AmateurRadio.com

We have quite a few licensed radio amateurs that are members of public safety agencies, including  fire departments, law enforcement agencies and search and rescue. Since they are authorized users of those public safety channels, they often ask this question:

Can I use my VHF/UHF ham radio on the fire, police or SAR channel?

It is widely known that many amateur radios can be modified to transmit outside the ham bands. The answer to this question used to be that amateur radio equipment cannot be used legally on public safety channels because it is not approved for use under Part 90 of the FCC Rules. (Part 90 covers the Private Land Mobile Radio Services.) The only option was to buy a commercial radio with Part 90 approval and a frequency range that covered the desired amateur band. Some commercial radios tune easily to the adjacent ham band but some do not. The commercial gear is usually two to three times as expensive as the amateur gear, and just as important, does not have the features and controls that ham operators expect. Usually, the commercial radios do not have a VFO and are completely channelized, typically changeable only with the required programming software.

The situation has changed dramatically in the past two years. Several wireless manufacturers in China (Wouxun, Baofeng, etc.) have introduced low cost handheld transceivers into the US amateur market that are approved for Part 90 use. These radios offer keypad frequency entry and all of the usual features of a ham radio. It seems that these radios are a viable option for dual use: public safety and amateur radio.

Here is a short list of the most common radios on the market:

Model	Features	Price
Wouxun KG-UV2D, KG-UV3D	Several different models with slight variation in features, check carefully before ordering 136-174/420-470 MHz 5 kHz is smallest frequency step	$120
Wouxun KG-UV6D	Several different models with slight variation in features, check carefully before ordering 136-174 / 420-520 MHz 2.5 kHz frequency step	$175
Baofeng UV-5R, UV-5RC	The UV-5RC is an updated case style 136-174 / 400-480MHz 2.5 kHz frequency step	$65

 Some Things to Consider When Buying These Radios

• The manufacturers offer several different radios under the same model number. Also, they are improving the radios every few months with firmware changes and feature updates. This causes confusion in the marketplace, so buy carefully.
• Make sure the vendor selling the radio indicates that the radio is approved for Part 90 use. I have seen some radios show up in the US without an FCC Part 90 label.
• Make sure the radio is specified to tune to the channels that you need.
• The 2.5-kHz tuning step is required for some public safety channels. Your particular set of frequencies may or may not need it.  For example, a 5-kHz frequency step can be used to select frequencies such as 155.1600 MHz and 154.2650 MHz.  However, a 2.5 kHz step size is needed to select frequencies such as 155.7525 MHz. There are a number of Public Safety Interoperability Channels that require the 2.5-kHz step (e.g., VCALL10 155.7525 MHz, VCALL11 151.1375 MHz, VFIRE24 154.2725). The safest thing to do for public safety use is to get a radio that tunes the 2.5-kHz steps.
• Although these radios have two frequencies in the display, they only have one receiver, which scans back and forth between the two selected frequencies. This can be confusing when the radio locks onto a signal on one of the frequencies and ignores the other.

Recommendation

I own 3 different models of Wouxun radios and two Baofeng UV-5R radios. I think they are all great radios for what they do. For serious public safety use, I would recommend getting the Wouxun KG-UV6D with the 2.5-kHz frequency step. The controls of the Wouxun are superior, including a knob for channel/VFO selection and RPT key for changing repeater shift. The Wouxun software works much better than Baofeng’s (which is really a mess). Also, if you show up at an incident with the Baofeng, your fellow first responders will think it is a toy.  If you are absolutely sure you don’t need the 2.5-KHz frequency step, then you might consider one of the other Wouxun models.

I have purchased several radios from importcommunications.com and have been very satisfied with the service. You may want to shop around for the best price.

