Help me build a SSB modulator

[epilot]

Hello there,

i want to build a SSB modulator to modulate a carrier at 40kHz with an audio,

what the best choise is please?

it has to be SSB so i am not sure if i can find something to make a SSB or i have to make a circuit as AM or DSB and then use from filters to remove part of band?

sorry i am new in the modulation and need for help.

Thanks

 

[biff44]

Re: AM

Here is how you do it at higher frequencies:

**broken link removed**

I imagine you can do a similar thing at 40 KHz with op amps and analog multipliers. The box with the "X" in it in the center is a 0/180 degree hybrid, which can be done with 2 op amps of gain 1 and -1. The 0/90 degree splitter can be done with a resistive splitter and a 90 degree LC phase lag circuit (or an RC op amp circuit). Mixers (circles with the "X"s in them) can be analog multipliers. Power combiner at output can be one summing op amp.

 

[epilot]

Re: AM

Here is how you do it at higher frequencies:

h**p://www.polyphasemicrowave.com/pages/single-sideband_modulator.html

I imagine you can do a similar thing at 40 KHz with op amps and analog multipliers. The box with the "X" in it in the center is a 0/180 degree hybrid, which can be done with 2 op amps of gain 1 and -1. The 0/90 degree splitter can be done with a resistive splitter and a 90 degree LC phase lag circuit (or an RC op amp circuit). Mixers (circles with the "X"s in them) can be analog multipliers. Power combiner at output can be one summing op amp.

but i want to build one with a modulator chip i don't want a commercial one(i am not sure about the chip number but there must be something to produce SSB)?

 

[biff44]

Re: AM

I am unaware of any "commercial" uses for a 40 KHz carrier!

 

[epilot]

Re: AM

finally i used MC1496 balanced modulator chip to get a DSB on the output(pin 6 or 12)
there is a small problem, i have a small part of unmodulated input signal on the out put of the chip, that is because the chip is not very perfect,

can someone help me to remove that small signal from the output please?

since the chip is a balanced modulator and has 2 output ithink it is possible using an OP AMP or a coil with a tap.

any idea would be appreciated.