Monday, 27 March 2017
On Saturday, conditions on VHF and UHF were really good. Hearing a lot of activity from Ireland, and even signals from as near as Blackpool were a lot better than normal.
The video is just my radio scanning round 2m and 70cm, showing what kind of signals I was getting from some DMR repeaters, the best propagation was to GB7UL on 439.525 at Carrickfergus.
On 145MHz, GB3MP on 145.750 was a bit stronger than normal, you can hear some interference on all the VHF signals, like a clicking noise. This happens at certain times of day, and is on top of the already high noise level - if I turned the squelch down on the FT-7900, it would be showing S3 of noise right across the 144MHz amateur band.
I could hear a repeater on 439.100 which had an Echolink conversation on it, that isn't a repeater frequency used anywhere in the UK for analogue or digital, and the only mention I could find online was a repeater in Germany. I couldn't find any CTCSS tone when scanning for one either.
Friday, 17 March 2017
Here are UHF handhelds for under £2 each
Friday, 3 March 2017
DSD+ was trying to decode the DMR but there were so many errors it could not even get the correct colour code on a strong signal. Definitely the transformers causing the problem.
I checked their frequency response by looping the UA-25's output back to the input and playing some test tones through it, then comparing with a straight through cable.
The table below shows the insertion loss at each frequency compared to a straight through cable.
But, unlike a lot of other wearables, it uses a non-rechargable lithium cell (CR1632 - not a very common size, couldn't find any in Poundland so ordered some spares online) which can last up to 12 months. I've not had to change mine in the 9 months I've had it. It's waterproof and I've never needed to take it off.
As well as steps, it can measure heart rate (with a chest strap which I've never tried) and sleep (by tracking movement, not by brain waves or anything as clever). I usually keep an eye on steps and distance throughout the day, walking a bit more in my lunch break since I've got it.
At the gym it's sort of useful, some of my gym activity adds to the step and distance count but it's no use on the bike and might not be that accurate on treadmill and cross trainer as the movement isn't natural walking or running. The daily step target varies depending on how well I've done over the last few days, it's usually over 10000 unless I've spent a few days off work doing nothing.
Here are a few screenshots from the Android app, Garmin Connect. I find that to sync the device, I need to start the app, kill it in the task manager and then start it again before pressing the sync button. The app also needs internet access to work at all, it won't even sync offline as all the data is stored on Garmin's servers.
Monday, 27 February 2017
See this video for very long range experiment using LoRa modules. LoRa is a spread spectrum (125KHz bandwidth) data mode which can be received at very low signal levels, and its main use will be for the Internet Of Things - smart meters and other stuff which only needs to transfer a small amount of data. This is all done in licence free bands that are normally used for low power data such as remote controls.
There is also The Things Network, connecting LoRa gateways around the world which anyone can access (it's a bit like the amateur radio APRS gateway system but for LoRa devices). There are already a few set up in the Liverpool, Manchester and Lancaster area.
The YouTube channel above has instructions on how to build both a node and a gateway for LoRa.
You can get LoRa modules for the 433(in the amateur band but low power devices are used here), 868(main band in Europe) and 915MHz (USA) bands.
It's interesting to see that there's so much experimenting with radio going on outside of the usual amateur radio bands and organisations. To me, anything that could possibly get more than a few hundred metres is worth trying (further than your average indoor Wi-Fi access point).
Monday, 6 February 2017
And while I'm taking photos in the kitchen, here's Friday's tea
One button, one LED. Press the button once at 2 seconds past an even minute to begin the first transmission. I use the Clock Sync app on my phone to get an accurate time via the internet.
I've no permanent HF antennas at home so I tried it in the car, with a Watson Multi Ranger antenna. The mag mount is a bit small for the HF bands but I found it worked OK on 14MHz, with 20 reports in the first hour of use. I powered it from a TP-Link power bank, and at 180mA on transmit and under 50mA waiting, it will last for days on that. My USB power monitor won't measure below 50mA so read zero except when transmitting.
At that low power, most SWR meters won't let you calibrate to full scale, but as long as they have a separate reverse power reading, you can see when the SWR is OK (3:1 would be 25% reflected power, 2:1 9% etc.).
The next time I tried it in the car on 14MHz, I got 2 reports from the USA.
Compared to the usual 5 watts I'd been using for years on WSPR when I had a proper HF radio, 200mW (14dB down) needs a bit more effort - 5 watts will work into just about anything with WSPR, especially with an auto tuner. At 200mW an auto tuner might not even start to tune on transmit. I think the mobile whip is just as efficient as a random length of wire.
On Saturday I made my first SOTA chaser contact on DMR (or any digital voice mode). I've made QSOs from summits on both D-Star and DMR before though. When I was scanning round, I heard some activity on 438.6125, so quickly changed over to the DMR radio and spoke to 2W0SEY/P on Moel Famau (G/NW-044).
