17m FT8 RX with the loop (Tuesday)

At 0615z, 17m FT8 RX with the indoor loop antenna was turned on. This antenna sits on the shack windowsill. See photo. Just one station spotted at 0640z.

UPDATE 0843z:   63 stations spotted on 17m FT8 RX with the furthermost JA3APV (9407km).

UPDATE 0926z: A brief QRP TX period resulted in nobody spotting me. 90 stations spotted on 17m FT8 RX today so far. My antenna is a modified Whizz loop with central heating pipe instead of wire for the loop. This makes tuning harder (sharper), but the loop is more efficient. I am sure a big beam would be better, but the tiny loop actually performs pretty well!

UPDATE 1610z: 524 stations spotted so far on 17m FT8 RX with this system. I am amazed how well this loop does considering it is tiny, fixed and indoors. Must try it on 15m FT8 tomorrow What has surprised me is not a single station from South America has been spotted.

UPDATE 1830z:   650 stations spotted on 17m FT8 RX today. 17m seems a good all round band, until the evening at least.

UPDATE 2154z:   695 stations spotted with the tiny loop on 17m FT8 RX in the last day.

Sunspots - Tuesday March 8th 2022

Solar flux is 118 and the SSN 84.  A=9 and K=2. 

17m FT8 RX (Monday)

At 2008z, I turned on 17m FT8 RX using the tiny loop antenna on the shack windowsill. So far, 4 USA stations spotted. I suspect the band is just closing.

UPDATE 2117z:   9 stations spotted.

UPDATE 2140z:   It seems the band has now closed.  QRT soon. I may try again tomorrow morning.

UPDATE 2207z:   Not quite closed!  There are still Ws coming through, so I have left things running a bit longer.

Spring blossom - NOT amateur radio

A sure sign of spring is the appearance of blossom on the tree near our post office. It looks great right now, but it will soon be gone.

Loop TX antenna

Last year, I used this tiny antenna on many HF bands. 

It is only about 50cm across and sits on the shack windowsill, but worked remarkably well on FT8. 

I must try it again on bands like 17m.

SW broadcast interval signals

 See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/sw-interval-signals .

This was created a long time ago, so I hope the links still work.

10m FT8 RX (Monday)

 At the moment I am on 10m FT8 RX. Plenty coming through. 

UPDATE 1710z:   500 stations spotted on 10m FT8 RX today.

UPDATE 1926z:   603 stations spotted. Stragglers are North and South Americans mainly. QRT soon.

Oscar 100 activity

Every few weeks I take a peek at activity on the geosynchronous satellite Oscar 100. Activity levels are similar to the last time I looked: not high and still plenty of space. 

See https://eshail.batc.org.uk/nb/ .

Sunspots - Monday March 7th 2022

Solar flux is 116 and the SSN 82. A=18 and K=3.

Low pass filter design

With my upcoming permit to test on 8m, I may need to add external low pass filtering to ensure my TX is totally clean. There are several circuit calculators on the Internet. The one below is an example. It seems daft to buy one when a simple one can so easily be made.

See https://rf-tools.com/lc-filter/ .