| Author | Message | ||
     Hunter (Baseballplayer) Junior Member Username: Baseballplayer Post Number: 5 Registered: 6-2005 |
is there a crystal clock oscillator in anyhting i have around the house or could get at the store? | ||
| Hunter (Baseballplayer) Junior Member Username: Baseballplayer Post Number: 6 Registered: 6-2005 |
i have an old computer where in it would i find the oscillator? | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 503 Registered: 12-2004 |
You are unlikely to find a 1 Mhz oscillator in things you have lying around the house. | ||
| Anonymous |
Yes,You should buy 1Mhz oscillator from RadioShack | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 547 Registered: 12-2004 |
The last time I checked, Radio Shack did not offer them. | ||
| Anonymous |
could he use a crytsal instead | ||
| Anonymous |
*crystal | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 554 Registered: 12-2004 |
No, he needs an oscillator. A crystal is just a rock. It won't send a signal. | ||
| scwis Unregistered guest |
There are a variety of older computer interface cards that have oscillator cans on them - unfortunately, these do not operate at AM BCB freqs. As any ham radio enthusiast will tell you, however, fundamental frequency output is only one of the many signals that come out of an unfiltered oscillator. Third and ninth order harmonics can be especially strong, depending on the manner in which the can is manufactured. A 4.5 MHz can might be present on 1.5 MHz, also known as 1500 KHz at the high end of the dial. A 9 MHz can might come in fine on 1000 KHZ, towards the center in the AM BCB. On the other hand, if you happen to have access to a shortwave receiver or a scanner that gets the aircraft bands (AM modulation), you can probably use one of those to receive the fundamental freq of a transmitter based on a PC oscillator. If you find any really old cards (ibm XT days) you will find some cans that run pretty low, perhaps all the way down to 2 MHz. Older modems have cans in the 3 - 33 MHz range, and older EGA video cards frequently have 24 - 44 MHz cans. Older VGA cards and 486 MoBos will have cans that run up to 66 MHz. Sound cards have all kinds. WARNING!!! Low power radio experimentation is not welcome in all bands :-) The higher freq cans could throw out a bit more range, too, simply because the higher frequencies are easier to match to a short antenna. Higher freqs depend less on grounding, as well. Using a PC oscillator takes your project out of the realm of what this site proposes, but if you're careful it could be fun. | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 591 Registered: 12-2004 |
Another problem with this idea is that if you use an oscillator with a frequency that is common in computers, then all the nearby computers will compete with your signal. | ||
| Anonymous Posted From: 68.106.22.216 |
what about building one with an inductor capacitor circuit | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 596 Registered: 12-2004 |
Go for it. I chose the crystal oscillator because the entire circuit is already there, making it easy for kids to build and get right. Building a transistor circuit to oscillate at a megahertz is not so easy for them to get right. The oscillator always works right off the bat. The usual problems are connecting an 8 ohm sound source (most kids try to connect their ipods to it, and the ipod doesn't have the power to make it work). |
