KØNR: Radio Enthusiast

When I first got started in amateur radio (many years ago), one of the engineers that I was working with at a summer job told me “Don’t get stuck on 2 Meter FM”. At the time I was a college student and felt lucky enough to have 1) found time to pass my Novice exam, including Morse Code test, 2) found time to travel 150 miles to the regional FCC office and pass my Technician exam, and 3) scraped up enough money to buy a basic 2 Meter FM mobile rig. I was in Technician ham heaven, playing around on 2 Meter FM, both simplex and repeaters. Oh, and we had this cool thing called autopatch that let you make actual phone calls from your car. I really wasn’t worried about getting “stuck on two”.

Even though my discussions with this Old Fart Experienced Radio Amateur revealed that he didn’t see 2 Meter FM as Real Ham Radio, I could see that he had a point. Two meter FM is only small part of the ham radio universe and it would be easy to just hang out there and miss out on a lot of other things. I was reminded of this recently by K3NG’s post: Things I Wish I Knew When I Was A Young Radio Artisan. I agree with most of his comments with the exception of this one:

Don’t get your start on 2 meter repeaters.

This took me back to the comments from the Experienced Radio Amateur from years ago. I get the point — starting out on 2 Meter FM and Repeaters can give you a limited view of ham radio — but I see it as the perfect platform for getting started. Here’s what is working in my area with new Techs: get them started with a dualband FM rig (usually an HT) so they have some on-the-air success. This also puts them in touch with the local ham community, where we not-so-subtlely expose them to other bands, modes and activities. They hear the other guys talking on the repeater about working DX on 10 Meters and start thinking about how to pursue that as a Tech. From there, it just expands out to all kinds of bands and modes.

Just for the record, I guess I did follow the advice of the Experienced Radio Amateur and managed to not “get stuck on two” (i.e., I’ve worked all of the bands from 80M to 10 GHz, earning WAS, WAC, DXCC and VUCC.)

73, Bob K0NR

It was time to upgrade my Verizon Wireless phone, so I decided to move to a smartphone. After pondering whether to go with Android or Apple, I finally settled on the iPhone 4. I still miss the The Real Keyboard on my old LG EnV3, as it is nearly impossible to type on a shrunken touchscreen. But then there’s those apps…

I have been trying out some of the ham radio related applications on the iPhone, so I thought I’d report out what I have found.

Here are a few utilities that I found. These apps doing something relatively simple:

CallBook (Author: Dog Park Software, Cost: $1.99) Simple ham radio callbook lookup that accesses the WM7D database (or QRZ and Ham Call databases if you are a subscriber).

Maidenhead Converter (Author: Donald Hays, Cost: Free) Handy app that displays your grid locator, uses maps and does lat/lon to grid locator conversions.

Q Codes Reference (Author: fiddlemeragged, Cost: Free) This app displays the definition of the common Q Signals (QRZ, QSL, QTH, …)

UTC Time (Author: Michael Wells, Cost: Free) A simple app that displays UTC time and local time.

Sunspot (Author: Jeff Smith, Cost: Free) A simple app that displays solar data from WWV.

Ham I Am (Author: Storke Brothers, Cost: Free) A handy app that covers some basic amateur radio reference material (Phonetic alphabet, Q Signals, Ham Jargon, Morse Code, RST System, etc.) Although I find the name to be silly, I like the app!

There are a few repeater directory apps out there:

QSL.FM Mobile (Author: Robert Abraham, Cost: $2.99) Geolocation repeater directory and call sign lookup.

iHAM Repeater Database (Author: Garry Gerossie, Cost: $4.99) Geolocation repeater directory. This seems to work a lot better than the QSL.FM app.

If you are an EchoLink user, then you’ll want this app:

EchoLink (Author: Synergenics, Cost: Free) The EchoLink app for the iPhone.

There are quite a few APRS apps out there. I have tried these:

iBCNU (Author: Luceon, Cost: $1.99) The first APRS app I was able to get running. It just turned on and worked. It integrates the aprs.fi mapping into the app, so it is easy to use. I recommend this one for most casual APRS users.

OpenAPRS (Author: Gregory Carter, Cost: $3.99) This APRS app integrates into the openaprs.net server. A bit more complicated to set up but looks to be more flexible, too. You might want to check out openaprs.net before buying this app.

PocketPacket (Author: Koomasi, Cost: $4.99) another APRS app. Seems to work fine but I find the previous 2 apps more useful. Note: This app can function as a packet modem connected to a transceiver (no internet required).

Ham Tracker (Author: Kram, Cost: $2.99) APRS app, works OK, uses external maps such as Google and aprs.fi. “Share” feature allows you to send an SMS or email with your location information.

Satellite tracking is another useful app for a smartphone:

ISS Lite (Author: Craig Vosburgh, Cost: Free) A free satellite tracking app for just the International Space Station

ProSat Satellite Tracker (Author: Craig Vosburgh, Cost: $9.99) This app is by the same author as ISS Lite, but is the full-featured “pro” version. Although it is a pricey compared to other apps, I recommend it.

