Friday, March 04, 2005
Cheap Wireless Headphones
THE PROBLEM:
I spend a lot of "computer face time" at work, so music is often a necessity for getting things done. I was always knocking over stuff on my desk with the 6ft wire to the headphones I use to listen to music on my computer. I looked into getting wireless headphones, but they typically cost around $50-100 which is definitely out of my price range for just a pair of headphones.
THE SOLUTION:
Cheap headphones by broadcasting my own FM radio station!
Well, that's a bit of a stretch. I bought a cheap FM transmitter (SI-Link, $18 at Target) and broadcast my music to a headset radio. See the FM transmitter in the image (with a CD player) below.
Despite what the link to the above product says, the trasmitter can transmit in a continuous tunable range from 88MHz to 89.5MHz, per the label. Here in Austin we have a powerful radio station broadcasting at 89.5MHz, so I set the frequency as far "left" as I could, tuning in at 87.5MHz. (Note that there is a little offset between the advertised frequency and what it actually does).+
Don't bother to listen in, my broadcast coverage is about 15 feet, much smaller than the 50 feet advertised, although I can occasionally hear my music when walking to the printer.
At first the sound had a lot of static until I realized that my computer volume was set too low. Since before going "wireless" my only volume control was on the computer, the sound was set to a comfortable level. By increasing the computer's output volume and reducing the headphone radio's volume, you increase the SNR (signal to noise ratio, in radio speak). Increasing SNR is a fancy way of saying that you reduce the static in your signal.
In addition to that, being a gadget gearhead, I had to take apart the FM transmitter to see if I couldn't improve the antenna somehow. Removing the screws and prying it apart, I was able to find a single long red wire behind the circuit board that serves as the unit's antenna.
Using a knife, I made a little notch in the plastic covering and guided the wire through the notch to the outside world. So now the FM transmitter has a red wire sticking out the side, which I haven't yet scientifically proven to improve the reception.
So now I'm jamming away to "Dan FM", my own little personal radio station at work-- no strings attached.
Only wish is that the company who makes the SI-Link provided where I could get the DC adapter to go with it. Looks like I may have to hack that one myself...
--IG
I spend a lot of "computer face time" at work, so music is often a necessity for getting things done. I was always knocking over stuff on my desk with the 6ft wire to the headphones I use to listen to music on my computer. I looked into getting wireless headphones, but they typically cost around $50-100 which is definitely out of my price range for just a pair of headphones.
THE SOLUTION:
Cheap headphones by broadcasting my own FM radio station!
Well, that's a bit of a stretch. I bought a cheap FM transmitter (SI-Link, $18 at Target) and broadcast my music to a headset radio. See the FM transmitter in the image (with a CD player) below.
Despite what the link to the above product says, the trasmitter can transmit in a continuous tunable range from 88MHz to 89.5MHz, per the label. Here in Austin we have a powerful radio station broadcasting at 89.5MHz, so I set the frequency as far "left" as I could, tuning in at 87.5MHz. (Note that there is a little offset between the advertised frequency and what it actually does).+
Don't bother to listen in, my broadcast coverage is about 15 feet, much smaller than the 50 feet advertised, although I can occasionally hear my music when walking to the printer.
At first the sound had a lot of static until I realized that my computer volume was set too low. Since before going "wireless" my only volume control was on the computer, the sound was set to a comfortable level. By increasing the computer's output volume and reducing the headphone radio's volume, you increase the SNR (signal to noise ratio, in radio speak). Increasing SNR is a fancy way of saying that you reduce the static in your signal.
In addition to that, being a gadget gearhead, I had to take apart the FM transmitter to see if I couldn't improve the antenna somehow. Removing the screws and prying it apart, I was able to find a single long red wire behind the circuit board that serves as the unit's antenna.
Using a knife, I made a little notch in the plastic covering and guided the wire through the notch to the outside world. So now the FM transmitter has a red wire sticking out the side, which I haven't yet scientifically proven to improve the reception.
So now I'm jamming away to "Dan FM", my own little personal radio station at work-- no strings attached.
Only wish is that the company who makes the SI-Link provided where I could get the DC adapter to go with it. Looks like I may have to hack that one myself...
--IG
