Sunday, May 08, 2011

80m DSB/DC transceiver working

After some more work on the ARNSW Home Brew group 80m transceiver challenge it's working well enough for a contact with Patrick, VK2PN who's about 10km away in Manly.



I had run out of NE602s and was using a TUF-1 mixer but some stock arrived in the mail and I've swapped out the balanced modulator to good effect.

Thanks to VK2PN for giving feedback on my signal and generally being encouraging. The PCB construction style lends itself to further tinkering and looks just marvellous to my eye.

Most of the circuit is based on the work of Drew Diamond, VK3XU. The oscillator is a 3.84MHz ceramic resonator that is pulled to about 3.54MHz with a giant capacitor but seems stable enough.

Great fun!

Friday, May 06, 2011

Attempt at 80m portable operation with FT-817

This week I went on the road south of Sydney and while in Bowral I tried portable operation on 80m. It didn't go too well and more work needs to be done on my portable antenna.



Thanks to the chaps from the Manly Warringah Radio Society for trying to receive my weak signal and for providing reports.

Radio nerd's tour of Canberra

I've just returned from a visit to Canberra and while there took some time to see a few interesting things for a radio nerd such as me.

The Australian War Memorial has a bit of home brew radio gear on display. Here's a transceiver with a nifty antenna tuner front right:

War Museum radio

Here's a receiver that is powered from an electric light socket:

Home brew receiverOld parliament house is amazingly accessible and aside from wandering around even in the Prime Minister's office and private make-up room, the press rooms are nicely preserved. Here is what a radio journalist would have used (My first job was at 3DB):

Radio journalist gear

Here's what a print journalist used, complete with spike for stories to be sent to the sub-editor (oh, we don't have them any more do we):

Press journalists gear

There is quite a large typewriter collection on display and the rooms are very cramped. Well worth a visit.