73, Bob K0NR

Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

Recently I came across my old RTTY hamcom modem when cleaning my garage. Built from scrap parts and inspired by Peter PA1SDB at the time we were both experimenting on CB. I even remember we transmitted kind of a RTTY bulletin on CB every sundayevening at that time. And after we got our licenses we regulary were found on the 2 Meter band receiving the local World Link RTTY bulletin by PA3ESF. Most of the HAMs involved used software called Intercom by PA3BYZ at that time. All nice RTTY memories for me, but things can get more crazy as before my first efforts with RTTY and before my time there were the old mechanical  Telex machines. There are still HAMs like PE1ARD Arnold who have these telex machines working and use them in their radioshacks, incredible! Find a video here: http://youtu.be/ku_JlxlTLIA and take a look at around 10:40. And so….we’re doing a RTTY contest these days on HF. A antique mode used to do contest inspired by the past I think. As there is a large number of stations participating it is very populair. not really my mode outside contesting, I prefer something modern like PSK or JT65. Most interesting RTTY contest is probabely last weekends CQWW RTTY contest which has lots of DX stations that participate. Unfortenately I had less time Saturday and in the evening 10 and 15m were closed. So I made some QSOs on 80, 40 and 20m. Sunday was better and I could attend the shack in the morning with my harmonic Anneli. When starting the computer I checked the 11m band as always to check propagation possebilities on 10m. I heard an old CB radio friend and made a QSO with him first. After that I moved to 10m and made my first QSO to Japan, the next station was my neighbourstation PA0O Jaap. I made a small sked with Jaap on 70cm FM, Jaap told me that propagation would be not as good as saturday because of a magnetic storm. He told me also he heard Hawaii and Guam on 10m, but it was hard to make the QSO because of the pile-ups. So unfortunate I thought I was too late for DX….well after all I think I did make some:

10m RTTY most interesting DX worked: JR4GPA Japan, KG6DX Guam, NH2T Guam, P49X Aruba, FM5CD Martinique, FR5GS Reunion isl., AY8A Argentina, CW90A Uruquay, 4M5IR Venezuela, HK1R Colombia, HI8PLE Dominican Rep., PY2NY Brazil and of course lots of USA and Canada both east and west coast.

Bas, PE4BAS, is a regular contributor to AmateurRadio.com and writes from Groningen, Netherlands. Contact him at [email protected].

Good mushroom, everyone, and welcome to another episode of Linux in the Ham Shack. This time around, we get a little bit ham geeky. That’s not a bad thing for those of you who are computer enthusiasts. We all delve into some scientific topics like electro-magnetic radiation, skywave propagation, atmospheric layers and other topics that are sure to tickle a few neurons and axons. We manage to keep everything at a level even non-geek-weenies will be able to understand. Somehwere in the middle, Russ goes on a tirade so you don’t want to miss that either. While you’re listening, take a moment to click on a link or two, sign up for the mailing list or maybe donate a couple of bucks to the show. We will love you long time if you do. Promise.

73 de The LHS Guys

Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

Recently it’s been quiet here on Radio Artisan and I’ve been somewhat absent on AmateurRadio.com.  The usual excuses apply, with work consuming most of my intellectual energy and time.  It’s unfortunate we have to work so hard to live and have some fun.  In this culture we seem to be on an endless treadmill that goes faster and faster, but goes nowhere.  But needless to say I’m still alive and have been actually doing some amateur radio stuff these days.

Daily I receive correspondence about my CW Keyer and Rotator Controller, most of it coming from Europe and Australia.  Originally with the Rotator Controller I just wanted to interface my Yaesu rotator to the computer, but it’s gone beyond the original scope with notes from folks interfacing homebrew rotators and some amateurs with really cool ideas.  I continue to write bug fixes and minor feature updates for the CW Keyer, which now has two parties offering hardware kits.

The main project garnering the most attention right now is the Arduino Antenna Tuner.  It’s going slower than anticipated, but I’m pleased to say I’ve been making some progress with a good portion of the tuning network built, the I2C interface hardware working, and the frequency counter prescaler built on the hardware prototype.  I’m currently working on an SWR bridge and I’m having some issues.  I’ve built a Bruene bridge and a Tandem Match bridge, and both have rather mediocre directivity, in the neighborhood of 12 to 14 dB.

