# Questions tagged [ssb]

Single Side Band - Amplitude Modulated signals transmitted using only one side band, often with suppressed carrier.

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### What would the Signal to noise ratio be for SSB under normally (just) readable conditions?

I want to estimate an upper limit for the data that can be sent over single side band. The upper limit can be determined using Shannon-Hartley theory. The Shannon-Hartley theorem is given by: C = B \...
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### Use of filters for weak SSB when there is no QRM

On bands like 10m when there is often little or no QRM (just gaussian noise), are the "Noise Reduction" filters intended to make weak phone signals more understandable? My subjective view is ...
• 369
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### How can i convert a modulated DSB-SC signal to a SSB-SC signal?

I am designing a simple transmitter using an SI5351A to generate the carrier, then modulating it with a diode ring modulator to generate a dsb-sc signal, then somehow converting it to ssb modulated ...
108 views

### Transfer digital data over ham radio frequencies using QPSK modulation SSB-QPSK transmitter

If I use QPSK modulator/demodulator is it possible to transfer digital data over ham radio frequencies. SSB-QPSK transmitter
• 109
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### How does single sideband work theoretically?

How does single-sideband (SSB) work theoretically? If a theoretical SSB transceiver is a "black box" and only its inputs and outputs can be analyzed, not the way it works internally, what is ...
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### What simple methods are available to test a homebrew SSB transceiver on transmit?

Overview Before putting my recently completed homebrew single conversion 20m mono-bander on the air, I borrowed another radio to listen to the transmission and make sure everything was OK. It turns ...
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### Why is analog TV vestigal side band and not SSB?

Analog TV signals have one sideband cut off to reduce their (very wide) bandwidth and save frequency space in the ether. The lower sideband is cut off, but not completely, the lower 1.25 MHz is kept ...
• 405
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### Do changing sidebands have their own sidebands?

An amplitude changing carrier wave causes sidebands to appear next to it when viewed in the frequency domain. But if those sidebands themselves also change with time (because the modulating signal is ...
• 405
1 vote
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### How does injecting a carrier allow a FM receiver to demodulate SSB?

I just watched VK3YE's video on demodulating SSB using a FM receiver. (https://www.youtube.com/watch?v=kJ-cj-YwflY) In the video, he demonstrates that by transmitting a very weak CW carrier, the FM ...
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### What's the difference between LPF and BPF in context of bandwidth setting?

I'm used to simple RX/TX bandwidth configurations, on my VHF FM rig it's either narrow, normal, or wide. It seems to be much more complex on my new HF SDR rig, and the instructions don't say anything ...
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1 vote
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### Is SSB and FM voice considered TDD or FDD (and what are TDD/FDD)?

We are looking at the Qorvo QPL9547 LNA and the datasheet notes: For TDD Applications: R1 = 0Ω & R2 = 100K For FDD Applications: R2 = 100K ‘OR’ Pin 6 tied to ground. R1 = DNP/Omitted This will ...
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### How to balance a mixer?

I have read about double-balanced mixers and as far as I got the theory right they should suppress carrier frequency. I am trying to build my own transceiver project and I cannot suppress the carrier. ...
• 337
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### SSB Single Conversion Superhet 2nd Mixer IF Termination on Transmit

I have a question about "best practice" in regards to how the 2nd mixer IF port is coupled to (in my case) a 20m double tuned filter on transmit. I'm currently building out the transmit ...
• 989
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### What is the etiquette for answering real world, non-contest HF SSB calls?

I'm a new ham (licensed back in the spring) and very new to HF (only a couple of weeks). One thing I've noticed in the phone bands is that things seem to rarely go the way all the articles aimed at ...
• 1,027
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### HF SSB etiquette when someone is working quick but not contesting and you're not sure they got you?

