Thursday, March 3, 2011

Transistor radio hack: playing an Ipod through a vintage 1957 Emerson 888 Pioneer Transistor radio

Vintage sound anywhere with old audio chain. Listen to your favorite oldies in the radios that they were meant to be played on.

Just completed restoring then hacking an Emerson Model 888 Transistor Radio. This radio was built in 1957 and uses a total of 8 transistors.

I restored it following the usual antique radio restoration procedures here:
http://glcharvat.com/website%20pdfs/MIT_Haystack_Open_Lunch_Oct_21_09.pdf

I then modified it so that the ear phone audio output jack would work an an audio input jack by locating the envelope detector and re-wiring the ear phone in-line with the envelope detector and the volume potentiometer as shown in the schematic here:  http://glcharvat.com/website%20pdfs/trans_radio_hack.pdf


More photos and info about this project is shown here:
http://www.glcharvat.com/Dr._Gregory_L._Charvat_Projects/Emerson_Trans_Photos.html

Anyone can do this project, it is very simple and fun!

10 comments:

  1. Hello Dr. Charvat! I have a 1961 RCA Victor 1T1 transistor radio which I would like to hack as you have done with your Emerson 888. The problem is that I know zilch about electronics so even though your schematic for the hack looks simple enough, I do not understand how to proceed. I was able to download a pdf of the original RCA Victor "1961 Radio Servicing Information" (schematic) and that has helped me locate the detector diode. I'm not exactly sure where the AVC feedback resistor is, though. Am I correct in assuming that two of the wires from the earphone jack must be removed from the circuit board and relocated elsewhere? If so, where? Also, must the ground wire from the earphone jack stay in its same location on the circuit board? I realize your blog is mostly for people with an electronics background and I know you must be very busy so I fully understand if you don't have the time to walk this "electronics boob" through the hack. I suppose I can always turn the radio into a speaker for the iPod (I understand how to do that) but I prefer your hack since it maintains the functionality of the AM radio. Anyway, thanks for your time and I hope to hear back from you. Best--Jack

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    1. First step is to locate the volume potentiometer (pot). Remove the middle wire from the volume potentiometer. Try connecting your iPod across the center pin of your volume pot and the ground of the radio, which should be the metal collar around your ear phone jack.

      You should be able to play the iPod this way without any trouble.

      If this works and you want to take it a step further you can go 2 ways:

      1. install a 2-way switch which connects the center pin of your volume pot to either your iPod or to the original wire in your radio.

      2. the way i describe in the schematic for this project. If you can figure out the above then you will be ready to implement this.

      Good luck!

      Greg

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    2. Thanks for the instructions, Greg! I appreciate your expertise and time.

      Jack

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    3. Eureka! The RCA Victor 1T1 works to perfection as per your schematic. I finally understood it! What a simple and elegant solution! Thanks again, Greg. "So come on and let the good times roll..."

      Jack

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    4. Good luck Jack, it's very fun, you will be the life of the party with this retro sound system. It is the source of instant fascinating conversation and reminiscing about old things in general.

      If you haven't already done it, you need to make an long playlist of songs from the era of your radio so that it becomes your virtual radio station...

      Have fun!

      Greg

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    5. Hi Greg,

      Only popular songs from the '50s and '60s will ever be played on the radio! Radio really changed in the '70s as FM was where it was at with its album format and stereo. I succumbed to it at the time, as most high schoolers did, but I eventually found my way back to AM radio in the mid-'80s. Unfortunately, here in the L.A. area, there are no more oldies stations on AM so that's why I am so thankful for your hack.

      I'm also working on a re-creation of '60s L.A. radio by cutting up airchecks from 93 KHJ Radio and their famous DJ, The Real Don Steele. Using those approximately one-minute spots along with KHJ jingles and my favorite songs from the era piped through the RCA Victor transistor radio and I've got a time machine set to when I was a kid listening to that same station.

      Oh, and I'm gonna help a buddy of mine convert his early '60s Arvin transistor radio next week...

      Jack

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  2. Hi! The links for the restauration and schematics are not live anymore. Can you post those links again please? I have the same radio and this is exactly what I'm looking for!

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  3. @boggusfeed

    I've updated the link to the schematic. Thank you for your help!

    Send me photos once your radio has been restored.

    Greg

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  4. I just received one of these for my b-day from my wife. I am looking to attempt the modification, but the soldering iron is not my best friend. Even a pencil any I have had many bouts.

    Thank you for the idea. I'll let you know how it goes.

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