AmateurRadio.com

I’m finally eligible to claim one of my own WOTA certificates! This morning I made a contact with Phil G4OBK/P on Souther Fell and thereby completed working all of Wainwright’s Northern Fells.

Phil had preannounced his intention to visit Souther Fell on the WOTA website, which was the last one I needed. This fell is blocked by higher mountains so I can’t work it from home – I would have to get to a good vantage point. I could have driven to a suitable spot, parked and waited for Phil to appear but I decided to make the contact from a summit. The weather forecast was for rain, however, not the kind of conditions I normally choose for an activation. Out of the rucksack came the antenna mount (so I could use the waterproof rucksack cover) and the APRS radios (too expensive to risk getting wet.) The rig for the day was the Motorola GP300 with the base loaded Nagoya half wave telescopic.

The weather lived up to the forecast. By the time I reached the summit my boots had taken on water from the numerous puddles and long wet grass I had to traverse to reach it. My Goretex waterproof was letting in the rain, too. Only the inside of my rucksack remained dry. The views from this summit can be spectacular, but today was no day for a camera. So no photos. Instead, I’ll link to a page that has some pictures of what I could have seen on a better day.

I had to make several calls before I could raise anyone. Finally Malcolm M0XAT heard me. Next the Penrith duo, G0TDM and G4WHA, and then Colin G4UXH and Sue G1OHH from “down south” who were both at good signal strength. I then had a bit of a wait before Phil arrived on summit and began to call. I passed the time trying to wring the water out of my socks.

Mission accomplished I headed back down to the car, home and a hot bath. The radio and antenna are now in the hot water tank cupboard drying out. My boots will probably take a bit longer.

I’m finally eligible to claim one of my own WOTA certificates! This morning I made a contact with Phil G4OBK/P on Souther Fell and thereby completed working all of Wainwright’s Northern Fells.

Phil had preannounced his intention to visit Souther Fell on the WOTA website, which was the last one I needed. This fell is blocked by higher mountains so I can’t work it from home – I would have to get to a good vantage point. I could have driven to a suitable spot, parked and waited for Phil to appear but I decided to make the contact from a summit. The weather forecast was for rain, however, not the kind of conditions I normally choose for an activation. Out of the rucksack came the antenna mount (so I could use the waterproof rucksack cover) and the APRS radios (too expensive to risk getting wet.) The rig for the day was the Motorola GP300 with the base loaded Nagoya half wave telescopic.

The weather lived up to the forecast. By the time I reached the summit my boots had taken on water from the numerous puddles and long wet grass I had to traverse to reach it. My Goretex waterproof was letting in the rain, too. Only the inside of my rucksack remained dry. The views from this summit can be spectacular, but today was no day for a camera. So no photos. Instead, I’ll link to a page that has some pictures of what I could have seen on a better day.

I had to make several calls before I could raise anyone. Finally Malcolm M0XAT heard me. Next the Penrith duo, G0TDM and G4WHA, and then Colin G4UXH and Sue G1OHH from “down south” who were both at good signal strength. I then had a bit of a wait before Phil arrived on summit and began to call. I passed the time trying to wring the water out of my socks.

Mission accomplished I headed back down to the car, home and a hot bath. The radio and antenna are now in the hot water tank cupboard drying out. My boots will probably take a bit longer.

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.

Yesterday I was out hiking round the back of Skiddaw in Wainwright’s Northern Fells to activate Great Sca Fell (LDW-114) and Brae Fell (LDW-134). One reason for being out and about in that area was that Phil G4OBK was planning to activate Great Calva (LDW-095) which is one of the three summits I need to complete the Northern Fells as a chaser. I’d have been less keen if the weather had been miserable, but Thursday was a glorious day, sunny but not too hot and without the breeze that can often make it icy cold on the tops even when it is warm in the valleys.

It is a long, steady plod up from Longlands and I reached the summit of Great Sca Fell around 12:30. I put up the WOTA Pole and then sat down to eat my lunch. To raise the height of the antenna I used my walking pole for the bottom section. This didn’t give me as much extra height as I’d hoped as the inner sections of the telescopic pole slid up inside the PVC tubing so I had to collapse it and just use the thickest, topmost section.

