| Author | Message | ||
     Andrewww |
I have a problem.I didn't found an oscillator with 4 pins,but I have a 4mhz oscillator with only 2 pins and I don't know how to connect it.Here's what it's written on it FT 4.000 MHz.Is this suitable?If yes,please tell me how to connect it | ||
| Simon Quellen Field (Sfield) |
What you have is a crystal. It is used in an oscillator to control the frequency. An oscillator has the electronics needed to excite the crystal and produce a waveform. Also, a 4 megahertz oscillator will not produce signals you can pick up with an AM radio, since the radio can only tune between 0.500 megahertz and 1.8 megahertz. You can buy a 1 megahertz oscillator here. | ||
| Andrewww |
Thanks.One more question:what should I add to the Three peny radio to make the signal strong enought so I can hear it with an 8 ohm 2W speaker(without using the Piezoelectric phones)? | ||
| Simon Quellen Field (Sfield) |
What you need is an amplifier. Because amplifiers are not in as much demand as radios, an amplifier will generally cost more than a radio that has one built-in. You can build your own amplifier. Do a Google search on "audio amplifier" for more information. | ||
| Andrewww |
I have another problem.Tha guy from the electronics store sais there is no such thing as an audio transformer.He sais transformers are only measured in V not in ohms.What should I do? | ||
| Simon Quellen Field (Sfield) |
Find a different person to talk to. Someone who actually knows something. Try doing a Google search for "audio transformer". Then print out the results page and bring it in to the store with you, to show the idiot he is wrong. Or you could just buy the transformer from our catalog. | ||
| Anonymous |
does the FM band beging at 20 MHz? | ||
| Simon Quellen Field (Sfield) |
No. Just look at your FM radio. It starts at 88 Mhz, and goes up to 108 Mhz. | ||
| Alexander N Roberts (Whoo_mythbusters) Member Username: Whoo_mythbusters Post Number: 12 Registered: 9-2005 |
I have an old Radio Shack electronics lab that has a prodject on building an AM transmiter. They dont seem to use a crystal occilator i was wondering what they use to subsitute for this. This kit is called 300 in One Electronic Project Lab Cat. No. 28-270 thanks | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 786 Registered: 12-2004 |
They probably use a resistor and capacitor, or a coil and capacitor, as the tuning element, and a transistor or two as the amplifying element. It will be sensitive to changes in temperature and voltage, and will thus not keep a constant frequency. It will also have many more connections than the simple transmitter I described, since mine has all the transistors and the tuning element all combined in one part. | ||
| Jon Vote (Jon779) New member Username: Jon779 Post Number: 1 Registered: 12-2007 |
Hi - I'm having trouble with the AM Transmitter Kit. The ocilator clearly works fine, but I'm not able to modulate any audio to the signal. I tried using the earphone jack from a radio, a crystal mike, a non-crystal mike, with the transformer, without and the tranformer, reversed the impedance - etc. Nothing works. Any suggestions? Thanks! | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 1815 Registered: 12-2004 |
It sounds like your signal source does not have a low enough impedance to drive the transformer. Find a radio that uses an 8 ohm earphone, and turn the volume up. | ||
| Jon Vote (Jon779) New member Username: Jon779 Post Number: 2 Registered: 12-2007 |
Yes! Using another source did the trick. One more question - I was hoping to set this up so my granddaughter could play DJ. Do you know how I could use this with a microphone? Do I need a pre-amp or something. Thanks! | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 1816 Registered: 12-2004 |
Yes, you will need an amplifier. |
