AM/FM antenna ICs deliver a variety of integrated features

From EEProductCenter.Com:

An active antenna IC designed for AM/FM car antenna applications, the ATR4252 from Atmel Corporation is a highly integrated device that offers a host of features including automatic gain control (AGC), supply voltage regulator with overvoltage protection and an antenna sensor.

Designers can now develop smaller, high-performance active antenna solutions for applications located in the mirror, bumper, rear or side windows of a car. In addition, the antenna detection functionality is ideal for modern window or glass antennas. The robust IC also addresses other antenna types including window, pole or shark fin antennas with its small 4 x 5 mm footprint.

The chip is designed to provide low-noise and high linearity to ease antenna system design complexity. On-chip voltage regulation is an important feature when un-stabilized phantom feed is used, and 50 Ohm cable support enables more cost-effective cables to be used. Further, on-chip AGC avoids problems with large signals, while maintaining a high sensitivity level.

“Active antenna designs using ICs are becoming more popular since they offer many advantages over discrete solutions,” said Carsten Friedrich, Marketing Manager for Car Radio ICs at Atmel Corporation.

The antenna IC ensures crystal-clear reception without distortion even under extreme difficult and rapidly fluctuating field strength conditions typically found in moving antenna systems. In addition, board design can be extremely small and the ICs provide a rich set of features, including ESD protection.

I scanned the data sheet, and it says,

AM means long wave (LW), medium wave (MW) and short wave (SW) frequency bands (150 kHz to 30 MHz) that are usually used for AM as well as for DRM transmissions, and FM means any of the world wide used frequency bands for FM radio broadcast (70 MHz to 110 MHz).

Sooooo, some enterprising ham could probably design an active receiving antenna for the shortwave bands around this chip.

TenTec Release the 610 USB Keyer/Audio I/F

In a previous post, I mentioned the TenTec 610 USB Keyer/Audio Interface. I called it “elusive,” but apparently it’s now been released. The TenTec website notes, “When the 610 is used with a CW paddle, it will decipher the CW being sent and turn it into keyboard codes that are sent to the PC.”

If they can do it, I can do it, and I think this would be a cool application for the Bare Bones Arduino microcontroller that we built at our ham club’s meeting last month. I’d like to take this a step further and use it as a general text input device on my Mac.

The cost of the 610 is $169. This still seems a bit high to me, but it also includes an audio interface, so that you can use standard headphones and microphones for remote operation. The audio interface must perform the A-D and D-A conversions needed when using conventional headphones and microphones.

NIST Updates Popular Guide to Radio-Controlled Clocks

From the 9/22/09 edition of NIST TechBeat. I haven’t read this yet, so I’m not sure how much application this information has to ham radio, but I love these clocks….Dan

The National Institute of Standards and Technology (NIST) has updated its popular guide to radio-controlled clocks. Many millions of radio-controlled clocks, watches, and other timepieces are automatically synchronized to official NIST time through special NIST radio broadcasts. The guide is intended to help manufacturers develop reliable and usable radio-controlled clocks, and help consumers select appropriate products, learn how they work, and troubleshoot reception problems.

In the United States, the signals received by radio-controlled clocks originate from NIST Radio Station WWVB, located near Fort Collins, Colo. When working properly, radio-controlled clocks always display the correct time and date, down to the exact second, and never require adjustments. Radio-controlled clocks are automatically updated for such changes as Daylight Saving Time, leap years, and leap seconds.

The updated guide contains a number of changes, including the revised rules for Daylight Saving Time, corrections in time zone tables, and several new recommendations for manufacturers. The guide also lists the latest WWVB specifications, several of which were changed—broadcast power was boosted, for instance—to make radio-controlled clocks work better.

The guide is among NIST’s most requested publications. Each year, the guide is downloaded from the NIST web site about 100,000 times, and an additional 500 hard copies are disseminated.

WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers and Consumers (2009 Edition) is available online. You may also receive a printed copy by sending your mailing address to or calling (303) 497- 4343.

“Choosing a Radio” Guide Now Available

From the May 2009 issue of the ARRL E-Newsletter for Registered Instructor and Teachers:

As I reported earlier, the ARRL began developing a guide to help new hams choose their first radio at the urging of licensing instructors generally, and with special impetus from David Haycock, KI6AWR and Greg Widin, K0GW. The guide was recently finalized, and will be included as a supplement in the next printing of the 1st edition of the Ham Radio License Manual that has just recently gone to press. It also has been posted on its own Web page, where it is accessible to any member. Check it out!

Good Things Come in Small Packages…

…or in this case at small hamfests.

Yesterday, I attended the hamfest of the Chelsea ARC. As hamfests go, this is generally a rather small one. As far as the fun I had there, it was a great, big one.

I drove over there with Jim, K8ELR. It was cool, and it looked like it was going to rain. I checked the weather report, though, and it looked as though the rain was going to hold off, so when we got there, we opted to set up outside and sell out of the back of the van.

Almost immediately, we had guys making us offers. They were pretty low, though, so I put most of them off until after 8 am. After that, things started to move pretty fast. I sold a bunch of books, an old Radio Shack 2m radio, the MFJ antenna tuner and MFJ keyer that had been donated to the Ham Radio at the Hands-on Museum project, and one of the el-cheapo Harbor Freight DMMs among other things.

Jim and I swapped a couple of things. He had a nice, chrome-plated Bencher paddle that he purchased on Ebay that he sold me for $50, and I sold him an old Radio Shack scanner that someone had donated for $10.

In addition to the Bencher paddle, I also acquired a couple of things from Mark, W8FSA. He had a box of random junk, which we sold from our table. From Mark, I got an in-the-box Simpson meter ($4) and a “beam filter” ($2, picture at right). According to WB8TKL, this is a passive audio filter that used to be used in airplane navigation systems. They were apparently used by ham radio operators as a poor man’s CW filter.

The best acquisition, though, was an Optoelectronics frequency counter. Mark was only asking $2 for it. It came with a wall wart power supply, so I took it into the pavillion and plugged it in. All the LEDs lit up, so I bought it. I cleaned it up when I got home, stuck a wire into one of the inputs, and got it to measure the output frequency of my IC-746PRO. Looks like a great buy for two bucks.

The most fun was had, however, meeting and talking to everyone. At one point, our table became a defacto club table. Not only were we selling Mark’s junk, but we had several members hanging out with us. Now, I can’t wait for the Monroe Hamfest, which is going to take place in two weeks.

More Stuff I Gleaned from Twitter

Here are thee more items I discovered via Twitter:

  • Ham Mag #6. The June 2009 issue of this free electronic magazine is now available for download (it’s a PDF file). This issue includes articles on a QRP transceiver for 20m, a 10m rubber duck antenna for the FT-817, and Chuck Blaney, a WWII radio operator.
  • Why Join a Ham Club? This article from the ARRL website makes the case for joining a ham club. It could be a little more detailed, but hopefully it will get more newcomers to join clubs.
  • Tesla Coil @NLL 3/3. This video shows Greg Leyh’s 40kW 11-foot secondary Tesla Coil operating at NLL in San Francisco for DorkbotSF Jun 4 2009. Very impressive.

My Twitter id is kb6nu. If you follow me, you’ll get tweets notifying you of new blog posts, plus various musings on band conditions and the contacts I make.