Turning it on for the first time was fun but a little tense. Good news, limiting the extra work needed to make the radio safe. The isolation stand-offs - intended to separate the radio ground from the case and therefore avoid shocking the operator - seemed intact. The plastic tuning window for example really benefitted from a little extra attention. This radio is very clean, but I spent some time disassembling the case and cleaning the parts. It was a new idea to me when I watched his video, but he makes a persuasive argument. It’s easy to determine the orientation using a method described in a “ Mr Carlson’s Lab” video. The new orange-drop caps also have an outer foil side, but it is not indicated reliably. This indicates the outer foil side of the capacitor and is usually oriented to the ground or lower-potential side of the circuit. If you look closely at the old wax-covered paper capacitors, you will notice they have a black band on one end. One thing to note: non-polarized capacitors can still have a “correct” orientation. Since this radio isn’t especially rare or valuable, I decided on the “hook” method. This is substantially easier but a little less tidy. Given the tight spaces this can be difficult, and the other strategy is to simply clip the leads close to the old capacitor, form the remaining leads into small hooks and connect them with matching small hooks on the new caps. In a perfect world, one would remove the old capacitor by desoldering it from the terminal strips - leads and all. In this case, there were 11 caps to change, and some of them were in very tight spaces. There are at least two schools of thought on the process. I found not only a suitable substitute multi-section electrolytic but also “orange drops” at Amplified Parts online. The waxy paper caps are often replaced with polypropylene “orange drop” capacitors originally made by Sprague and now made by Cornell Dubilier. The radio has a multi-section electrolytic filter capacitor – often hard to find since they haven’t been in common use for several decades. I made a list of the replacement capacitors I would need. #Ten tec triton iv review manual#Luckily, I was able to find a user manual for the radio online, and it contained not only a schematic, but also a parts list. I decided to replace them all before even turning the radio on. Being at least 60 years old, the electrolytic filter capacitors were likely dried out, and the waxy paper capacitors were probably also faulty. Looking inside, I found what I suspected were failed capacitors. Pretty clean, but the waxy paper and electrolytic caps will have to go One can get a lethal shock by simply plugging the radio in and turning it on. This radio is the AC/DC “hot chassis” type, meaning it was made before modern shock hazard protections like polarized plugs were in place. Old tube equipment can be tricky, and is almost guaranteed to have problems. It languished in the shop for several months (always too many projects and too little time!) but I was finally able to give it some love. It has CW (morse code) receive capability and a stand-by switch - perfect for the beginning ham in the 1950’s and a good radio for my small collection. It is an “all American five” design - meaning it uses the same five vacuum tubes that nearly every other AM Broadcast receiver of the era used. Made between 19, it was popular in its day and covered the AM Broadcast and shortwave bands up to 30 MHz. Once home, I set to work researching my new toy. I sensed a new trip down the rabbit hole! National SW-54 Schematic The price was right, it was cosmetically pretty good, and appeared to be complete. There was this one shortwave radio however - a National SW-54. Some of them were really old, and a bit rich for my blood. To my delight, there was one vendor who specialized in old radios and phonographs. Cosmetically good with just a little surface rust I wasn’t looking for anything in particular, but old tools, radios or cast iron always get my attention. It was our first time to this meet, and we didn’t really know what to expect. Marilyn and I enjoy the odd flea market ramble, and a trip to Bussey’s in Schertz, Texas was fun.
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