VLF 10 years ago

10 years ago I was totally fit and doing field work below 10kHz. 

Zoom advantages?

Since the start of the pandemic our local Cambridge Radio Club (CDARC) has been holding regular lectures via Zoom. We usually get between 20-30 people attending. 

The advantage is those watching and speaking can be anywhere in the world.  Last night the speaker was in Canada. It felt as if he was next door!

As I am unable to drive in the dark, these talks suit me fine.

Sunspots - Saturday August 14th 2021

 Solar flux is 73 and the SSN 0. A=6 and K=1. 

10m WSPR TX at 500mW

Since 0822z, I have been on 10m WSPR TX. As yet, nobody has spotted me.

UPDATE 0840z:  Already 4 spots from 2 unique stations. Looks like Es.

UPDATE 2056z:  26 unique stations spotted me today.

6m FT8 QRP (Friday)

Since 0822z I have been on 6m FT8. Apart from a very brief TX period at 2.5W to the V2000 vertical omni with the furthermost a spot by YO8SSB (1874km), I have been RX only. So far this morning, 4 stations spotted. Es is just starting I think.

UPDATE 2104z:  179 stations spotted on 6m FT8 RX today as the map shows.

Parsonage Farm - NOT amateur radio

 

This is Parsonage Farm in our village. 

Arecibo Observatory and EME

Sadly this giant radio telescope in Puerto Rico was damaged beyond repair. 

In the mid 1960s it was used for some amateur moonbounce tests. Many amateurs made their first EME QSOs this way. The dish gain was very high with a 1000 foot dish! I have no idea what the ERP was.

This was 1964 (?), way before we had any weak signal modes that makes EME a little easier. EME still needs optimum equipment and is not for those not prepared to work hard.

I am not sure what is needed these days to work the better stations via EME, but I would guess at least 100W, mast head preamps and as big a yagi array as you can manage. This also requires accurate moon tracking, low cable losses and weak signal modes optimised for EME.

Re-tarred - NOT amateur radio

For the last 2 days they have been applying tar to the outside of the restored windmill next door. This is 200 years old and they last coated it 8 years ago.

It looks splendid, although a few drops from starlings on the sails could soon spoil this!

All the work is done by volunteers.

Tunnel diodes

Back in the 1960s these were all the rage.  I remember making a simple tunnel diode oscillator at university in about 1969.

I am not sure if you can buy them still. They are 2 pin negative resistance diodes that work by quantum mechanical tunnelling. 

Very simple uW TXs are possible and there was one published that was copied about 200km away in New Zealand on 80m.

See https://en.wikipedia.org/wiki/Tunnel_diode .

See https://www.rfwireless-world.com/Vendors/Tunnel-diode-manufacturers.html .

Sunspots - Friday August 13th 2021

Solar flux is 74 and the SSN 11 . A=4 and K=2.