#### salvazero

##### Newbie level 4

Hello ,

I'm working on a simple short range AM radio transmitter , and I faced some problems which I hope to find solutions here

1st Problem : I designed 1MHz wein bridge oscillator and it's Pspice model works like a charm . so what is the problem ?? :evil: ... the problem is that I was forced to use the fast AD 745 Op-Amp instead of LM741 :???: and I hope to find a way of making an 1MHz oscillator works with LM741 is it possible ?

Hint : I don't want to use colpitts , Hartley or 555 oscillators !

2nd Problem : I need to multiply the voice signal by the 1MHz carrier ,So I need a multiplier , what is the best way of making a simple multiplier ? , I was thinking of using the logarithmic and anti logarithmic applications of the op-amp but I found it hard and complex process !

3rd Problem : I want to put a High Pass filter to ensure that the dc components is blocked ! , should I apply the HPF on the voice signal or the modulated signal or both of them ? :!:

thx ,best regards :-D :-D

I'm working on a simple short range AM radio transmitter , and I faced some problems which I hope to find solutions here

1st Problem : I designed 1MHz wein bridge oscillator and it's Pspice model works like a charm . so what is the problem ?? :evil: ... the problem is that I was forced to use the fast AD 745 Op-Amp instead of LM741 :???: and I hope to find a way of making an 1MHz oscillator works with LM741 is it possible ?

Hint : I don't want to use colpitts , Hartley or 555 oscillators !

2nd Problem : I need to multiply the voice signal by the 1MHz carrier ,So I need a multiplier , what is the best way of making a simple multiplier ? , I was thinking of using the logarithmic and anti logarithmic applications of the op-amp but I found it hard and complex process !

3rd Problem : I want to put a High Pass filter to ensure that the dc components is blocked ! , should I apply the HPF on the voice signal or the modulated signal or both of them ? :!:

thx ,best regards :-D :-D

Last edited by a moderator: