Building a wax cylinder player

A band called The Men That Will Not Be Blamed For Nothing is putting one track of their next album on a wax cylinder available from 1 June. Don't ask me why! This is about an attempt to make a wax cylinder player to play the new record when it becomes available, the first commercially produced cylinder in 100 years.

See http://news.bbc.co.uk/1/hi/technology/10171206.stm

0.5km on earth-mode with 4W

This evening I achieved my best results so far with 1kHz earth mode TXing on a 20m base electrode pair and receiving on an 80cm loop and listening by ear. Even this range I think can be bettered with yet more 50Hz rejection. With a PC at the receiving end I think 1km is certainly possible now.

Computer mouse problem

You must read this http://myweb.tiscali.co.uk/wgtaylor/FM.pdf . It is a true account of a PC problem that really did turn out to be a mouse problem ....a real mouse inside the PC that is.

Resonating the VLF receiver loop

Today I've been resonating my receiving loop to see if this improved things. Well, I tried it - no better. Then I improved the active high pass (50Hz) filter which got the mains hum down some more, removed an audio gain stage in the RX just leaving 2 common emitter stages. With this, 4W TX, and the loop resonated around 2kHz I did a further walk-about test. 0.42kms was the limit of range. S/N better and 50Hz hum not a problem even close to cables. The RX needs some more gain and narrower selectivity.

More earth mode experiments at 1kHz

This evening I extended my TX electrode spacings by connecting one end to the copper pipes in the house, almost doubling the effective TX baseline to about 20m. With this, my "earth mode" signals were much stronger and I was able to cover further than before in a "by ear" walk-about test around the fields locally.  Ultimate range tonight was 0.4kms using 4W (probably less as the TDA2003 was hot and probably turning down the power) and receiving on an 80cm 30t loop, active HPF, small AF amp and crystal earpiece.  Range was limited by 50Hz mains hum and background sferic noise. I must retry this set-up with my HF up-converter and FT817 this week, which has good rejection of 50Hz (and its harmonics) as well as a narrow CW filter.

San Marino on 6m QRP

Just worked T77C on 6m Es with QRP SSB. I think I've worked this station some years ago but it is one of the less common Europeans and a first for this season.

6m Es

Only had a brief chance to operate today as I was busy in the garden then out at a BBQ in the hot sunshine, but managed to work some 6m QRP Es this afternoon. Although I worked some DX last week when out pedestrian portable, this was the first 6m Es QSO this season from home. In the coming weeks we can expect 6m to be open for DX most days.

Tame Robin

Whilst out portable in Devon last week I was "visited" by this very tame robin who came so close he ate an ant from my hand. I was able to take a really close-up picture from about 20cms away. In the USA the American robin is a totally different, and larger, thrush sized bird. In the UK it is not uncommon for robins to be so tame they will come very close to you when gardening and they can be trained to eat from your hand. There was a good book called "The Life of the Robin" by David Lack published by Fontana in their New Naturalist series. This is no longer in print.

Pedestrian Portable webpage added to site.

See http://sites.google.com/site/g3xbmqrp/Home/portable for my thoughts and tips on portable HF SSB DXing. If you have further thoughts or tips please let me know. Also, I'd be interested to hear about results YOU have had with true handheld HF DXing.

M0BMU's latest complete 8.97kHz Portable Receiver

Jim Moritz M0BMU has updated his loop/preamp circuit for 8.97kHz turning it into a complete direct conversion receiver for 8.97kHz. He posted this on the LF reflector in the last few days. I have added this to my sub-9kHz website (scroll down for Jim's description and schematic on the webpage. See http://sites.google.com/site/g3xbmqrp/Home/10khz