Well, that’s what I have found so far. Any other suggestions?

- 73, Bob K0NR

We’ve been looking at optimizing the performance of the D-STAR repeater here in Monument (W0TLM, 446.8875 MHz), so I’ve been searching the web for information on what other groups have uncovered. Not surprisingly, there has been some creative reverse-engineering and re-engineering of the ICOM D-STAR repeaters.

Here’s a summary of some Good Stuff that I found:

1. NU5D paper on DSTAR Repeater Modifications & Interference Testing

2. A good overview of the ICOM D-STAR repeater block diagram and a few modifications to the ICOM repeaters on the dstar.ca web site

3. The N5EBW LED Board – a drop in board to add transmit/receive LEDs to the ICOM D-STAR repeaters

4. The Utah VHF Society D-STAR page — some of the best technical information and practical evaluation of D-STAR technology

5. A Look Inside D-STAR Modulation – an article I wrote for CQ VHF magazine that explains the vocoder and modulation scheme in D-STAR.

If you come across other D-STAR resources, please let me know.

73, Bob K0NR

In a previous blog posting, I wrote about the construction of a portable VHF/UHF crossband repeater. I published the results of this project in my FM/Repeater column for the Fall 2008 issue of CQ VHF Magzine. I’ve adapted portions of the article to provide an update here.

To deal with the issues of identification and control, I decided to use a repeater controller to control two independent 2M/70 cm transceivers. Most repeater controllers are set up for conventional repeater control with a fixed receiver and fixed transmitter. What I needed was a controller that incorporated the concept of two independent transceivers that could be linked together, independently controlled and independently identified. The NRHC-6 Bridging Repeater Controller is designed to handle this specific case of connecting two transceivers. The block diagram of this crossband repeater system is shown in Figure 1.

Figure 1. Repeater system block diagram

I used a pair of FT-7800R transceivers which have a packet port on the rear panel that provides a convenient interface point for the repeater controller. This port has the required transmit audio, receive audio, PTT line and squelch line. The squelch line indicates the condition of the receive squelch, including the effects of CTCSS decode if enabled in the transceiver. (Not all transceivers behave this way… some only provide carrier squelch even if CTCSS decode is enabled.) Table 1 shows the signals available from the packet port and how they are used in the repeater interface.

Table 1. FT-7800R Packet Port

The NHRC-6 controller has a versatile feature set that requires some programming to make it work. It supports two radio ports which can be configured to handle two back-to-back simplex radios. The controller has DTMF control, which can be accessed from either radio port. The five saved setups are handy for storing away specific repeater configurations. Each radio port can have its own courtesy tone and CW identifier, along with the usual set of hang timer, ID timer, timeout timer, etc. The crossband repeater can be turned on and off remotely using DTMF on either band.

Figure 1 shows two separate antennas, one for 2 Meters and one for 70 cm. In most cases, I use one dualband antenna and a 2M/70 cm duplexer to allow the two radios to feed the antenna. I also keep the radios set at less than full power to minimize the heat dissipation problem.

This crossband repeater is housed in a portable case that has standard 19-inch rack hardware (Figure 2). The two transceivers are mounted to a 19-inch shelf using their normal mobile mounts. The NHRC-6 controller has its own 19-inch rack mountable chassis. The case has a front and rear panel covers that snap on, protecting the equipment during transit. The system runs off of 12 VDC. I did not include an AC power supply inside the case. Depending on the location, I simply connect the repeater to a 12 volt car battery or a compact AC switching power supply.

I’ve used this repeater as a standalone UHF repeater by adding a small mobile duplexer to provide transmit/receive isolation. Of course, in this case, the two transceivers both operate on the 440 MHz band with 5 MHz offset. I’ve also used it as a crossband repeater, usually to extend the range of a 2 Meter repeater.

- 73, Bob K0NR

My latest ham radio project is assembling a portable repeater for VHF and UHF operation. The basic idea is to package two VHF/UHF transceivers and a repeater controller into a rack mount box that can be easily transported and powered from a 12 VDC source.

I chose the Yaesu FT-7800R for the transceivers since it covers the 2M and 70 cm bands and has a data/packet port for easy access to the required control signals. Specifically, the data port has transmit audio in, receive audio out, squelch signal and PTT (Push To Talk). The repeater controller used is the NHRC-6, which is designed for use as a bridging controller between two transceivers. Most repeater controllers are set up for a conventional repeater configuration, always receiving on one frequency and always transmitting on another. I plan to use the repeater in this mode (on the 70 cm band, with a small UHF duplexer) but also wanted to run the transceivers in a crossband repeat mode. The NHRC-6 handles this quite well, able to route audio in both directions between two transceivers and with identification support for both rigs.

I’ve got the system assembled and I am playing around with the configuration. More to follow, probably in a CQ VHF article.
73 Bob K0NR