AmateurRadio.com

Now that solar cycle 24 is definitely underway, it’s good to be able to monitor what the sun is doing since as hams, it dramatically affects our ability to communicate. I’ve used dx.qsl.net/propagation/ for a long time as a site that I can go to for a quick overview of what’s going on, but for more in-depth information I’ll stop by solarham.com (aka http://solarcycle24.com). Kevin, VE3EN put this site together in 2006 to track the status of the then-upcoming solar cycle 24, and he’s kept improving it since then. On that site, there’s information about the current solar conditions (flux, sunspots, flares, etc.), historical data (such as the chart I’ve included in this post), solar images, and a message board where there are some fascinating discussions, many by recognized experts in their field. Kevin’s even built a version of his site that’s perfect for viewing on mobile devices, so you can view it while on the go.

Kevin’s been funding this site primarily on his own since it’s inception, although he does have a way to make a donation if you so choose. He’s been very low-key about this, but on a recent visit, I saw that he’s got an impossible-to-miss banner up on his website asking for help. Apparently his full-time job has been “off-shored” and he’s not sure that he’ll be able to keep the site available. If you click on that link it will explain the situation more fully. I have no interest in this site other than as a visitor, but if you find it useful, you might want to consider making a donation to help keep the site (and Kevin) going.

Ever since my outing on to Ling Fell yesterday I have been bugged by not knowing for sure whether the problems I experienced with the VX-8GR were really caused by receiver overload or blocking. I like the construction and features of the Yaesu. But a radio that makes you miss some of the contacts you have laboriously sweated up a summit to make is about as much use as a chocolate teapot. I wondered if I could devise a test to give me an idea of the relative strengths of the different 2m radios. I did, and the candidates are lined up in order of merit below, the worst on the left and the best on the right.

The test methodology was crude. I connected each radio to my dual band vertical and tuned in a weakish station: the GB3AS repeater on 145.600MHz, which is normally an S3 signal – fully readable but with some background noise on the audio. I then transmitted a carrier on 144.025MHz using another radio on a helical antenna a few metres from the vertical. I tried two power levels of the interfering signal, 3.5W (“high power”) and 0.5W (“low power”), these being the available power levels of the test radio. This 8dB difference in the interfering signal level had different effects on the ability to receive the repeater signal.

I am well aware of the limitations of the test I carried out. In real life SOTA or WOTA use a radio may be subjected to strong in-band signals from activators on other summits but they will not be as strong as the signal from a radio a few metres away from the antenna. A radio is likely to be subjected to strong signals from outside the amateur band such as pagers and other commercial signals, which the bandpass filters in modern radios due to the marketing-driven necessity of providing wideband receive coverage will do nothing to attenuate. Many strong signals may mix together to cause intermodulation effects if not blocking. However, a receiver that can handle a strong in-band interfering signal is likely also to be better at coping with many strong signals being received over a range of frequencies. So I think my test results have some validity.

Beginning with the worst receiver, the results are as follows.

• VX-8GR. This receiver was the worst affected by blocking. Noticeable desensing of the repeater signal occurred when the in-band carrier was on low power, while a weak noisy “4 by 1” signal was killed completely. The repeater signal cut out completely when the in-band carrier was keyed on high power. Engaging the RX ATT (menu option 1) caused the repeater signal to drop below the squelch threshold so it was not much help though it did reduce the desensing effect on stronger signals.
• JMT-228. The VX-8 was slightly worse than the Jin Ma Tong JT-228, a £30 Chinese handheld bought on eBay. In fairness, the JT-228 is slightly less sensitive than the Japanese ham radios (judging by the signal to noise ratio on weak signals) which may have helped it a bit. Desensing was noticed when the in-band carrier was on low power, and the repeater signal cut out when it was on high power.
• TH-D72. The Kenwood TH-D72 may only be third worst (or third best) but in fact it was a whole lot better. No detectable desensing occurred when the in-band carrier was on low power. Some desensing occurred, in the form of a drop in S-meter reading and increased noise on the audio, when the carrier was on high power.
• GP-300. Excellent performance was given by the Motorola GP-300. No desensing was noticed when the in-band carrier was on low power. There was a very slight but hardly noticeable increase in background noise level when the carrier was keyed on high power.
• TH-205E. I bought this old boat anchor as a “spares or repair” radio for £6 on eBay for the fun of seeing if I could get it going. With the high capacity battery pack it is about the weight and bulk of an FT-817 and not something I would particularly want to haul up a summit. But no desensing of the repeater signal was observed even when the in-band carrier was keyed on high power, making this the best performing receiver of all.

Out of interest I also carried out the test on my FT-817ND and the Kenwood TM-D710 I use as my 2m base station. The FT-817ND was slightly better than the TH-D72: there was no effect with the low power carrier but the high power one brought a noticeable background hiss on the signal. The TM-D710 performed close to the TH-205E. There was barely any noticeable effect from the high power in-band carrier.

