RCA SRT-403

How I acquired this recorder is covered in my story about the Brush BK-401 so I won't be repeating it here. I do have a separate story that involves this machine that is rather unique.

First off, I haven't used the recorder very much although, in its day, it was a pretty fancy model, in fact, it was referred to as the "Deluxe." If features push-button controls and it sold for $169.95 in 1956. I am thinking that its previous owner didn't use it as much as he did his Brush BK-401 based on the fact that the 200 reels of tape I acquired with these machines were recorded primarily before 1956. This recorder, like everything else this gentleman saved, is in excellent condition. My guess is that a cleaning, a lube, and, of course, new capacitors, would bring this gem into like-new operational condition.

In June 2012, my son was visiting from the West Coast and we talked about our "geek points," a silly reference to things we've done that make us "geeky." I got into computers in 1978, long before he was born, eventually teaching computer programming at the high school level and even for one semester at the college level. That really helped me rack up the "geek points." Since I also did things that were ungeeky, like coach high school cross country, that offset some of those points. He, on the other hand, started programming when quite young and had already passed me by in coding ability.

One of the geeky things one can do is to get a project featured on Hackaday, a blog that covers all types of hardware and software hacks. Back in 2006, they featured one of mine, a project that used parts from a 5-1/4" floppy disc drive and an old computer to open a Master combination lock. Since I had put this up as a school project I was a bit reluctant to show how it could easily be modified to "crack" the combination, something many others on that site subsequently did. However, just getting featured on the site was a big deal and I racked up geek points for doing so. I couldn't find a current link to the project on their site but here is a summary with pictures and the software on my own site.

Not to be outdone, my son had one of his projects featured there in 2010, Phone/webapp Written in Ploy to Appear More Popular, which was a combination of several technologies that were not really designed to work together. It was a Tetris game, played on a website, using a phone as the controller. Massive geek points accumulated there.

So, there in 2012, we decided that we should do one together and see if we could get it featured on that site. Since he was raised surrounded by all things analog, and considering how I love mixing old technology with new technology, we brought our interestes and skills together for this one.

There are credit card readers you can get for your smart phone which are nothing more that a tape head in a small plastic case. We picked up a few from Square and disassembled one to see what was inside. It's a tape head and a resistor. We connected it to my guitar amp and slid a credit card through it and, sure enough, we could hear the data on the card. We then held it against a piece of recording tape as it went through my Akai GX-260D and it reproduced the sound on the tape.

The next step was all his. He put together an app for the iPhone that reads the analog data coming from the reader and records it to the phone's memory. We decided to move further back in time so he took pictures of my RCA Model SRT-403 and animated the reels when the app is in record or play modes.

We took the head cover off the RCA to get better access to the tape path. We also had to modify the Square reader a little to reduce the pressure placed on the tape as the original design puts quite a squeeze on the credit card as it's drawn through the reader. The head is mounted on a sort of flat spring and it was a matter of bending things a little to allow a small gap for the tape path.

In keeping with the old-as-can-be analog theme, I selected a big band remote by Art Kassel's orchestra that was recorded off-the-air in the late 40s on paper-backed tape. We placed the RCA in play and pressed record on the iPhone. The current version of his app does not provide audio output at the same time as recording but the resulting sound, on playback, was pretty impressive considering the time lag between the technologies. He shot video (using an iPad) and dubbed the sound in over it to show what was happening.

The video can be viewed here:



We were featured on Hackaday in June of 2012 here:Recording Off a Reel-to-Reel with a Credit Card Reader

Here is the project at his website: Reel-to_Reel

If I was doing this over I would use my Brush BK-401 Soundmirror instead of the RCA. One can't go back much farther in time with reels than that.

The paper tape I used was out of my collection which I have online here: Paper Tape Archive

We were added to the Museum of Magnetic Sound Recording's site.

Later, we were both featured again, in separate projects on Hackaday:

My Intravalometer project from 2014: 1980íS Ingenuity Yields Mechanical Intervalometer

His 2015 project, an Etch-a-Sketch driven by a computer: Automated Etch-a-Sketch Re-produces Famous Artwork



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Updated November 2020.