Showing posts with label 74hc04. Show all posts
Showing posts with label 74hc04. Show all posts

Monday, November 16, 2009

building an oscillator

I'm built an oscillator, for 28.188MHz based on the Genesis Q5 from VK1AA. Well, I had smoke. I'm still working on the plug-in-bread-board. I think the lesson is not to use 12 volt gell cells for testing out new ideas. Can supply far too much current too quickly. Now I understand the little 9 volt battery role in life...

The little 74hc04 squealed then popped! Took only a second. I'd put the 7805 in the reverse position. Its a 50-50 chance ... Lesson there is to not turn the pluging board around all the time and loose track of the orientation of things, I think.

So with the regulator in the right way now, it gets pretty warm, so I've added a heat sink, but not tested it again. Will have another go when the 2 meter AHARS net is on this evening, in the shed.

At the end of this, I might order a G5 or two. I expect that I'll need a few for various prototypes anyway. Just want to get a couple of modular oscillators up and running for receivers =)

72's

Kim - VK5FNET