Both of my SWR bridge prototypes are “good enough” to use for software coding and testing, however I want the final product to be better.  Any feedback from anyone with hands-on experience building SWR bridges would be appreciated.  Once I get the hardware prototype to a reasonable level, I can dive into the coding.  Some of this work was completed earlier this year as I wrote some SWR reading and calculation subroutines and some LCD interface code.  I’m really giddy to get coding. Although I really like building stuff I guess I’m more of a software guy than hardware.  I find algorithms, protocols, networking, and interfacing exciting.

I continue to enjoy working with folks, helping them get code working and talk about ideas.  It’s neat to be able to email someone halfway around the world a code snippet and have them load it up on their hardware, use it, and have fun with it.  Although the Internet has made the world seem smaller, and amateur radio is no longer the only way to talk to folks in far off lands, amateur radio adds another dimension to the Internet and vice versa giving us more opportunity to help each other and promote international goodwill.

KX3 serial number 1990

The KX3 is all together now and there was some bumps in the road and I will share them in a later post. I still have to calibrate the roofing filter I will be using my Elecraft XG2 to do this but this may have to wait for another day. I have been hidden away in my radio room for a day and a half. The build took longer as I was videoing the process. The video will be divided up into segments of the build........see how it turns out.
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

If you have been following my adventures, specifically with the Etherkit OpenBeacon, you will know that I was investigating a method of triggering WSPR transmissions without leaving it attached to a computer.  My requirements were that it be Arduino based, since I am learning about that as well, and have a very stable time source as necessitated by WSPR.

The available options for stable time sources in the Arduino time library include NTP, RTC, and GPS sources, I decided to go a different direction!

While investigating time sources I ran across the WWVBClock Project on Github and thought WWVB would make an interesting time source for this project.  The first step was to find a receiver, which are far less common from online shops than I expected, but I was able to find one at my local Wal-Mart in the form of a self setting alarm clock for the reasonable cost of $10.

As soon as I got home I opened it up to ensure that the module was not integrated into the main PCB as that would be of little use and to my delight it was a separate unit as shown below. It is the module on the left hand side of the larger PCB and the antenna is located at the top.  A pair of cutters and one minute later, I had a WWVB receiver module.

Locating a datasheet for the module proved a little challenging, but I was able to locate the datasheet for IC used on the module, which is located here.

Having all of the necessary information, it was time to start playing.  I breadboarded all of the components as show in the schematic and started hacking apart the code from the WWVB Clock Project.

My initial plan was to use the WWVB receiver and the Arduino time library to set the internal clock with hopes that it would keep accurate time when a WWVB signal wasn’t available.  This proved to be a lost cause as it was 4 seconds behind after 90 minutes without a WWVB signal, far beyond the 2 seconds of accuracy required by WSPR.

The second, and current implementation, only transmits when a WWVB signal is available to guarantee accurate timing.  The code by default will transmit at 4 minute intervals, but this value is configurable by manipulating the triggerInterval variable.  During normal operations the code displays, via the serial port, each time an output signal is sent, enabling you to not only track transmissions, but also the availability of the WWVB signal in your area.

Here are the spots as reported on WSPR for the last 24 hours all of which have been triggered by this project.

This project has been a lot of fun and works quite well!  A WWVB signal is consistently available here in Central Arkansas, in the Central time zone, from about 7PM through the 10AM, honestly much more than I expected.  The code for the project is available on Github, so feel free to use it and experiment!

 

Robert Garcia, K5DTE, is a regular contributor to AmateurRadio.com and writes from Arkansas, USA. Contact him at [email protected].

With the Wouxun dual band mobile rig here to be reviewed for Practical Wireless, I thought I would pop it in the car for a week or so. I did that yesterday and took the FT8900 out of the car. Since all the connections are the same as the FT7900 I use in the shack for 144/432MHz FM, I thought I would use it in the shack.

It seems to be working well, and nice to have 50MHz on it too, though no 50MHz FM QSOs yet. I’ve a couple of memories set up for 29MHz and though it’s only on the 50:144/432 MHz collinear, good signals have been coming through on 29MHz FM.

More of course on the Wouxun in Practical Wireless!

Tim Kirby, G4VXE, is a regular contributor to AmateurRadio.com and writes from Oxfordshire, England. Contact him at [email protected].