What Should I Make Next

You may wanna try something along the line of this http://everycircuit.com/circuit/6350493573185536 It's not very simple, but as far as good transmitters go, this is the simplest you could go without resorting to PLL. If done properly the frequency shouldn't deviate a lot. The modulation is being carried out direct into the tuned circuit at the most left. Instead of the 130pF capacitor, you add two varicap diodes anode to anode and two more small capacitors to their cathodes, all in parallel with a 100pF capacitor. At the centre tap of the two diodes, you add a small resistor (3.3k) and choke (1uH) and you introduce some tuning voltage (1-9V). This is where your audio source goes. You should also read in preemphasis of the audio signal before further action.

SSB rig?

Need a linear power amp for SSB

Woah! That is way too complex for me. Maybe FM is still a bit too much for me. Why can't you just design a VCO and modulate the supply rail with the audio signal?

Will this work? http://everycircuit.com/circuit/6651120148807680

SSB is AM mode with carrier wave and one side band removed. Just making a suggestion analog project.

@ the bigger, I have NVIS antenna and 100 watt transmitter. Need more sunspots to bend my HF skywaves down at this time.

@Imccoig, I'm having trouble on how to produce one sideband but not the other. I thought of getting rid of the carrier making it so that one sideband would act as the carrier and the other would be the single side band, but that makes it a frequency doubler which is kind of cool but not very useful. Any ideas on how to make SSB AM? I could technically use an absurdly sharp cutoff filter to remove one sideband but not the other, but that would be impractical and I don't know how to make one without just sticking a bunch of normal filters in series.

I use Software Defined Radio with filters and digital signal processing. My Dad had older CB radio that had upper and lower side band settings. When I get chance I will try to look over early SSB circuits.

I assume you want to make an SSB-SC transmitter, since you're talking about removing the carrier as well. This type of modulation requires a linear type of output amplifier, because the carrier suppression and side band rejection are all made before the signal gets amplified - in one of the first stages. Classically, you should use a balanced mixer to suppress the carrier, and a sharp cut-off filter, to reject one of the sidebands in one of the first stages of your transmitter. Then you need a linear amplifier to upscale the signal, because a class C amplifier can't recreate a suppressed carrier signal.

http://everycircuit.com/circuit/5268981687779328

Try an FM transmitter. It's not that hard. Even a simple VCO, if well shielded, should act nicely. Just add a buffer stage on the output of the VCO.

I already made that particular circuit, just using a Gilbert cell mixer instead of the type your using. My original intent wasn't to eliminate the carrier, it's just that by eliminating the carrier I got the SSB wave shape. I just need a way to either eliminate one sideband or not make that sideband at all. I wasn't actually planning on eliminating the carrier at all.

I am not sure if you can omit any of the sidebands without suppressing the carrier first.

Ok. How can you do it with carrier suppression?

The way I told you, a balanced mixer and a notch filter with specific Q.

Ok. Let's say that I have a balanced mixer creating a 500kHz AM signal without a carrier. What would the notch filter be? I'm not into the technical stuff of electronics, like Q and stuff, I just put components together into a notch filter and fiddle around until I have the right Q or whatever.

A notch filter only responds to a single frequency. Depending on the Q factor the notch filter will have a certain bandwidth you'd need to cover. For instance you have a compressed signal of 8kHz and a suppressed carrier at 500kHz. You'd need the center frequency of your notch filter to be 504kHz and the Q factor of around 60.

Ok, I understand, but won't the quality of removing one sideband but not the other vary depending on the modulating frequency, with 20Hz being the lowest (with the two sidebands being nearly equal in strength) and 4kHz being the highest (with one sideband being at least a ten times stronger than the other if not better)?

I didn't get the question really, sorry

I'm saying that if the two sidebands were at 504kHz and 496kHz, then the upper one would be blocked completely and the lower one blocked only partially if at all, which is good. But if the two sidebands are at any other frequencies, then it won't work as well, and if the sidebands are at 500.02kHz and 499.98kHz (like if the input is 20Hz), then the notch filter will be guaranteed completely 99.98% useless. There must be a better way. Do you know of any such better way?

No, it doesn't work that way. The center frequency of the filter doesn't shift with the bandwidth. The filter would still be centered at 504kHz, and yes, even though 20Hz is somewhat a fringe frequency, the filter should be able to differentiate the lower sideband from the upper one.

Alternatively you can cancel out one sideband by introducing a phase shifted image of the same bandwidth in a mixer.

To me, it seems very questionable that the filter will be able to effectively differentiate between 500.02kHz and 499.98kHz. I'll have to try that phase shift thing.

I can't figure out the phase shift thing, and just when I thought I had it, EC decided it was time to crash. Could you give me a little help?

It won't differentiate these two frequencies, but the receiver also chooses which sideband to use, so suppressing the sideband at the transmitter is mostly done to preserve power.

Phase shift of what?

@thebugger, this is the phase shift I'm talking about. You said it yourself: "Alternatively you can cancel out one sideband by introducing a phase shifted image of the same bandwidth in a mixer." Ok, so if the transmitter doesn't actually have to separate the sidebands, and I can't seem to find a way to decently do that, then I suppose that this conversation is over.

I'm telling you how it's done. The transmitter suppresses the sideband just enough as to not waste much power on it. As far as the receiver is concerned, it chooses one of the sidebands irregardless of the existence of the other. Filters aren't ideal you know, you can't suppress it completely.