Sunday, January 17, 2010

Ramsey QRP80C first steps

Started the kit. This one seems one deep from the archives. Not only the smell of the components, but also their design I have not experienced in decades! Example: 10k resistor on a strip, pre-bent (!) with a cove in one leg to define insertion depth. Honestly, I should not have used those parts, they are something for musea!

OK, used the parts anyway. This is what I have (not) done so far:

  • ignore all the receiver connection parts
  • build the oscillator (unmodified)
  • test as suggested (result: nothing!!!)
The average builder would have given up at that stage, I believe.
My observation was the following, by slowly ramping up the current limiter of the power supply, suddenly the oscillator comes to life. Extremely unstable however. I figured it may be due to the stone age crystal, so I replaced it with a brand new one. Oscillation now pops in much more easily, however, not within the promoted 5kHz but all over the place. So, pulling is am issue here. After removal of one of the two pulling inductors, the oscillator was alive. No stupid ramping up current starts anymore. So, back in goes the old crystal... no oscillations! Hence, I believe the combination of a (gone) bad crystal and over ambitious pulling is an issue with this kit.

I am curious about the rest of it...