I just wired up my MFJ-1786 magnetic loop, which hasn't been used for years. Unfortunately, it looked like the loop controller had gone U/S.
Friday, 18 March 2022
Repairing a MFJ-1786 magnetic loop
I just wired up my MFJ-1786 magnetic loop, which hasn't been used for years. Unfortunately, it looked like the loop controller had gone U/S.
Thursday, 18 February 2021
HF propagation charts updated for 2021
I've now updated my propagation prediction charts for 2021 with the predicted smoothed sunspot numbers from NOAA/NASA.
So that's a chart for every hour, for every band and for every month, or more than 2,300 charts in total! The process is fairly automated, but it still fairly tedious and takes about a day to do.
The charts are useful as a quick guide to what parts of the world may be workable and which aren't. If you want more accurate charts then the ITURHFPROP-based predtest.uk or the VOACAP-based voacap.com websites are better.
I may need to update them as the year progresses as we get a better idea of how Solar Cycle 25 pans out. At the moment it isn't looking too good. December 2020 saw a sprinkling of SS25 sunspots with a corresponding rise in HF activity. But since January is has been pretty dire really with long periods of no spots
Anyway, to avoid confusion, I have updated form February onwards. This means that January is actually for 2022.
The charts are produced using Hamcap which is a VOACAP-based application and they are for short-path only.
Wednesday, 24 June 2020
VHF propagation video released on YouTube
The video was originally produced for club presentations, but with Covid-19 and the lockdown, it wasn't getting much use.
So if you have never heard what an auroral contact sounds like, for example, now's your chance!
See https://www.youtube.com/watch?v=5Yo4IFn6AAY&t=8s
Steve G0KYA
Chairman, RSGB Propagation Studies Committee
Monday, 30 March 2020
Understanding HF Propagation video released
This presentation was originally produced for use with clubs around the UK and has been used by more than 100.
With the current Covid-19 restrictions in the UK, it looks like club meetings aren't going to be taking place any time soon, so I've released it on YouTube.
I may do some further videos over the next few months - it depends on how long the restrictions last!
See https://www.youtube.com/watch?v=DIAgzpdB67A&t=42s
Steve G0KYA
Monday, 21 October 2019
Range of HF propagation tools launched
We highlighted these at the recent Newark Hamfest.
RSGB has now set up quicklinks to each of the tools, which will make it easier in the GB2RS audio bulletin. These are:
Propquest
Shows real-time critical frequency and MUFs over various path lengths. Excellent tool for HF users.
See www.rsgb.org/propquest
Predtest
Designed by Gwyn G4FKH, calculates the probability of propagation over different paths and for different modes. Includes point-to-point and animated displays.
See www.rsgb.org/predtest
VOACap for RadCom
Shows the probability of propagation to 28 different locations around the world – the same locations used in the RadCom predictions. Can be tweaked for your particular station including mode, gain and power.
See www.rsgb.org/voacap
Proppy for RadCom
Uses the latest ITURHFPPROP tool to calculate the probability of propagation to the same 28 locations used in RadCom.
See www.rsgb.org/proppy
Sunday, 10 March 2019
2019 Commonwealth Contest and QRP
![]() |
My Yaesu FT-817 and Winkey |
This weekend has seen the Commonwealth Contest 2019. I documented my 2018 attempt on the blog, and was keen to give another go this year.
Last year I used my Icom IC-756 Pro 3 wound back to 5W, but this year decided to use my Yaesu FT-817 for a real QRP approach. I bought a USB lead for it this year to give full computer control with N1MM and decided to use my Winkey for full auto CW .
This year I had a slight change to my antennas. Out went the end fed half wave (with 80 loading coil) and in came a 66ft OCFD with the apex at about 8m. Also new was a quarter wave vertical for 20m, erected for the weekend on a 10m fishing pole - more of that later.
The contest ran from 10am, but at 9.30am I was struggling with the computer and interface. Stupid me forgot to turn off the keyer on the FT817 - duh!. Soon we were under way.
The contest got off to slow start with my 5W struggling to break through. Many stations just couldn’t hear me. The quarter wave vertical for 20m turned out to be a noise magnet - almost S8. I decided to abandon it quite quickly.
After an hour I had a few stations in the log - 5B4AGN (Cyprus) and 9H1CG am (Malta), but nothing better. 3B8XF Mauritius (G3TXF) was audible, but I couldn’t break through. Same with ZF2CA Cayman Islands (both 3B8 and ZF were worked last year).
The afternoon saw Canada romping in and I ended up doing an hour at about 10-11pm, clearing up the UK HQ stations.
Sunday started at about 5.30am and a few more Canadians on 40m were cleared up. I then had a big breakthrough - VK4CT on 40m. It wasn’t easy, as they needed three or four repeats on their serial number, but we got there eventually.
So there you go - 34 QSOs in total, which doesn’t sound much, but I didn’t take part for the full 24 hours and it is HARD work with only 5W. Peter M0RYB, a fellow Norfolk Amateur Radio Club member, cleaned up with 70 QSOs in the QRP section. Must find out his secret!
Monday, 4 February 2019
HF propagation charts updated
I had to update them with the latest smoothed sunspot numbers for the next 12 months.
This is a little depressing as after May 2019 the predicted SSN falls to "one" and stays like that for the rest of the year! Sunspot minimum is currently thought to be later this year, but could spill over into 2020.
These charts are meant as a rough guide. Other tools that are available are:
1. The VOACAP RadCom prediction tool - this replicates the locations found in the monthly RSGB publication, but lets you choose your own mode, power and antennas to give more accuracy.
2. The Predtest.uk tool - this tool, developed by Gwyn Williams G4FKH, uses the latest ITURHFPROP prediction engine to let you produce point-to-point or area propagation predictions, again with full control over the input parameters.
3. Propquest - this is a near real-time tool, developed by Jim G3YLA, that shows the critical frequency and extrapolated maximum usable frequencies available over different path lengths. The critical frequency (the frequency at which a radio wave launched vertically stills gets returned to Earth) is derived from ionosonde data, mainly from Chilton and Fairford.
It should be your first port of call to see what conditions are like. In the summer it also has predictions for Sporadic E, courtesy of Jim.
Steve G0KYA
RSGB PSC Chairman