Friday, December 17, 2010

600m QRP TX update

It is about time to hurry up. Just a few more days and my 600m permit will have expired. As my energy slowly seems to be returning (don't ask what drained it - the regular reader may have a clue though), my soldering iron heats up more regularly. Today, the last drips of solder are dropped and the 600m exciter (see earlier post) has been given a "power stage", namely a 74HC240 operated at 8V.

Just applied some power, no keying yet... neither an aerial, just a few centimeters of wire. Still my grabber's AGC was pulled (tx-ing from ground floor through two reinforced concrete ceilings).

The spectrum shows DI2AM at 505180Hz. The signal at 503200Hz (1955z) would be me testing.
The HC240 developed slightly elevated temperature. I guess this is normal when running it at 8V. I said, the signal was not keyed, and it wasn't, however, I was handling the PCB, feeling temperature etc, hence the variation in signal strength.
I hope that, later 2nite, I will have hooked up a QRSS keyer to the transmitter and have it wired up to an aerial (I figure that will be the original Plumbtenna).