FM, CW and digital (psk31) modes. This was a great learning event as some of our operators had limited HF experience previously.

For logging we used the software created by N3FJP.

We made contacts with 46 Wisconsin counties and 43 states/provinces in North America.

Some pictures showing the operators and station setup.

...continue reading "2016 Wisconsin QSO Party"

Adding letters to capacitor values isn't that complicated; it's just one more little detail to be aware of. The following sums up some basic letter codes for capacitor tolerances:
Some capacitors are defined by a three number code followed by a letter. This letter represents the tolerance of the capacitor, meaning how close the actual value of the capacitor can be expected to be to the indicated value of the capacitor. The tolerances are indicated as follows:
Read B as 0.10 percent.
Read C as 0.25 percent.
Read D as 0.5 percent.
Read E as 0.5 percent. This is a duplication of a D code.
Read F as 1 percent.
Read G as 2 percent.
Read H as 3 percent.
Read J as 5 percent.
Read K as 10 percent.
Read M as 20 percent.
Read N as 0.05 percent.
Read P as plus 100 percent to minus 0 percent.
Read Z as plus 80 percent to minus 20 percent.

The above was copied from this site, which adds a little bit more info.

Next week, we'll talk about more naming schemes, and wind up with a couple of links which illustrate just how (unnessarily?) complex this subject can become.

This is a tiny ceramic capacitor.  You can only read the stuff printed on it under high magnification

ceramic sapacitor01

Let's say that this is the same capacitor, but under high magnification. But what does '104' mean? Is it some kind of model number? Inventory number? Does it mean nothing to anyone but space aliens?

Ceramic capacitor

Nope. It tells you it's capacitance, in picofrads. The first two digits indicate part of it's capacitance value. The third digit indicates the number of zeros which follow the first two digits.

Thus, it's capacitance is 10, followed by four zeros, i.e., 100,000 picofarads (100,000 pF)

You can also just drop the last three zeros and call it 100 nanofarads (100 nF). Both are the same value; they're just  written differently.

You can find out a bit more here.

And even more, in a straight-to-the-point video, here.

This begins a series of posts about stuff which is printed on the outside of capacitors. We'll deal with some of the schemes for indicating mF, uF, nf, and pF.

For our purposes:

1 mF is also known as
one one-thousandth of a Farad
10 to the minus-3rd power of a Farad
0.001 of a Farad
1 millifarad

1 uF is also known as
one one-millionth of a Farad
10 to the minus-6th power of a Farad
0.000001 of a Farad
1 microfarad

1 nF is also known as
one one-billionth of a Farad
10 to the minus-9th power of a Farad
0.000000001 of a Farad
1 nanofarad

1 pF is also known as
one one-trillionth of a Farad
10 to the minus-12th power of a Farad
0.000000000001 of a Farad
1 picofarad

There are much larger capacitor values in other branches of electronics but we don't need to deal with that on a ham radio site.

Next, we begin relating the above definitions to the many codes used by capacitor manufacturers.
Meanwhile, there's more material about similar math notation on Wikipedia.

Appropos of nothing: there are also the mathematical prefixes Zepto- and Yocto-, which are not needed here. They just sound like two long lost Marx brothers. You know, Groucho, Chico, Harpo, Zeppo, Gummo, Zepto, and Yocto.