Review of Ceramica ceramic bearing fans

For some years I have used Ceramica muffin fans for low noise and long life. They use a ceramic bearing which is quieter than ball bearings, but longer life than sintered bronze bearings which dry out.

FanImpeller

In the last month, I have replaced three Ceramica fans that have failed, one with less than a year’s service and two with less than one month’s service. Continue reading Review of Ceramica ceramic bearing fans

Spoiling balun action with ‘shielded twin’

In a QST column in 2008, a correspondent asked the question

… I have the ladder line terminated to double coaxes that run about 12′ (4m) inside the house to an antenna tuner. Should this pair of coaxes be grounded at one end or both ends?

ShieldedTwin

The Doctor gave a detailed diagram (above) and his advice was… Continue reading Spoiling balun action with ‘shielded twin’

VK3FI QRSS on 473kHz – 19/06/2014

Some four months ago I sent VK3FI in Mildura a QRSS keyer to try on his 600m beacon. The keyer hardware and message content are described at Simple Morse beacon keyer for VK3FI on 600m.

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Above is a capture with Spectran received at my location in Bowral tonight 760km east of VK3FI, QRSS3 on 473.000kHz (well perhaps 2Hz higher, Dial freq 472.2kHz USB for the above display). Continue reading VK3FI QRSS on 473kHz – 19/06/2014

owenduffy.net performance improvement

I have been concerned at slowly degrading performance on my web sites, coming to a head with migration to WordPress (this blog) about six months ago.

To improve performance, I have migrated all content to a new hosting service on Godaddy’s latest cPanel hosts.

It is a substantial amount of work, and I think everything is working properly. It is certainly much quicker and consistently quicker (at the moment) on the WordPress application.

Though I have taken care in specification of character sets, it appears that special symbols have been trashed in the migration. I have done some global search and replaces and think I have found and fixed all (or most) problems. Credit to the Search Regex add-in.