For tea on Saturday we went out to One Restaurant in Barrow. The last time I'd been there was 3 years ago for my birthday and tried The Challenge of eating a massive burger, hotdog and fries in 45 minutes (and failed). This time I settled for the normal menu
Wednesday, 1 February 2017
I've had the RF Explorer for over 5 years but only just tried the PC software for it.
930 - 935MHz: O2 (3G) base stations
390 - 395MHz: Airwave TETRA base stations
950 - 955 MHz: Vodafone (2G) base stations - a lot lower than O2's sites here
I've ordered a WSPRlite to get myself back on HF, if only at very low power.
Monday, 30 January 2017
Post title randomly generated
145.500 activity from this weekend recorded at home -
Saturday 28th January
CQ call early on but couldn't get callsign properly - possibly M0CQE?
GW7HEM/P - Foel Fenlli SOTA GW/NW-051
GW4TJC/P on Foel Fennli and later on Moel Famau GW/NW-044
2E0LBI/P on Birkrigg Common
Sunday 29th January
2E0KUK/P Great Whernside SOTA G/NP-008
G4RQJ/P Gummer's How SOTA G/LD-050
Monday, 23 January 2017
All I had to use were two handhelds, both with their own antennas. As one of them had DMR, I tried putting some calls out on 438.6125 and posting a spot on the Sotawatch web page. This was a weekday afternoon so not the best time for any activity and got a total of 0 DMR contacts.
On 70cm I got a few more contacts and there was a lot less interference, but it wasn't 100% noise free - the strongest UHF signal up there would be Airwave, with no UHF business users there any more. I wonder how that would have affected DMR - it's easier to tell on FM if there is interference because you can hear it, with digital voice there would be drop outs or just silence.
I parked at around SD524021 on the road north of the summit which is just below the activation area (unlike every other time I've been up there) and walked past the buildings before crossing the fields. As it was an unexpected activation, the white trainers I had on weren't the most suitable footwear for crossing the muddy fields.
Saturday 21st January
Didn't do the usual 145.500 recording, instead I left the FT-7900 scanning 4 digital voice channels
(.5875 is the most popular DMR frequency near me)
with the squelch turned down and decoding the 9k6 packet output with DSD+. This checked each channel for about 5 seconds before moving on.
Total activity during the daytime was one station - 2E0LBI
Sunday 22nd January
Recorded 145.500 as normal.
CQ calls heard from
G6PJZ/P CQ SOTA. No summit given but was spotted from G/NP-022 Calf Top so probably there.
M0HQO/P CQ SOTA. I wish people would say the summit name on the calling frequency and save me having to look it up! Spotted on G/NP-008 Great Whernside.
G4RQJ/P CQ SOTA from G/LD-052 Hutton Roof Crags.
G7PAJ/M calling from Kirkstone Pass. Didn't seem to have any replies.
Someone else mobile might have called CQ in the afternoon but their audio was very low, someone did reply to them though.
Also been using the Last Heard feature of the Retevis/Tytera modified firmware and leaving the DMR radio scanning simplex channels.
Sunday, 15 January 2017
Saturday 14th wasn't much better, between 9am and about 3:30pm there was one single station - G6ZET in the Lancaster area.
Not long ago I was in the local Poundland and spotted some rechargeable USB power banks.
Wednesday, 11 January 2017
Monday, 9 January 2017
CQ calls heard on 145.500, at home, Sunday 8/1/17 (the whole day apart from when I was using the radio):
GM3VMB - Annan
The area round Gretna and Annan is a good VHF path for me, over just the highest points of the Lake District fells.
M6VMS/P on SOTA G/LD-018 Stony Cove Pike
2E0DVV - Ulverston
G8INU - Blackpool area
G8BEK - Burnley
I also do quite well towards Burnley, Walney Island being as far back as possible from the Forest Of Bowland probably helps.
Saturday, 7 January 2017
- M0BKQ/P on Whernside (SOTA G/NP-004)
- M0KCB/P - no summit references given but the first call was for both SOTA and WOTA so looking at the WOTA website, shows an activation of Gummers How (LDO-067) in the morning. A later call was "CQ WOTA" only, so probably Staveley Fell, (LDO-084).
- G8INU (Blackpool area)
- Some stations calling others
- 2E0MVH calling through GB3MP 145.750 - spoke to Sean on the repeater (it's a while since I've been on MP!)
I spoke to M0BKQ/P while I was out in the car this morning, first SOTA chaser QSO and first voice QSO of 2017.
If you do put a call out on 145.500 at the weekend, even if you don't get any replies, there's a good chance I'll have heard you if you're within VHF range. Weekdays I usually run the APRS gateway instead. I'm going to try and post as many reception reports as I can from the calling channel, if I'm recording or not able to get back to someone.
Friday, 6 January 2017
They are supposed to be 500 Megabit but as they only have 100 Meg ethernet to connect to anything, that's a meaningless figure, even if they could manage that in ideal conditions. Anyway I set them up by doing the usual button push and they worked as well as the Wi-Fi from router to the bridge I use to connect my main PC wirelessly, with our FTTC broadband.