Thursday, November 26, 2009

The Kongsfjord QDFA v. 2 Operational, Veries

One cold, windy morning in the end of October, the Kongsfjord QDFA amplifier ceased working. The reason is most likely static discharge, from which the amp was not protected. Blowing snow creates a lot of static if there's enough snow and enough wind, up to the level when most or all signals are covered in noise, and the Perseus goes into clipping.

So I removed the amplifier from the phaser enclosure, and mailed it to Dallas, who replaced the faulty transistors and retro fitted gas discharge surge arrestors to the input and output of the amp. In addition, Dallas increased the amplification from 10.3 dB to 14 dB.

The amp was reconnected yesterday, and the QDFA was put into action again. I am amazed that the cheap angling rods are still up. Anyway, I think the changes made to the amplifier justifies a "Version 2" label. For those who want to build their own QDFA, fitting gas discharge surge arrestors is probably a very good idea.

Two veries lately:
920 KVEL Vernan UT was a 2008 log; they talked about my reception in a recent morning show.

1340 KBNW Bend OR heard on Nov 23 (with the 310 beverage) when Oregon stations in general had good signal levels.

No comments: