RF App Notes Old, But Certainly Not Obsolete

Although most people now know Hewlett-Packard as a leading manufacturer of computers and printers, old-timers knew them as the pre-eminent maker of electronics test and measurement gear. They actually got started making computers as a sideline. The computers were to be used to control the instrumentation in automatic test setups; they never intended for computers to be their main business.

Old HP Logo
The Hewlett-Packard logo from AN 15, “Distortion and Intermodulation,” published in January 1964.

Computers, especially computer printers, eventually overtook test instrumentation in terms of revenue and manpower. This lead to a desire to split up the company, since the business of making and selling a mass-market product like computers is much different than making and selling precision instrumentation. The split became official in late 1999. The new company was named Agilent Technologies.

Why all the history? Well, Agilent has just posted more than 230 “classic” Hewlett-Packard application notes on their website. Many of these date back to the early 1960s.

They may be old, but they’re certainly not obsolete. For example, the first three listed include:

This material is basic stuff, and just as applicable today as it was in the Sixties. Be forewarned, though. These app notes were written by engineers, for engineers, so the mathematics can get a little hairy. Even so, working through that might be well worth the effort.

Thanks to Chris, KA8WFC, for turning me on to these app notes. As he notes, “One could get a nice RF background just studying these app notes—although having all that sexy test gear wouldn’t hurt!”

Related links:

  1. The Museum of HP Calculators
  2. HP Computer Museum

Miscellaneous Links

Here are some miscellaneous links that I’ve come across lately:

  • Extra Class Math Guide. On the Extra Class test, they actually expect you to know how to calculate things like resonant frequency and phase angles. If you don’t remember your high school math, download this free guide.
  • Nightfire Electronic Kits. Want to start playing around with surface mount devices? Nightfire offers collections of resistors, capacitors, and semiconductor devices, as well as prototype boards. They sell complete kits, too.
  • Hardware Book. This site bills itself as, “The Internet’s largest free collection of connector pinouts and cable descriptions.” Need to know how to wire up an Amiga 500 mouse? This is the site to go to.

DXTuners.Com Free (for a while, anyway)

DX Tuners provide access to a global network of remotely controlled shortwave and VHF/UHF receivers via the Internet. You aune the radios with your browser and get live audio. Normally, you have to pay to get access to all of the network’s receivers, but to celebrate the tenth anniversary of the launch of DxTuners.com, they are opening the network to everyone free of charge.

Check it out. It’s pretty cool.

PIO Tools Available on CD-ROM

From Allen Pitts, W1AGP, ARRL Media and PR Manager:

The Swiss Army Knife for PIOs 2006 edition is available on CD and now there’s also a copy on the internet.

The ‘Knife is a collection of the most used tools, files, and ideas from PIOs around the country. It is the “go to first” place for most of the questions PIOs will have.

Norm Schklar, WA4ZXV, has put the ‘Knife 06 on a website (http://www.wa4zxv.com/sak/sak.htm)! This will allow people who need things in a hurry to get at information. While it is not a replacement for having the disk yourself (the whole idea of the disk was so that people did not have to search through websites or wanted to present parts in a meeting, I definitely DO see it as an answer for people who still have not heard about the ‘Knife and are looking for something immediately.

Actually, the information as well as the entire disk are available there. The site has available the .iso disk image so that you can burn the CD for yourself and for others. Have fun!

More Ham Radio Blogs

One cool thing about having an amateur radio blog is that you get e-mail from people who read your blog. Lately, I’ve gotten e-mail from hams who have blogs of their own. Below, find links to and mini-reviews of these blogs.

The first is the blog of my friend, Ramakrishnan, VU3RDD. I met Ramakrishnan via my blog, and we’ve been swapping e-mail for the past year or so. I’ve blogged about Ramakrishnan’s efforts to get licensed, and now he has a blog of his own. Ramakrishnan’s blog is somewhat like mine, a diary of his activities. He’s a DSP engineer with Texas Instruments in India, so many of his entries are technical in nature.

For example, the entry for April 12 talks about using the TI MPS430 process or amateur radio applications. This was interesting to me as most amateur radio microcontroller applications are now being built around the PIC family of chips. As Ramakrishnan points out, however, the MPS430 may be more appropriate for amateur radio applications. Of course, it is a TI chip, and he may be a bit biased in that direction :), but it does have a lot of features that might make it more useful for hams, such as high-performance analog functions.

The second is bytes and hertz, a creation of Zane, K2DYB. It’s a bit more news-oriented than mine is, and perhaps has a more local focus (Zane lives in western NY), but still an interesting read. I liked the article on the Indian amateur radio satellite. I hadn’t seen that anywhere else. It also has a cool little “Ham Chatterbox” in the righthand column. I think I’m going to add one of these to my blog, but call it “QRM.”

Finally, we have the Alaska Ham Radio Reference. I picked up this link from bytes and hertz. AHRR is a production of KL0RN, and, as he points out in his first post, is dedicated to the “activities and operating modes of hams in the interior of Alaska.” This blog was only recently started, but already has a couple of good items.

Please support these bloggers. If you live in India, western New York, or Alaska, read these blogs and send them items of interest that you think they might want to write about. These ideas will help the blog grow and prosper.

If this keeps up, we may have to start a network for ham radio bloggers. But, where would we have it–20m or Echolink?