Radials and Counterpoises

This is a talk I gave to Norfolk Amateur Radio Club at its annual Radioactive event. It looks at radials for ground-mounted verticals, including how many do you need and how long should they be. It references the excellent work done by Rudy Severns N6LF. Download the presentations in PDF format (760k). 

HF Propagation - what do the numbers mean?

This was the title of a talk and presentation I gave to the Nuneaton ARC in March 2025.

I have attached a PDF of the PowerPoint presentation, which can be downloaded here.

Without the talk, it may not make total sense, but it at least gives you a flavour of the talk and some insight into what some of the terms mean in HF propagation.

New worldwide 10m beacon list issued

RSGB’s Propagation Studies Committee (PSC) has released a new HF beacon list, with the 10m listings completely revamped.

The old list, which was started by Martin Harrison G3USF (SK), had been added to over the years, but was getting out of date. The only way to make it more accurate was to start again.

Use was made of the Reverse Beacon Network (RBN), which wasn’t available when the list was originally created, plus listeners’ contributions from around the world. 

I started by removing around 60 beacons that had not been heard for some time. Delving deeper it seems that a lot had been taken off the air, the owners had died, or their frequencies had changed.

Using the RBN gave a pretty good indication of what beacons are actually on air, plus help from a list compiled by Gary ZL2IFB filled in some of the gaps.

Beacons that are temporarily off-air have been left in, but marked in black.

While no list will ever be complete as changes take place around the world, I think the list is now far more useable. I’ll endeavour to make changes as and when they are needed.

The new beacon list can be found at:

https://rsgb.org/main/technical/propagation/propagation-beacons/

Help needed with Index Laboratories' QRP+ radio

I need your help! 

But first some background. The Index Laboratories' QRP+ is a 1990's 5W all-band QRP transceiver from the USA. I bought mine at a club sale and it was supposed to be working fine.

But it wasn't! Never mind, we all love a

challenge, don't we?

It seems that the SBL-1 mixer is a common failure point so a replacement was ordered.

The rig comprises four boards, which are stacked and have interconnecting leads.

It is relatively easy to pull apart, and the mixer is on the top board.

After a big desoldering struggle I fitted the new SBL-1 (U5), which brought the receiver back to life. Unfortunately, the TX still didn't work. Back to the drawing board.

The next stage was to replace the final PA transistor, which is on the lowest board. This is a IRF510 (Q9) and I ordered a few off Ebay. I fitted a new one and in tests I found that I could only get about 0.1W out! (on CW) with the gate bias backed off fully anticlockwise. 

Power out should be about 5W.

Anyway, that's as far as I have got. I have attached a link to the circuit diagram and would appreciate any suggestions.

Update

Well, some replacement IRF510s were sourced from the G-QRP club (thanks guys). Apparently, there are some "fake" IRF510s around that don't play well with RF.  After pulling the radio apart (again) and replacing the transistor, it was a little better - about half a Watt output. Anyway, to cut a long story short I have passed the radio to another G-QRP club member and I hope he has more luck than I did! 

Update to UK propagation charts

I'll freely admit that my UK propagation charts had been a bit neglected over the past year. But not any more!

I've now updated them until the end of 2024 with new predicted smoothed sunspot numbers.

I've also fixed a problem with the Kp graphs. They now appear, along with solar X-ray and proton flux graphs. This was because the US Space Weather Prediction Center had stopped the production of the previous Kp chart.

I still recommend both Proppy and VOACAP.com if you want detailed HF forecasts, or if you want to do long-path predictions. But for casual use my charts are fine, and produced using VOACAP.

Leave a comment if you find them useful (or not!).

Incidentally, the SSN charts I used show that the expected solar maximum is the middle of this year.

Preparing the GB2RS propagation report

Attached below is a PDF (14Mb) of the presentation I gave on 15th April 2023 after the RSGB AGM.

It looks at how we prepare the weekly propagation report for the RSGB's GB2RS news report. It contains a lot of useful URLs to sources, data and programs that people might find useful.

Steve G0KYA

Download GB2RS_Propagation.pdf

Ten metres (28MHz) beacon list updated

I've just spent two days updating the RSGB's 28MHz beacon list. I used the reverse beacon network and logged/updated the beacon list accordingly. This takes a lot of time as many of the "spots" are misread and have to be checked individually.

Beacons heard over the last three years are highlighted in red. I'm now happy that it is pretty up-to-date. The RBN has a beacon listing, but it is way out of date - GB3RAL is still listed and that hasn't been on for years.

I think this is the best way as it reflects beacons that are actually transmitting and not just listed. The full beacon list can be found on the propagation section of the RSGB website here: http://rsgb.org/main/files/2023/03/G3USFs-Worldwide-List-of-HF-Beacons.pdf

The actual changes are:

Change of freq/details:

28270.5 PY4MAB  Pocos de CaldasGG68      2W    

28193.1 LU2DT   Mar del Plata  GF12      5W 

28208   WD5GLO  Minco OK       EM15ah    3W 

28281   AG8Y    Middletown OH  EM79TL  7.5W   

28273.8 WI4L    Dalton GA      EM74MS                    

28243   AA1SU   VT             FN34KL    5W   

28209.5 N2UHC   St Paul KS     EM27JM    4W

28203.3 WB9OTX                 EN55      5W             

28280.4 KE4IFI  Lexington SC   EM9JV     7W 

Additions:

28297.9 K4JDR   Raleigh, NC    FM05     10W 

28255.8 WB4NCT  Athens, AL     EM64      5W  

28241.3 WW2BSA  Warren, NJ     FN20OU    7W   

28260.8 IQ8BB   Salerno        JN70JQ      

28178   IQ0GV   Sora           JN61TR    5W    

28236.3 F1ZTS   Rochefort      in97QI   10W     

28266.1 VK4RST  St George QLD  QG41HW   10W

28285.9 AJ4YN   Chesapeake, VA FM16UO    ? ?   

28215   GB3MCB  Cornwall, UK   IO70OJ    ? 

28252.6 WD8INF  Lebanon OH     EM79VK   10W

28258.8 AC5JM   Bartlesville OKEM16FT    ?

28209   N5TIT   Westminster, COEM12PX   10W 

28206.5 N4SO    Grand Bay, AL  EM50tk    6W   

28296.2 VE3IIM  Hanover, ON    EN94LD    4W 

28321.4 IZ1KXQ  La Spezia      JN44WC  0.1W

28230.8 NG7I    Ritzville WA   DN07TC    5W  

28202   WB7EUX  Joseph, OR     DN15JI   10W 

28233.5 K7RA    Seattle, WA    CN87UQ   11W  

28260   KC4QLP  Little Falls NYFN23OB   10W  

28245.3 K0WKT   Black Dia. WA  EN36WT    5W 

28226   K6KWS   Redwood City CA CM87VL  10W 

28240.1 W8EDU   Cleveland, OH  EN91EM   10W

28206.9 N4XRO   Burbank CA     DM04UE    5W 

28276   XE1JAL  Xalapa         EK19MM    5W

28230.3 W2MQO   Grand Island FLEL98dv   10W

73 de Steve G0KYA
Chairman, RSGB Propagation Studies Committee