Monday, 6 February 2017

WSPRlite

My WSPRlite arrived on Friday, from SOTABeams. A 200mW WSPR transmitter, needing no PC or any cables except power (micro USB) and antenna (SMA).



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.).
 No connection at all to the car electrics

 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
 "Alligator Cooler"
 Piri Piri Burger
Chips, Cheese and Gravy
"The Black Hole"


Wednesday, 1 February 2017

RF Explorer

Some channel power measurements (all in a 5MHz bandwidth) on my RF Explorer on the tri-band colinear.
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

955 - 960 MHz: O2 (2G) base stations



452.5 - 457.5 MHz: Various business radio users, mostly continuous trunking data and DMR



 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

Tardily Cohorts

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
GM3VMB

Sunday 29th January
2E0KUK/P Great Whernside SOTA G/NP-008
M5CMO/P
G4RQJ/P Gummer's How SOTA G/LD-050
G6ZET/M

Monday, 23 January 2017

Billinge Hill 2017

Last Wednesday (18th January) I was in the Liverpool area and did an unexpected activation of Billinge Hill (SOTA G/SP-017).
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 145MHz I was using my new Baofeng GT-3. I already knew that this was pretty rubbish on VHF for handling strong signals (at home on my outdoor antenna it was completely overloaded, even though there were no very local VHF transmitters - maybe from FM broadcast or DAB signals then). Billinge Hill is one of the worst places to take any radio that can't handle strong VHF signals, but I did manage to make 2 contacts with stations who would have been S9.



 I almost made a contact with M6BWA/P on Titterstone Clee Hill (SOTA G/WB-004) but I think at both ends we had problems with nearby transmitters and couldn't get more than a few seconds of unbroken reception. Fortunately M0JLA/P was also at the summit there and I spoke to him on 70cm using the other radio. It was like one of those times when it's a big relief that there's a 5th contact from a SOTA summit, because the 4th was a bit suspect - did you really get all their details? was someone using 2 of their own callsigns?


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.




Weekend Calls

Saturday 21st January
Didn't do the usual 145.500 recording, instead I left the FT-7900 scanning 4 digital voice channels
144.5875
144.6125
438.5875
438.6125
(.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

#6 Poundland Power Bank

Not a lot of activity to report on 145.500 so far this week, recorded all Thursday 12th and not a single CQ call from 6am - 10pm.
Saturday 14th wasn't much better, between 9am and about 3:30pm there was one single station - G6ZET in the Lancaster area.
Sunday 15th was slightly better, with G8INU and 2E0DVV calling. But this weekend not a single portable station, must have been the weather.

Not long ago I was in the local Poundland and spotted some rechargeable USB power banks.
Sold as 1200mAh (4.44Wh). When I tested this from full, charging a tablet, it ran for about 70mAh at 5v output then gave up. Tried on a lower current load, with some LEDs and it ran for a total of 170mAh (850mWh). Even with any conversion losses, there was no way the cell inside was 1200mAh (a proper cell of that size would be rated around 2200mAh). 
I'd avoid any power bank of that design, or anything battery based from a pound shop.

Wednesday, 11 January 2017

YouTube Channels

A couple of good YouTube channels I subscribe to, with all kinds of amateur radio/drone/e-bike type stuff

Andy Kirby

Distant Signal