Big Ben - a 119 year old recording

Not ham radio, but just spotted this fascinating recording of Big Ben chiming. It was made on a wax disc 119 years ago in 1890.

Geminids meteor shower tonight

This evening the Geminids meteor shower should peak between 2000 and 2200z in the UK.  As there is no moon visible and the sky should be reasonably clear it could be a fine sight. Increased meteor activity should allow European DX on bands like 50MHz and 144MHz by meteor scatter (MS). Best place to listen/look is on 50.230MHz in JT6m mode.

YO5OFJ's pages with everything

Vanyi's Homemade/homebrew HF transceivers page is a collection of lots and lots of circuit ideas showing transceivers from 160m - 10m created by various people over the years. It is a good place to look for ideas when thinking about new projects.

DSB mod for the Heathkit HW8

When looking around for ideas for DSB rigs I found a page which shows how to modify the HW8 for DSB operation by adding a balanced modulator and audio stages.  KL7R reports that he worked New Zealand using the modified HW8 on sideband.

Received in Norway on 500kHz

Last night, a couple of LA stations were listening on 500kHz WSPR. Neither had heard my 1mW QRP signal by 2300z, so I left the station running through the night. At 0418z LA9BEA heard my signal at -28dB S/N in JO29 square some 836kms to the north east of me. This is now my 8th country, and 49th station, to log me on the band.

NMRevue Magazine (from Belgium)

Just found a link which takes you to back numbers of the NMRevue magazine from Belgium. I'm not sure if this is a club/regional magazine or a national magazine, but it does have quite a few nice constructional articles in each issue. Unfortunately you will need to read French to fully enjoy this.

Rising sea levels - what would happen?

Whatever your views on the causes of climate change, it is a FACT that the Earth is currently warming and sea levels are rising. This interactive map allows you to put in the likely sea level rise, in 1m steps, to see how the coastline would change. Some places are little changed but others are e.g. The Netherlands and the Fens in the UK.

A draft text for an agreement on climate change reduction has been released today in Copenhagen. It needs a lot of work.

Classic 10m DSB TX

There was an article, in 73 Magazine back in the early 1970s, about a simple crystal controlled, 1W 10m DSB transmitter. This was reprinted in a Dutch magazine and in RadCom. The schematic had at least one error (one diode in the mixer wrong way around, that I have corrected here), but it is a useful "ideas" starting point for a DSB transceiver. This circuit used PNP transistors. Today I'd use NPN 2N3904 devices and T37-6 toroids everywhere.

ON/F6CNI on 500kHz

This evening, conditions have been very good on 500kHz with almost continuous reports from GM4SLV up in the Shetland Is 896kms to the north. Also tonight, a new reporter ON/F6CNI in JO20 square at 424kms. His reports were very strong (-2dB S/N). This brings my total to 48 unique reports on 500kHz WSPR.  Tonight I've been using the new version of the transverter on the small, tidy, board (see picture on earlier blog entry today). This should be boxed tomorrow.

SAQ (17.2kHz VLF) reception

This link takes you to a recording of SAQ on 17.2kHz as heard by M0LMH in IO93 square.  It is quite strong when the signal starts. I listened on the Dutch online SDR and SAQ was not as strong there as I would have expected at 1600z. This is a recording of SAQ in Connecticut USA made by Jay W1VD earlier today.