Monday, November 14, 2016

NC-109: The final chapter.

Since the last post, I was able to "tweak" the Pullen Mixer circuit enough so that the radio works reasonably well, so I'll leave it in place as a tribute to W8NYI, the fellow who I believe perfomed the modification.

When I say "reasonably well", the radio now aligns properly - the dial tracks the oscillator and RF amp perfectly, but the RF gain seems down a bit, probably due to the difference in conversion gain between the two mixers.  Nevertheless, the sensitivity is totally adequate for shortwave.

So, the old girl is cleaned-up, tuned-up and, as shown at the top right of the above picture, happily among friends.

Oh, one interesting thing that I meant to talk about the other day - this set has seen a LOT of use: Check out the wear on the dial string "pulleys":

These pulleys don't turn (not meant to), the cord is meant to slide in the somewhat polished surface. In this case, it actually started to saw it's way through the copper!  Fortunately, an easy work-around was to simply restring the cords (one main, one bandspread) to use the unused half of each pulley, which works just fine.

So, another project added to the "done pile".  I've got a couple of ideas for what to take-on next, but first, I really need to clean the shop/shack... it's gotten completely out of hand :-)

73 - Steve N8NM

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