01-19-2021, 01:01 PM
I just started work on my National NC-125, an 11 tube communications receiver. The manual and schematic can be found here: http://bama.edebris.com/manuals/national/nc125/ for those who want to follow along. This is how it looked when I first received it:
[Image: https://64.media.tumblr.com/7f56a0296e9b...922566.jpg]
When I got it, the main tuning dial had a problem which I quickly managed to fix, just a minor mechanical snag. Then I ordered a complete set of condensers for the radio from: https://hayseedhamfest.com/ . This guy is a great source of custom made electrolytic condensers which will fit into older radios and have higher specs than the originals. Now that I am finished with my SW-54 adventures, I got back to work on the NC-125. Today, to begin with, I replaced the one two section can. The work went very smoothly. Here are some pictures. First, the whole underside of the chassis before any work:
[Image: https://64.media.tumblr.com/21deea236ef7...315439.jpg]
Next, a close up of the underside showing the two section electrolytic before replacement:
[Image: https://64.media.tumblr.com/096115084e19...c9ee1b.jpg]
And last a close up of the underside showing the replaced two section electrolytic:
[Image: https://64.media.tumblr.com/c51f3be833c9...d18233.jpg]
I find the liberal use of rosin flux, applied with a little artist's brush, very useful in de-soldering and soldering, especially to large lugs. I make it by dissolving crushed up violin rosin in 91% isopropyl alcohol from the dollar store.
[Image: https://64.media.tumblr.com/7f56a0296e9b...922566.jpg]
When I got it, the main tuning dial had a problem which I quickly managed to fix, just a minor mechanical snag. Then I ordered a complete set of condensers for the radio from: https://hayseedhamfest.com/ . This guy is a great source of custom made electrolytic condensers which will fit into older radios and have higher specs than the originals. Now that I am finished with my SW-54 adventures, I got back to work on the NC-125. Today, to begin with, I replaced the one two section can. The work went very smoothly. Here are some pictures. First, the whole underside of the chassis before any work:
[Image: https://64.media.tumblr.com/21deea236ef7...315439.jpg]
Next, a close up of the underside showing the two section electrolytic before replacement:
[Image: https://64.media.tumblr.com/096115084e19...c9ee1b.jpg]
And last a close up of the underside showing the replaced two section electrolytic:
[Image: https://64.media.tumblr.com/c51f3be833c9...d18233.jpg]
I find the liberal use of rosin flux, applied with a little artist's brush, very useful in de-soldering and soldering, especially to large lugs. I make it by dissolving crushed up violin rosin in 91% isopropyl alcohol from the dollar store.