I connected the VX-8GR to the antenna to beacon my position on APRS while I ate the lunch Olga had made me. I tuned around whilst I was eating and heard a couple of distant stations. I observed their signals being desensitized intermittently. Clearly the VX-8GR receiver is not up to being connected to a good antenna in a good location.

After lunch I connected the Motorola GP300 – which has a much more robust receiver – to the antenna and began calling CQ WOTA. I worked 11 stations in all from Great Sca Fell, but they were all from the northen area as signals to the south were blocked by the great bulk of Skiddaw and Blencathra. I waited for Phil G4OBK to arrive on his first summit of the day, Bakestall, so we could have a summit-to-summit contact. I then called upon Mark MM1MPB and Colin 2E0XSD to help with my second objective of the day, which was to do some tests to see how much difference the WOTA Pole made to my signal compared to other antennas.

First I compared the signal between the WOTA Pole (which is a Slim Jim made of 300 ohm ribbon cable inside some PVC electrical conduit) and the 5/8 wave telescopic Black Whip antenna from jeepbangkok on eBay. I’d been pretty impressed with the 5/8 telescopic on previous activations but the reports from Mark and Colin suggested that the WOTA Pole was a couple of S-points better.

Unfortunately while extending the telescopic antenna to make the test I broke it! That’s the end of that, which is a pity because I’m sure there will be circumstances – such as on busy summits or rocky ones where there is no earth to drive the guy pegs in – where the telescopic would still be useful.

For an additional test I tried an 8 inch long single band helical “rubber duck” which I’d previously established to be comparable to a quarter wave whip and a noticeable improvement over the stock dual band antenna that comes with Japanese handhelds. Colin couldn’t hear me on the helical at all, while Mark’s verdict on my signal was “awful.” So the WOTA Pole is very definitely worth the trouble of erecting it and enables me to give points to stations that would not otherwise be able to hear me.

I packed everything up and made my way over to Brae Fell which was half way back to the car by another route. I set up the antenna and finished the rest of my coffee. A lone skylark, perhaps the first of the year, circled calling overhead. I began calling on the radio. Again there were plenty of takers. I worked 12 stations in all including another summit to summit with G4OBK/P on Great Calva.

So a successful day out (apart from breaking an antenna.) I just need to work someone on Mungrisdale Common and Souther Fell to complete the Northern Fells. They have been activated before: unfortunately they are not workable from home due to being of only moderate height and on the other side of Skiddaw. As they are probably the two most boring hills in the entire Lake District they are not often visited so I may have a bit of a wait until I can claim my Wainwrights On The Air Northern Fells chaser certificate.

Yesterday was one of those clear, blue, sunny, still, cold days that make you think it would be a criminal waste to stay inside. I decided to try another Wainwrights On The Air activation using my WOTA Pole, which had been rebuilt since Sunday’s disaster. My intention this time was to visit the summit of Knott, LDW-082, followed by nearby Great Calva, LDW-095. I took the VX-8GR for APRS but this time I also took the Motorola GP-300 to use for the activation which I hoped would avoid the receiver overload problems experienced with the Yaesu.

The weather may have been bright, but I was not. Sometimes I seem to get periods of a few days when although physically I may be awake, mentally I am not. Fortunately I hadn’t driven far before I realized I had not put walking boots in the car, so a complete disaster was averted. That wasn’t the only silly mistake I was to make, though.

I parked at the head of Mosedale and started walking up the Cumbria Way path. I approached the structure you can see from the starting point, which turned out to be a large garden shed! The path seemed to be taking me near to High Pike so I thought I would make that my destination and visit Knott on the way back.

As I approached the “shed” I heard people making contacts with another hilltopper, Gordon G0EWN/P on Grey Knotts. I took the VX-8GR from the rucksack and made several calls using the helical whip as he completed each contact but he always replied to someone else. After ten minutes of standing around I decided to shoulder the rucksack again and continue climbing while holding the radio. I called several times when Gordon listened for “any more calls” but he was not hearing me. I don’t know why that was – another case of a radio front end being overloaded by high signal levels on the fell-top perhaps?

