10m FT8 RX (Sunday)

 At about 0845z, my 10FT8R was turned on on 10m FT8 RX. No spots yet after 5 minutes.

UPDATE 1100z:  7 stations spotted, with furthermost IW8PQ (1928km) in Italy.

UPDATE 1235z: 13 stations around Europe spotted so far on RX.

UPDATE 2110z:   87 stations spotted today on 10m FT8 RX.  QRT.

Little Walsingham - NOT amateur radio

The photo shows Little Walsingham in Norfolk, UK. We stayed here a few years ago. 

Walsingham has been a pilgrimage destination for centuries.

20FT8R or 15FT8R anyone?

Whilst playing with the 10FT8R something occurred to me. With FT8, oscillators only have to be stable over 15 seconds. Many free running HF oscillators are far more stable than this even long term.

So, I think the crystal can be replaced by a just a tuned circuit making this receiver work on any HF FT8 frequency. All that really matters is reasonable long term stability and good short-term stability. All that's required is to scale the RF tuned circuit (one tuned circuit) and set the oscillator to half the FT8 frequency needed. I have not tried this but cannot see why it should not work.

This may work as high as VHF where I have made free running oscillators work even on 2m.

Do not be afraid to experiment! 

This should make the whole receiver very low cost indeed. It would not surprise me if many can make the entire RX for less than the cost of one coffee out.

Nearly gone - NOT amateur radio

Summer has gone and it will soon be time to put in bedding plants to give winter colour. The plants at the front of the house still look OK, but are now past their best. This was the scene yesterday morning.

Sunspots - Sunday October 3rd 2021

 Solar flux is 87 and the SSN 25. A=8 and K=2.

Night Off

472kHz WSPR RX beckoned this evening, but I decided to watch TV instead. Funny how it suddenly seems to have gone dark at night and we have moved into "winter mode".

10FT8R 10m FT8 RX

This weekend, I want to try my simple 10m FT8 RX with 14.037MHz crystals. 

As a benchmark, I want to try first with the original design, then swap crystals but without the toroid near the crystal. I should be able to net the crystal without the toroid.

The simple direct conversion RX uses a Polyakov mixer with injection at half fequency.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/10ft8r-rx .

UPDATE 1400z:  As expected, the even simpler circuit around the crystal works fine with plenty of South American stations immediately spotted. The map shows the stations spotted in just the last 30 minutes on the 10FT8R with the simpler circuit (no toroid) and a 14.037MHz crystal. It works. The revised  circuit is shown on the photo, without the crystal T50 toroid.

UPDATE 1622z: 175 stations spotted this afternoon with the 10FTR on 10m FT8 RX with the simplified circuit. It is impressive.

UPDATE 1746z:  193 stations spotted on 10m FT8 RX with the 10FT8R.  It looks like the propagation is now stopping as darkness falls.

UPDATE 1911z:  QRT. No more stations for some while now.

1971 - NOT amateur radio

The photo shows our wedding day in July 1971. I had hair!

50 years later I am bald and much different.  Where did the years go?

Grandson's crocheting - NOT amateur radio

Our grandson is 12 years old. This is a lampshade he recently did. He is good at art too. 

See https://sites.google.com/view/g3xbm4/home/non-amateur-radio/grandsons-art .

Old cottage - NOT amateur radio

The photo shows one of the cottages in our village. It probably dates from the 1700s.  A few years ago it was extended, not that you would know.