23 Aug 2021

Loop antennas

From my own results I think loops are (maybe) 6dB down on a dipole. This is far from accurate, but the losses are likely to be greater on lower frequencies and less on higher bands. 

This is 1 S point, so not too great. For some applications that do not require much frequency change they can be ideal. FT8, PSK31 and WSPR come to mind. 

When I had no external 10m antenna earlier in the year, I used an old Whizz Loop on 10m FT8. Although I may have missed some stations, I still spotted plenty. Mine was just on the shack windowsill indoors.

If you have limited space and can cope with them being very sharp tuned, if efficient, they can be a decent compromise antenna. With QRP you will not need special capacitors. With QRO the voltages at the high impedance points can be very high so special capacitors will be needed.

See https://sites.google.com/view/g3xbm4/home/antennas/loops .

Afghanistan - NOT amateur radio

In the end, I hope the political situation there settles down and everyone is treated respectfully. 

For almost 200 years external forces have tried to "sort the country out".  In the short-term this may have appeared to work. In the long term it has not.

Personally, I am very conflicted: I find the apparent treatment of women and gay people as poor by our standards. However, after almost 200 years and billions of pounds I think we should leave them to it.

I think the evacuation of those wanting to leave is shambolic and could have be done so much better.


Swifts on the move - NOT amateur radio

Swifts are a common sight in the UK skies in spring and early summer. They are often heard screaming in feeding parties on the wing before being seen.

It is some days since I last saw any. I think they are migrating south. The odd straggler may be about, but most will be gone from the UK until next spring.

See https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/swift/ .

10m FT8 QRP (Monday)

Shortly, I shall go on 10m FT8.  Usually I TX at 2.5W for a few minutes and then go RX only for much of the day. Even as the Es season is winding down, I am still copying many stations. 

10m FT8 is ideal as it works with weak, fleeting, signals. Even stations coming through for just 12-15 seconds can be spotted. Although I have not tried it, FT4, although less sensitive, needs just half the time. 

There must be several times when the MUF just peaks at far higher than average.

UPDATE 1040z:  After a very brief period on 2.5W TX (spotted by 4 in Europe and one "near miss" QSO) I am now 10m FT8 RX only. 22 stations spotted, all in Europe by what seems to be Es.

UPDATE 1544z:  30 stations spotted today so far. All EU.

10FT8R

This DSB 10m FT8 RX was in a recent RadCom and is on the g3xbm.co.uk website. It's a very simple circuit but works well and frees up the "big rig". 

Sunspots - Monday August 23rd 2021

 Solar flux is 77 and the SSN 16. A=3 and K=0.

22 Aug 2021

2m FT8 QRP (Sunday)

 After a brief QRP TX period (2.5W, 8 spots of me, but no QSOs), I am now RX only.  So far, 3 stations spotted.

UPDATE 2104z:  QRT shortly. So far this evening 22 stations have been spotted on 2m FT8 RX. See map.

Bells back - NOT amateur radio

We have had a strange year and it was so good to hear the bells ringing out again this morning at our local church. We are still some way from the "new normal", but this is a step on the way. My grandson made this video.

6m - "the magic band"

If you wonder why they call this "the magic band" take a look at this. This is the Australian winter yet still signals were spotted in Europe on 6m!! Remember this is still close to sunspot minimum and this is a VHF band! Most springs and summers very modestly equipped stations can work 1500km or so. 



Doctor's comment - NOT amateur radio

Some years ago (after my 2013 stroke) my doctor said to me, "is it all too much?".  I replied, "of course not". I guess he asks this quite often of old people. 

I guess if I had replied, "yes, it is all too much" he would have interpreted my answer as looking to palliative care rather than seeking a cure in the event of serious illness. Many years later, I get tired easily. Life is more of a struggle. 

If he asked me now though, I would still give the same answer. I guess as you get older you have to adapt and accept that some things you once could do you cannot.