Een LPAM zender met 1 buisje
Het volgende ontwerp is een eenvoudige LPAM zender van een paar honderd milliwatt
Ditmaal eens niet met transistoren maar het oude buizenwerk .
Englisch translation on the page bottem However i'l didt found the time to moderate the translation , so its not gramatical correct
I have used the 80 ECF, PCF or 80 a tube I've
also used a lamp to my receiver
If diet is the diet again be used with the two 12 volt transformer "head to tail" side as in the conscious recipient.
The circuit itself is quite simple, the triode section of the ECF 80 is used as oscillator
the tuned circuit in the cathode grid area, the anode in decoupled to ground via two resistors and gets the power which
d.m.v. a small 10 uf elca additional disconnected penthode The part is used as the final stage and is given the power
from 150 to 200 volts around 300 milli watts carrier issue. The high peak power in the modulation peaks than about 1.2 watts
used with the anode coil wound on a ferrite antenna, it is possible that signal without antenna connected properly in the vicinity
receive, especially on portable radios with a built-in ferrite antenna you can think here of a range of 50 -100 meters.
Go up one extra wire antenna, with an additional winding of wire windings about 100
also on the ferrite wound you with 5 to 6 m antenna length but a range of several kilometers to fetch.
As modulator amplifier is a small computer box used, connect the speaker output of this box (which is normally the connection
to forget the second speaker) to 5 ohms connecting the used modulation transformer and you have enough audio power to
this channel to 100% modulation depth
The oscillator coil is wound with 0.2 mm enamel wire on a 5 mm core, approximately 50 turns
The coil on the antenna beam consists of 40 turns 0.4 mm wire wrapped neatly in a row
For additional antenna coil starting to use again 0.2 mm, an antenna length of 6 m, approximately 100 turns needed
For longer antennas are less number of turns (about 22 winds to 20 m)