I reached a grassy summit topped by a tiny cairn and checked my position and realized that I was further from High Pike than I thought. I also then realized that I didn’t have my walking stick! I must have left it by the “shed” when I stopped to try to work Gordon! I turned round and went back. I retrieved my stick, but having wasted half an hour I decided to abandon High Pike and carry on to Knott instead.

I arrived at Knott still in sunshine with clear blue sky, the distant summits slowly disappearing in the haze. Although it was calm enough to try using the WOTA Pole supported in my rucksack I decided to use the guying kit from the MFD that I’d brought with me in case of windy conditions to avoid the trouble I’d had on Sunday. That cost the antenna some height, but on the plus side it allowed me to operate sitting down which I was glad of as I’d been climbing for over 2 hours by this point. Whilst I ate my lunch I connected the VX-8GR to the WOTA Pole and it was picking up APRS packet bursts from as far afield as Norway and Holland. VHF conditions were obviously up.

When I finished my lunch I connected the GP-300 to the antenna. This was when I discovered I’d brought the wrong speaker-mic. One of the hazards of owning too many hand-held rados I suppose! It was not a major problem of course, as I could use the radio without it. I made several contacts from the summit of Knott the most distant of which was G6ODU in Ormskirk, Lancashire, not a bad haul from the North Lakes.

The wind was so calm my Olympus voice recorder logging device was able to make a high fidelity recording of the activation. In case anyone is interested to hear what it sounds like at the sharp end of a WOTA activation here is a recording of about 8 minutes of activity. The loud, punchy audio from the Motorola GP-300 really helps so you can hear both sides of the contact equally well. Some of the quality has been lost compressing it down to an MP3 file of reasonable length but it’s still almost like being there!

I would have liked to stay on the hill longer to see what else I could work, or even move on to Great Calva to activate that, but a thick bank of mist was approaching and I didn’t want to be up there in mist. There are few clear paths on these infrequently walked grassy summits and without any landmarks to aim for it would be easy to get lost. Even though the visibility was clear I still went the wrong way off the fell and hit the Mosedale to Skiddaw House path much closer to Skiddaw House than to Mosedale. That cost me an extra 3km or so of walking to reach the car, by which time the mist had arrived and the sky was a grey murk.

This was long walk for only one summit activated. I could have made more if I’d had my wits about me and things had gone according to plan. But on a day like this it’s good to be out however many summits you activate!

Sunday was a fine but cold autumn day and Olga and I went for a walk near Loweswater. In my rucksack I took the Motorola GP300 and the FoxTrak APRS tracker. This is a somewhat more bulky arrangement than using the VX-8GR, however this hobby has for me always been more about providing a reason to build and tinker about with stuff than using the latest, most efficient technology and using this home-built tracker with a radio I bought for £1 at a rally is just somehow more fun than using Yaesu’s latest gadget.

I had obtained a cable for the Motorola with the correct two-pin plug to make up an interface. I cut the tip off the 3.5mm jack so that inserting the plug did not cut off the speaker and I programmed a channel on the radio with 144.800 as the transmit frequency and 145.500 as the receive frequency. This meant that I could hear anyone calling CQ during the periods between transmitting position beacons. The downside is that the FoxTrak cannot tell if the APRS frequency is clear before transmitting. But many dumb trackers do that already because they don’t have a receiver. In any case, the APRS activity level here is so low that the chances of a collision occurring are about the same as winning the lottery.

Although the path we walked along was quite high, this was not a very good location for radio. Only one position beacon was received by a gateway and I made just one voice contact – with Phil M0AYB/P activating the summit of Blencathra for WOTA. (Phil later went on to activate Mungrisdale Common which completed activations of all of Wainwright’s Northern Fells. I’m doubly sorry to have missed contacting him there, but congratulations Phil on the achievement.)

Our walk took us down through the woods to the lake shore and then back to the car. The autumn colours were wonderful – my pictures don’t really do justice to them. I expect most of the leaves have now gone. Last night there was a gale and this morning through the overcast we could see wet snow on the mountains down to quite a low altitude. I doubt that there will be many more opportunities for a walk like this before the end of the year.