| From: | Mark McLaughlin <mmclaugh@*******.EENG.DCU.IE> |
|---|---|
| Subject: | Electronic/Radio Geniuses |
| Date: | Thu, 20 Feb 1997 12:56:12 -0800 |
reply please do so via private mail.>
If any of you are good at electronics especially radio/transmitter
electronics could you please explain the following schematic to me.
It is a simple transmitter/Bug and I would like to know as much about
how it works as possible.
Required Parts
--------------
(1) 2n3904 transistor............................[Q1]
(1) 10k resistor (+-5%)..........................[R1]
(1) 4.7k resistor (+-5%).........................[R2]
(1) 1k resistor (+-5%)...........................[R3]
(1) .001 uf capacitor............................[C1]
(1) 5 to 80 pf variable capacitor................[C2]
(1) 10 pf capacitor..............................[C3]
(2) .5 uh coils..................................[L1,L2]
(1) SpSt slide switch............................[S1]
(1) 9 volt battery clip..........................[B1]
(1) Antenna or antenna wire (3 in. or more)......[A1]
(1) microphone (like one out of a phone).........[M1]
Schematics
----------
--------------*-------------*-------------*-------------*
| | | | |
| | | | |
+A1
| | | | L1 |
S1 R1 | C2 | |
| | | | *----
| | | | |
+ | | | L2
B1 | | | |
- | C1 | |
| | | | |
| *-------------*------Q1/----*-------------*
| | \ |
--------* | \_________________C3
mike | |
--------* | |
| R2 R3
| | |
| | |
---------------------------------------------------------
Furthermore, is it a bad sign when a red type of dye seemed to leak from
the middle leg of a variably capacitor. (I thought it was the dialectric
but a friend of mine said that it was probably OK.)
Mark McL
