15 Mar 2021

15m FT8 QRP (Monday)

At about 0910z, I turned on my 2.5W to the indoor loop on 15m FT8. No spots yet.

UPDATE 1116z:  13 stations spotted so far on RX. Nobody has yet spotted my QRP on TX.

UPDATE 1500z: 1 station has spotted my QRP FT8 on TX and I have spotted 37 stations on RX. including 2 in South America. Conditions do not seem that great on 15m today.

South African 8m beacon heard in Portugal

Yesterday, the South African 8m beacon was spotted in Portugal. I guess this was TEP. 

Pommes de terre gratin Dauphinoise - NOT amateur radio

This is one of our favourite ways to cook potatoes. Par boiled, cooked with cream and Gruyere cheese. Great cold too.  

We had this yesterday for Mother's Day. Surprisingly, there is still some left.

Sunspots - Monday March 15th 2021

Solar flux is 78 and the SSN 24.  A=24 and K=2.

14 Mar 2021

No radio today

Today, I have not been on the radio on any band. Usually I go on an HF band in the day and 2m FT8 in the evening. 

10m simple (not necessarily single) sideband transceiver

10m is coming back to life. 

At any point in the solar cycle it can be good for Es contacts (in the Es seasons especially) with low power and simple antennas. This autumn we could well see some real F2 DX more commonly on 10m.

One of my aims in the past was to design a very simple rig for 10m sideband that almost anybody could build. Sadly, my health got in the way and even this is probably beyond me now. Others may well have better ideas. All I want is someone to have a go. 

I can see a simple 10m kit in my mind that could be built at really low cost on a single PCB with a simple case. All this to allow everyone to get on 10m phone for less than the cost of one meal out (remember those!?).

My (dated now) ideas were here.

EMF calculator

Quite a few people have been concerned by recent letters from OFCOM about changes to our licences in the future to ensure we do not put members of the public in danger. 

With QRP this is very unlikely, but with high power and beams you may be required to prove this if you were ever investigated.

There are several calculators available to help work this out e.g. on the OFCOM and RSGB websites. I see Steve G1KQH has found another, the link of which is on his blog.

Crystal set DXing


As radio amateurs, we are often after new challenges. One such is DXing with crystal sets.  In the past, there have been some remarkable designs.  

Remember that all the power is provided by the TX station (no batteries, no solar cells etc.), so people struggle to get the strongest signals with decent selectivity. 

Amateur DX is possible, and on 80m I have copied SSB signals at some distance. Of course, this was just envelope detection and I had to use other means to ID the station with certainty. On bands like 10m, it should be possible, at times, to copy DX stations, especially with Es on a crystal set. Signals need to be in the low mVs to be received.

In the days when AM was common on 160m I have copied stations at some distance on a crystal set. Patience is required. People regularly copy 80m AM nets in the USA.

See https://crystalradio.net/crystalplans/index.shtml

See https://sites.google.com/site/g3xbmqrp3/hf/crystalset.  As this page is quite old, some of the links may not work. At some point I really must check and delete any that no longer work.

Remember that old pages, now closed, can often be found on the Wayback Machine.

1933 recordings - NOT amateur radio

Southgate News has some interesting links to some recording made in 1933 on aluminium disks of AM broadcasters.  Of great historic interest.

See http://www.southgatearc.org/news/2021/march/dxing-in-england-1933.htm#.YE3QayuTLrc

King's - NOT amateur radio


Living close to Cambridge it is all too easy to take sights that people come across the world to see for granted . The photo shows King's.