cwt
Member level 5
balanced modulator
Hi there,
Currently, i have build the modulator and demodulator as shown in Fig.5 and Fig. 29.
The frequency for modulating signal input = 1kHz
Carrier frequency = 100kHz. (for both modulator and demodulator)
The modulator output (either V+ or V-) is able to get the modulated AM output. (However, i only use V- to transmit, V+ i left it as no connection). I use two wires to act as antenna for the modulator and demodulator. By means of wireless transmission, I cant obtained the modulated output from the demodulator. Even if the antenna is very very near. What i obtained is only the carrier signal. But, if i let the two antenna contact with each other, i can get the output and it is same as the modulating signal.
So my doubt is:
i. Is it the length of antenna affecting the transmission?
ii. Is it the transmission power is not sufficient?
Or is there any other factors?
Thanks in advance.
Regards,
cwt
Hi there,
Currently, i have build the modulator and demodulator as shown in Fig.5 and Fig. 29.
The frequency for modulating signal input = 1kHz
Carrier frequency = 100kHz. (for both modulator and demodulator)
The modulator output (either V+ or V-) is able to get the modulated AM output. (However, i only use V- to transmit, V+ i left it as no connection). I use two wires to act as antenna for the modulator and demodulator. By means of wireless transmission, I cant obtained the modulated output from the demodulator. Even if the antenna is very very near. What i obtained is only the carrier signal. But, if i let the two antenna contact with each other, i can get the output and it is same as the modulating signal.
So my doubt is:
i. Is it the length of antenna affecting the transmission?
ii. Is it the transmission power is not sufficient?
Or is there any other factors?
Thanks in advance.
Regards,
cwt