SW-3 Wired Up and Ready to Roll

The amazing National SW-3 – selective, sensitive and with a great signal to noise ratio for a “three tube job” . . . The first “mystery” was which power supply to use – there are three versions of this receiver and each has a different voltage configuration. I purchased what was supposed to work (the “Doghouse”) – and while I got the tubes and…

National SW-3 Lives!

The wonderful 1930’s era National SW-3 was one of the first commercial receivers marketed to the Radio Amateurs. There were three main models – an all DC, all AC and a hybrid of the two. The National SW-3 started advertising in 1931 – and was NEW! in the November QST What is interesting is that up until the late 20’s, hams built their own…

SW-3 Model Two and “60 Series” Coils

This was the last in the SW-3 line. I have a previous model There were several versions of the National SW-3, and they have different power supply and coil (transformer) requirements. At first its a pretty daunting set of configurations to figure out, but luckily, using Google – you can find quite a bunch of great sites. This is one of my favorites: http://www.antiqueradios.org/gazette/SWevol.htm…

SW-3 Project Step 1: Choose and Consolidate

The National SW-3 “All A.C.” Version at KY6R The first thing I had to do is decide which of two SW-3’s I would use for my receiver. The “All A.C.” model won because: It had two of the three coil sets that I wanted – the 40 and 20M band and the upper end of the broadcast band and Top Band (1500 – 2000…

National SW-3: My Latest Project

The 1930’s National “Thrill Box” is an awesome regenerative receiver I am trying to get mine up and running. I actually have two versions – one is the “All AC” model – or ACSW, and the other is the DCSW model – which can be used on AC or DC. Here is a nice page describing both of the units that I have: Rider-1944-MNO-OCR-Page-0191…

The National SW-3

Original SW-3 advertisement The National SW-3 regenerative receiver made its debut in the 1930’s and was designed by James Millen and company. It is a very sensitive receiver that only has three tubes and uses plug in coils for band switching. SW-3 Circuit – so simple I can maintain it and do some restoration if need be There were both battery operated and AC…

A “Tuning” of the Seasons

HRO (National) SW-3 – Circa 1930’s I was lucky to meet Reg – regarding QRP and 1930’s shortwave receivers. This is the SW-3, and here is a video of someone tuning it: https://youtu.be/79GwKtV25dg If you’ve followed my blog – then you know I started out at age 11 in 1970 as a shortwave listener. I built a Heathkit SW-717 receiver and had a blast…