Great history lesson! I look forward to all your videos. Your efforts and great video detail are greatly appreciated. Thanks.

Love the bonus history lessons! Almost all my herd has the marks. Never seen that model before. Reminds me somewhat of the Zenith Caroline’s. Great video as always. Never thought to bring my radios to the park. Might have to do that some evening for some AM DX. That’s all I get up here stations.

Although I'm not old enough to have worked in the broadcast industry during conelrad, I saw the remnants of it. There was a switch at the transmitter which would engage several relays in the transmitter and at the antenna tower to retune to the conelrad frequency. The transmitter was switched on and off in sequence with other stations on the frequency by a signal from a telegraph circuit from a central control point.

Loved it! Love your narration, nice and softly spoken, very clear! Good Job! Subscribed!

I remember duck and cover when I was a child in the 60's. My dad had a transistor radio in his work truck with the CD triangles on the dial. His work truck did not have a am radio in the dash. I miss what am radio used to be with music all over the band scan. Great info on conelrad. Thanks for sharing. 😂

Great stories and work on that Zenith 👍

Howdy From ELP..... recently picked up Houston AM 740 DX'n a couple night s ago.

I've been collecting radios for years and I never knew the details on Conelrad

I do recall a time when the civil defense system was tested. All the "normal" radio station transmissions went off the air and the CD radio transmissions came on. My research indicates that selected normal broadcast stations were equipped to broadcast on the 640 and 1240 frequencies. Radio dials in that era were not very accurate, so listeners would typically find the CD stations near the markings on the dial, but not exactly on. The triangle marking was probably more common than the letters CD. Zenith used and promoted their "hand crafted" assembly for many years after competitors had switched to printed circuit boards. We see that this chassis used point to point wiring. GE introduced its "mechanized chassis" in the early 1950s. Most of the component leads went into solder wells. Leads did not need to be fed through holes and looped around terminals. Probably the "mechanized chassis" was less error prone as well. Zenith did adopt the "mechanized chassis" later before introducing circuit boards sometime after that. You mention replacing the cord with one that has a polarized plug and moving the switch connection to the hot lead. Max Robinson makes the same suggestion on his funwithtubes dot net site. Placing the switch in the neutral lead was fairly standard practice. Very early "all american five" radios used tubes where the filament voltages did not add up to the line voltage and the extra resistance to build it out was provided in the line cord. So, the line cord had three wires, a hot low resistance lead, neutral low resistance lead and the build out resistor lead. The manufacturers would have had to use a two pole power switch or put the single pole in series with the neutral lead. They chose the less expensive single pole. I think that set a precedence and they continued that arrangement after a set of tubes building out the filament string to line voltage was developed. Early "all american five" radios had the metal chassis connected to circuit ground. The screws through the bottom of the cabinet posed a shock hazard, since they could be electrically hot. If a knob were missing, an electrically hot shaft could be exposed. Even if the knob were in place, it was possible to make electrical contact with the set screw with wet hands. Some people set up radios near the bathtub. We were taught not to do that because of the risk of electrical shock. Radios were common in kitchens and created the same hazard. Later designs isolated the chassis with a capacitor, as this Zenith does here. Later, plastic shafts were used for the knobs. The tuning capacitor was still electrically hot and could often be reached by fingers poked through ventilation holes in the back. Zenith tucked the tuning capacitor under the chassis in this model. I haven't found any data on how many people were electrocuted by these radios. Modern electronics is much safer and people aren't used to being extremely careful. I would suggest going further and replacing the polarized cord with a ground fault protector cord scavenged from a hair dryer. These cords are typically thicker than the original radio's cord and the cord's hole in the back of the chassis will probably need to be drilled out to accommodate a larger grommet and the cord.

Sure is clean for it's age. Those bottom mounts for the I.F.'s are unusual.

Watch what you let touch hot tubes. It looks like the new power cord was draped around the 35W4 rectifier, which gets pretty hot.

Thanks for the history lessons. Dad explained the CONELRAD system to me when I was a kid. When we got a new car in '67, it didn't have the symbols on the radio, and I was really concerned about what we would do if there was a war. Dad assured me we would be OK (I was 8). Nice job on the radio - and go Rangers!

Currently, I am much more worried about Y2K, and 2012..

With all that crap on your workbench, how do you manage to fix anything?

Kind of a crude, macro frequency hopping.

couldn't resist this AA5 investigation and rescue. only watch Shango066 radioTVphonoNut iz good, just the system of watching these evaluations can be Similar. In-N-Out burger Randy's Donuts alongside Talc Ore is exceptional