Author Archives: Bob K0NR

K0DK: High-Efficiency HT Antennas

Posted on by

It is well known that the standard “rubber duck” antenna that is supplied with a handheld VHF or UHF transceiver is not very efficient. It represents a compromise between size and efficiency, with size winning out. In other words, the antenna is small and doesn’t radiate very well.

I just came across an article by Dick Kiefer (KØDK) that explores this issue in detail, including a design for a 1/2-wave antenna for handhelds. I’ve been a big fan of telescoping 1/2-wave antennas. They are excellent performers while still being light in weight and compact for hiking and backpacking.

Brief highlights of the KØDK article:
For 2 Meters, a 1/2-wave antenna performs ~5 to 8 dB better than a rubber duck.
For 70 cm, a 1/2-wave antenna performs ~3 to 7 dB better than a rubber duck.

Not too surprisingly, the 70-cm (440 MHz) rubber ducks did a little better than their 2-Meter equivalents, since an antenna of a given physical length will be longer in terms of wavelength at the higher frequency.

Take a look at the article for more details.

73, Bob K0NR

January VHF Sweepstakes Results – QRP

Posted on by

The results for the 2006 ARRL January VHF Sweepstakes were published in the July 2006 issue of QST. I’ve listed the Single Operator Portable (AKA QRP) scores below. My totally wimply score of 544 gave me 10th place in the overall contest. Of course, I dominated the Colorado section, which is easy to do when you are the only contest entry. The important thing is that I had a good day playing radio in the mountains. See my previous posting about this QRP backpacking contest effort.

Take a look at my soapbox comments (and photos) at the ARRL web site.

73, Bob K0NR

# Call Score Section
1 KA1LMR 45,504 NH
2 K6MI 36,427 SCV
3 W9SZ 4,875 IL
4 KI7JA 3,040 OR
5 W6DWI 2,106 ORG
6 WB2AMU 1,577 NLI
7 N8XA 1,156 OH
8 KG6TGI 736 ORG
9 KQ6EE 728 LAX
10 K0NR 544 CO
11 N7IR 192 AZ
12 N3TEP 160 WPA
13 KC2JRQ 108 NLI
14 N1ZGY 45 EMA
15 NU0C 36 NE
16 WA7VHF 20 AZ
17 VE7VIE 18 BC
18 WB0IWG 16 WPA
19 KC9FVW 15 WI
20 W6NCT 6 SB
21 KZ1AMY 1 VA

2006 Colorado Section Amateur Radio Operator of the Year

Posted on by

I received this honor at Hamcon Colorado at Estes Park. Thanks to the Technical Specialist team in Colorado for all they have contributed. See http://www.k0nr.com/ts.html

– 73 Bob K0NR

From: ‘ARRL Web site’ To=memberlist@www.arrl.org>
Sent: Thu, 15 Jun 2006 15:54
Subject: Bob Witte, K0NR: 2006 Section Operator of the Year

Bob Witte, K0NR of Monument has been named the 2006 Colorado Section Amateur Radio Operator of the Year. The announcement came at the Saturday evening banquet during the HAMCON 2006 Convention in Estes Park on June 10th. Bob is currently the Colorado Section Technical Coordinator and has been instrumental in building the cadre of Technical Specialists to over 20 individuals who are available to assist League members resolve technical problems. Bob also leads the Colorado BPL Team which keeps an eye out for any mention of BPL depoyment throughout Colorado. A well-known VHF contester, he currently writes a columns for CQ VHF and QRP Quarterly.

Please join me in congratulating Bob on this well-deserved achievement.

73,
ARRL Colorado Section Section Manager: Jeff Ryan, K0RM k0rm@arrl.org

Ten Uses of a Digital Multimeter in Ham Radio

Posted on by

The handheld digital multimeter (DMM) is a basic tool for ham radio applications. Here is a list of 10 things you can do with a DMM.

1. Check the power supply voltage on the new power supply you just purchased.
2. See if your HT battery pack is fully charged.
3. Measure the current that your transceiver draws to estimate how long your emergency power system will last during a blackout.
4. Sort the bag of resistors you purchased at the swapfest.
5. Check a fuse to see if it is blown.
6. Troubleshoot your broken rig by checking the bias voltages against the service manual.
7. Figure out if the AA batteries the kids left for you are dead.
8. Verify that your coax is not shorted between the shield and center conductor.
9. Check the level of the power line voltage in the ham shack.
10. Check for good DC continuity between the ends of the TNC cable you just soldered.

Let me know your ideas to add to the list.
73, Bob K0NR

More on FRS radios for emergency use

Posted on by

Hartford, CT (PRWEB) May 3, 2006 — The Midland Radio Corporation, REACT International, the DC Emergency Radio Network, and NationalSOS.com have jointly announced their support for the National SOS Radio Network — www.NationalSOS.com — a free communications network based on the estimated 100 million FRS-compatible radios already in the hands of the public… and growing by up to 12 million radios per year.

This idea first surfaced after hurricane Katrina. I wrote about it in October 2005, but I haven’t heard much additional news until I noticed this press release. Having REACT and Midland supporting this idea will certainly help, but it is still not clear where this will head, if anywhere.
73, Bob K0NR

The Wilderness Protocol

Posted on by

From the emcomm.org web site:

“The Wilderness Protocol” (ref. June 1996 QST, page 85), recommends that stations (both fixed, portable or mobile) monitor the primary (and secondary if possible) frequency(s) every three hours starting at 7 AM local time, for five minutes (7:00-7:05 AM, 10:00-10:05 AM, etc.) Additionally, stations that have sufficient power resources should monitor for five minutes starting at the top of every hour, or even continuously.” The primary frequency is the National Calling Freq…146.52 MHz. The secondary freqs. are 446.0, 223.5, 52.525 and 1294.5 MHz.

Here in Colorado, the summer months mean that many people head for the mountains. Mobile phone coverage has improved in many parts of the high country but is still not reliable in all areas. Ham VHF repeater coverage is extensive but also does not cover the entire state. This is where the Wilderness Protocol comes into play.

Let me take the liberty of modifying the Wilderness Protocol for use in Colorado:

Principle #1: Don’t ever rely on a radio or mobile phone to get you out of trouble in the backcountry. Your primary strategy must be self-sufficiency. Avoid trouble. Be prepared for the unexpected.

Principle #2: In remote areas, monitor 146.52 MHz as much as possible. This applies to backcountry travelers, mobile stations and fixed stations.

Principle #3: Know what repeaters are available in your area. The Colorado Connection is a linked repeater system that covers many (but not all) remote parts of the state.

Just my opinion.
73, Bob K0NR