I think the results of these tests, crude though they are, are interesting. The bigger the radio, the more likely it is to have a receiver able to handle adjacent strong signals. Paying lots of money for the latest technology is no guarantee of getting a better receiver. In fact, just the opposite. An ex-commercial handheld or a ham band one from the days when wide band receive coverage was not considered important will work better than the latest marvels.

Were it not that I find the full APRS functionality of the VX-8GR and TH-D72 useful, I’d be tempted to sell both those radios and just use a dumb tracker plugged into the mic socket of one of the others tuned to 144.800. Either I use the VX-8GR for APRS only and carry another radio for making contacts or I must try harder to love the TH-D72. Decisions, decisions. But at least I now have a bit more information to base them on.

Ever since my outing on to Ling Fell yesterday I have been bugged by not knowing for sure whether the problems I experienced with the VX-8GR were really caused by receiver overload or blocking. I like the construction and features of the Yaesu. But a radio that makes you miss some of the contacts you have laboriously sweated up a summit to make is about as much use as a chocolate teapot. I wondered if I could devise a test to give me an idea of the relative strengths of the different 2m radios. I did, and the candidates are lined up in order of merit below, the worst on the left and the best on the right.

The test methodology was crude. I connected each radio to my dual band vertical and tuned in a weakish station: the GB3AS repeater on 145.600MHz, which is normally an S3 signal – fully readable but with some background noise on the audio. I then transmitted a carrier on 144.025MHz using another radio on a helical antenna a few metres from the vertical. I tried two power levels of the interfering signal, 3.5W (“high power”) and 0.5W (“low power”), these being the available power levels of the test radio. This 8dB difference in the interfering signal level had different effects on the ability to receive the repeater signal.

I am well aware of the limitations of the test I carried out. In real life SOTA or WOTA use a radio may be subjected to strong in-band signals from activators on other summits but they will not be as strong as the signal from a radio a few metres away from the antenna. A radio is likely to be subjected to strong signals from outside the amateur band such as pagers and other commercial signals, which the bandpass filters in modern radios due to the marketing-driven necessity of providing wideband receive coverage will do nothing to attenuate. Many strong signals may mix together to cause intermodulation effects if not blocking. However, a receiver that can handle a strong in-band interfering signal is likely also to be better at coping with many strong signals being received over a range of frequencies. So I think my test results have some validity.

Beginning with the worst receiver, the results are as follows.

• VX-8GR. This receiver was the worst affected by blocking. Noticeable desensing of the repeater signal occurred when the in-band carrier was on low power, while a weak noisy “4 by 1” signal was killed completely. The repeater signal cut out completely when the in-band carrier was keyed on high power. Engaging the RX ATT (menu option 1) caused the repeater signal to drop below the squelch threshold so it was not much help though it did reduce the desensing effect on stronger signals.
• JMT-228. The VX-8 was slightly worse than the Jin Ma Tong JT-228, a £30 Chinese handheld bought on eBay. In fairness, the JT-228 is slightly less sensitive than the Japanese ham radios (judging by the signal to noise ratio on weak signals) which may have helped it a bit. Desensing was noticed when the in-band carrier was on low power, and the repeater signal cut out when it was on high power.
• TH-D72. The Kenwood TH-D72 may only be third worst (or third best) but in fact it was a whole lot better. No detectable desensing occurred when the in-band carrier was on low power. Some desensing occurred, in the form of a drop in S-meter reading and increased noise on the audio, when the carrier was on high power.
• GP-300. Excellent performance was given by the Motorola GP-300. No desensing was noticed when the in-band carrier was on low power. There was a very slight but hardly noticeable increase in background noise level when the carrier was keyed on high power.
• TH-205E. I bought this old boat anchor as a “spares or repair” radio for £6 on eBay for the fun of seeing if I could get it going. With the high capacity battery pack it is about the weight and bulk of an FT-817 and not something I would particularly want to haul up a summit. But no desensing of the repeater signal was observed even when the in-band carrier was keyed on high power, making this the best performing receiver of all.

Out of interest I also carried out the test on my FT-817ND and the Kenwood TM-D710 I use as my 2m base station. The FT-817ND was slightly better than the TH-D72: there was no effect with the low power carrier but the high power one brought a noticeable background hiss on the signal. The TM-D710 performed close to the TH-205E. There was barely any noticeable effect from the high power in-band carrier.

I think the results of these tests, crude though they are, are interesting. The bigger the radio, the more likely it is to have a receiver able to handle adjacent strong signals. Paying lots of money for the latest technology is no guarantee of getting a better receiver. In fact, just the opposite. An ex-commercial handheld or a ham band one from the days when wide band receive coverage was not considered important will work better than the latest marvels.

