19 Apr 2015

VLF field test tomorrow

Today I adjusted the turns ratio on my 8.976kHz VLF QRSS3 and 10wpm CW 5W beacon to better match my earth electrodes. At this QTH they look much greater than 50 ohms, which I measured at the "old" QTH and optimised for.

On the way I managed to blow up a TDA2003 IC, which I had to replace. The whole exercise was far more exhausting than I was expecting. It seems that after about 10-15 minutes of physical or mental effort I am done in. Before my cerebellum brain bleed everything today would have been trivial. Now trivial tasks feel like climbing mountains! Although I can see progress in my recovery there is still a long way to go. One of my aims (among many) is to be able to resume field tests as before, but time will tell if I am really up to this: it is quite hard when your brain is still foggy a lot of the time. Oddly, when sitting down at home or when driving things are fine. It is when I do something requiring real physical or mental effort that I get tired. I guess the radio work today was hard as I had not done this sort of thing for some time.

Anyway, the good news is that I hope to do a VLF field test tomorrow.  Everything is ready and tested. It will not be until late afternoon as both my wife and I are busy before then. The XYL will be there at the test site if I get really tired.  Setting up the gear will be especially tiring in my current state. The test site is not too far from home. I have soak tested the TX and it should be fine on QRSS3 using my loop and Spectran at the RX end. I shall report results tomorrow. This will be my first VLF field test in over 18 months. How I have looked forward to this. If the loop is successful I may try the E-field probe.

3 comments:

G1KQH said...

Nice to know you had some TDA2003 spares from someone? Hi! Hi!

Roger G3XBM said...

I used my old ones first. And, of course, thank you Steve.

G1KQH said...

Anytime Roger, you know I have a store full!

73