Were it not that I find the full APRS functionality of the VX-8GR and TH-D72 useful, I’d be tempted to sell both those radios and just use a dumb tracker plugged into the mic socket of one of the others tuned to 144.800. Either I use the VX-8GR for APRS only and carry another radio for making contacts or I must try harder to love the TH-D72. Decisions, decisions. But at least I now have a bit more information to base them on.

Talk about the trip of a lifetime! This from their new website launched today:

Jan Mayen Island is a volcanic island in the Arctic Ocean and part of the Kingdom of Norway. It is 55 km (34 miles) long (southwest-northeast) and 373 km2 (144 mi2) in area, partly covered by glaciers (an area of 114.2 km2 or 44.1 mi2 around the Beerenberg). It has two parts: larger northeast Nord-Jan and smaller Sør-Jan, linked by an isthmus 2.5 km (1.6 mi) wide. It lies 600 km (about 400 mi) northeast of Iceland, 500 km (about 300 mi) east of central Greenland and 1,000 km (about 600 mi) west of the North Cape, Norway.

Jan Mayen island is not placed at the top of the 100 Most Wanted DXCC list, but it’s still very wanted in some areas and modes – especially West Coast of the USA, Japan, Oceania, Africa.

After a deep analysis of specific areas vs. modes, we decided to focus on CW and RTTY as our primary modes during JX7VPA.

Since our path towards Africa (where, according to feedback we received, it is still very wanted) will be a bit more difficult due to island’s terrain, we will try to test long path conditions if short path fails.

First day of our activity will be used to check openings toward different areas as conditions we will find at the island may be a big surprise due to polar day period 24/7.

The biggest threat we must face while at Jan Mayen is auroral activity. Since the island is in range of often Au oval’s activity, any increase of A/K indexes may result in deep RF blackouts. Please keep that in mind if our signals disappear from bands suddenly.

Take a moment to check out their website and of you’re a CW or RTTY op, mark your calendar for early July.

Welcome to Handiham World!

And welcome to our special occasional computers-drive-me-crazy edition! Since the personal computer has become such a mainstay in the ham shack, every so often we devote an edition to the blessings and curses these machines visit upon us, and this is that edition.

If you are anything like the typical computer user, you use your computer to do a variety of plain vanilla tasks like web browsing and email. These functions are so mainstream that even grandma and grandpa have become comfortable with them. I know from my experience with amateur radio and amateur radio operators that most of us will go way beyond asking our computers to do those basic things. The typical ham shack is full of equipment that is just begging to play “tag, you’re it” with your computer. There is a specialty software for everything from antenna modeling to rig control, and of course VoIP software like EchoLink. Ham radio operators are often interested in other activities like astronomy, photography, aviation… The list seems to be just about endless. Personal computers can host software applications to make all of those other hobby activities even more fun. With all of these different applications installed on the ham shack computer there is potential for conflicts and – dare we say it – computer problems.

Who among us hasn’t had their personal computer drive them crazy on a semi-regular basis? Whether it is just one application that simply refuses to work even though it worked perfectly the day before or the whole computer being overtaken by malware or perhaps some kind of hardware failure, we have all experienced the frustration of dealing with this machine that has become pretty much essential in our daily activities. Why do we keep it around? Well, because it’s so doggone handy! I know I would hate to go back to the bad old days of typing on a typewriter. I’ve always been a terrible typist and make oodles of mistakes that used to require gallons of white correction fluid. When I type something on a typewriter, it is more efficient to use a paint roller to apply the correction fluid to the page than that little brush that comes in each bottle of “Type White”. In fact, I am typing this using voice input computing, Dragon NaturallySpeaking to be specific. I know my blind friends would hate to go back to the days before personal computers and modern screen readers opened up so many pathways to accessibility. And in the ham shack my radios are controlled by software, Ham Radio Deluxe, and I’m afraid I’ve gotten pretty spoiled with how easy this software makes keeping my amateur radio logbook up-to-date. Although the computer may be a pain in the posterior more often than I think it should be, I would never go back to the bad old days of pre-computer ham radio.

So today let’s take a look at some ongoing issues with computers in the ham shack and computers in general as well as some new stuff that has been suggested to us by Handiham members.

For Handiham World, I’m…

Pat Tice
[email protected]

Welcome to Handiham World!

And welcome to our special occasional computers-drive-me-crazy edition! Since the personal computer has become such a mainstay in the ham shack, every so often we devote an edition to the blessings and curses these machines visit upon us, and this is that edition.

If you are anything like the typical computer user, you use your computer to do a variety of plain vanilla tasks like web browsing and email. These functions are so mainstream that even grandma and grandpa have become comfortable with them. I know from my experience with amateur radio and amateur radio operators that most of us will go way beyond asking our computers to do those basic things. The typical ham shack is full of equipment that is just begging to play “tag, you’re it” with your computer. There is a specialty software for everything from antenna modeling to rig control, and of course VoIP software like EchoLink. Ham radio operators are often interested in other activities like astronomy, photography, aviation… The list seems to be just about endless. Personal computers can host software applications to make all of those other hobby activities even more fun. With all of these different applications installed on the ham shack computer there is potential for conflicts and – dare we say it – computer problems.

Who among us hasn’t had their personal computer drive them crazy on a semi-regular basis? Whether it is just one application that simply refuses to work even though it worked perfectly the day before or the whole computer being overtaken by malware or perhaps some kind of hardware failure, we have all experienced the frustration of dealing with this machine that has become pretty much essential in our daily activities. Why do we keep it around? Well, because it’s so doggone handy! I know I would hate to go back to the bad old days of typing on a typewriter. I’ve always been a terrible typist and make oodles of mistakes that used to require gallons of white correction fluid. When I type something on a typewriter, it is more efficient to use a paint roller to apply the correction fluid to the page than that little brush that comes in each bottle of “Type White”. In fact, I am typing this using voice input computing, Dragon NaturallySpeaking to be specific. I know my blind friends would hate to go back to the days before personal computers and modern screen readers opened up so many pathways to accessibility. And in the ham shack my radios are controlled by software, Ham Radio Deluxe, and I’m afraid I’ve gotten pretty spoiled with how easy this software makes keeping my amateur radio logbook up-to-date. Although the computer may be a pain in the posterior more often than I think it should be, I would never go back to the bad old days of pre-computer ham radio.

So today let’s take a look at some ongoing issues with computers in the ham shack and computers in general as well as some new stuff that has been suggested to us by Handiham members.

For Handiham World, I’m…

Pat Tice [email protected]

This afternoon I went for a stroll up Ling Fell, LDW-205. It was a fine afternoon and I wanted a bit of exercise. I took the VX-8GR so I could test the new QRU feature of Lynn KJ4ERJ’s APRSISCE/32 software that allows an APRS user to receive information about nearby objects on request. I have created a QRU server for Wainwright summits so that an APRS user in the fells could receive information about the nearest summits, to aid identification or navigation.

I put a 2m helical antenna on the rucksack support for the walk up, so the VX-8GR could send my position. The other channel was monitoring 145.500MHz (S20) the FM calling channel. As I gained height I started to hear some loud bursts of interference, a combination of a whine and a buzz, on S20. When I got to the top I switched antennas to the RH-770 dual band telescopic. My first call was answered by Colin, 2E0XSD. His signal was moving the meter on the VX-8GR to an S3 or 4 but there was intermittently a lot of crackly interference over his audio. I tried engaging the RX Attenuator option in the VX-8GR menu and it did seem to improve things a bit, but not completely.

A bit later, when I was testing the QRU server, I could hear the APRS packets coming back from my gateway (which is line of sight from Ling Fell, just behind me in the distance in the picture) but they sounded distorted and the VX-8GR didn’t decode them.

I wondered if there was a fault with the cable to the rucksack mount so I put the antenna directly on the radio. My next call was answered by Geoff G4WHA from his car in the car park in Penrith. He was 5 by 1 but his signal was cutting out intermittently. I got the feeling the problem wasn’t Geoff’s, but was my receiver cutting out due to overload from some nearby transmitter. There is a commercial mast a couple of miles away on the other side of the valley, though I have no idea what is on it.

I am starting to get a feeling that the receiver in the VX-8GR is not much good on summits when connected to a decent antenna. I first noticed odd things with the original VX-8R I had when I tried it out with a SOTA Beams MFD. There have also been several occasions when other people using VX-8 series rigs on summits have failed to hear me, even though I could hear them clearly and in some cases was running much more power than they were. This is quite disappointing. I really like the VX-8GR and much prefer it over the Kenwood TH-D72 which I have been thinking about selling. But perhaps it would be better to keep the Kenwood.

I wish that I had the test equipment to try to compare the strong signal performance of my various hand held radios. HF radios have their receiver performance exhaustively tested and the results of tests by the likes of Sherwood Labs are endlessly debated on various reflectors despite the fact that the only difference it is likely to make is whether you can copy a very weak station right next door to an extremely strong one. But the reviews of VHF radios focus only on matters like the ease of use of the menu system, how many memories it has or how the scanning works.

I think the receive performance of VHF/UHF hand helds is just as important as for HF receivers. If a receiver can’t cope on a hilltop on the middle of nowhere how will it fare with the signal levels in a busy urban environment? Heck, you might be missing vital emcomms messages and not know it! It’s about time the ham radio magazines started publishing blocking dynamic range and cross-mod figures for hand held radios.