When someone is working quickly -- clearly trying to work a lot of stations -- but pretty clearly isn't contesting, what's the etiquette when they 73 you and end the contact but you're not sure they ...
• 1,027
769 views

### What's the realistic SSB reception range for 25W on 20m and 40m?

Because of my living situation I am using a Par EndFedz Mk II Trail Friendly antenna with my IC-7300, since it can do 40m and 20m and is only 41 feet long. However, it can only handle 25W. Now, for ...
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I'm learning about shortwave listening. I want to listen to amateur/ham radio on a portable radio (eg a XHDATA d-808) with SSB, I hear SSB is the main place hams would be on. I know it's hard to give ...
9k views

### What does ALC do on a transceiver?

What is ALC on an HF transceiver? What are the disadvantages (if any) of operating using a rig without ALC? What might be the difference between a good and bad implementation of ALC?
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### SSB Transceiver Architecture - USB with Crystal Filter

I'm planning to build a 20m SSB transceiver and I want to get the overall architecture straight in my head first. Here's what I'm thinking so far, a single conversion superhet design with a 9MHz IF ...
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1 vote
491 views

### How can I check if my CB radio is AM or AM/SSB?

How can I check if my CB radio is AM or AM/SSB? I know that it is a CB UHF radio but there is no information of whether it is AM or AM/SSB.
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### Where can I find a table listing the maximum PEP per band?

I'm building myself an Excel Cheat Sheet.
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### Does the output of a BFO for a short wave receiver have to be exactly a sine wave?

I want to build an external beat frequency oscillator (BFO) for an old valve Eddystone receiver I have. There are many circuits for BFOs on the internet, they are mostly similar, the idea seems simple ...
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1 vote
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### LSB modulation and demodulation

A USB signal is basically a baseband signal shifted up in frequency. However, an LSB signal is the mirror image of a baseband signal then shifted up in frequency. How is this 'mirroring' modulation ...
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### Combining two CFU455IT +/-2kHz (4kHz) ceramic filters to get a +/-1.25kHz (2.5kHz) filter for SSB

Can I put two of these cheap (less than 3USD) and common CFU455IT +/-2kHz (4kHz bandwith -6dB ) ceramic filters in series to get a lower bandwidth good for SSB TX? If I'm correct I will get -12dB at +/...
1 vote
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### What are the practical differences between the different voice modes (and why aren't there any SSB Handheld Transceivers (HT's))?

It's my understanding that FM is used for UHF, VHF, and SSB is generally reserved for other bands. From my understanding, FM better audio quality when reception is good SSB: more efficient (can ...
255 views

### How can i adjust the IF strip in a single conversion SSB receiver which has a product detector?

I have an analog 27 MHz transceiver which i am planning to convert to 10 m. The radio is an AM / SSB unit with a single conversion superhet receiver with an IF of 7.8 MHz using a crystal filter. This ...
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### Is there a way to get FreeDV output level to follow the input audio amplitude?

I'm using a commonly available imbedded firmware implementation of FreeDV with an SSB HF transceiver. It seems that FreeDV encodes the input audio signal in both the frequency and time domains, ...
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### Can a carrier operated relay be used for T/R switching in a HF linear amplifier?

I am building the T/R switching circuit for an HF linear amplifier covering 80m band to 20m band. The current circuit takes a potential-free contact from the exciter and use this contact to turn on/...
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1 vote
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### How to calculate VFO/IFO frequencies?

I am trying to build a simple superhet receiver for listening SSB signals. I read several articles about SSB and got confused so I am looking for some practical explanation. I have 2 mixers, quartz ...
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### Required SSB sideband and carrier suppression?

Is there a legal (U.S. FCC) or a commonly accepted standard requirement for SSB opposite sideband and and carrier suppression for either manufactured or kit built transmitters? Does the 43+ dB down ...
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1 vote
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### Raspberry Pi rpitx for SSB with filter?

Using rpitx, we can transmit SSB using a single GPIO port from the Raspberry Pi. This of course uses square waves so creates a lot of harmonics. If I were to use a ...
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### Effect of frequency division on a signal's spectrum [closed]

I am constantly on the lookout for effective yet inexpensive means to generate SSB signals. Analog Devices' LTC5598 Direct Quadrature Modulator turns baseband analog I/Q signals into RF from 5MHz to 1....
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### How does signal strength relate to bandwidth?

Let's say I have a 25 W transmitter. First I transmit some SSB signal with 2500 Hz bandwidth (no audio compressor is used, etc...). Then I transmit a BPSK31 signal with at most 100 Hz bandwidth using ...
1 vote
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### ICOM IC-910h How much bandwidth does it listen when receiving USB and FM?

CD-audio has a bandwidth of 22kHz. CW usually has a bandwidth between 3 to 5 kHz. But I am wondering what is the bandwidth my Icom IC-910H can listen to in both, the SSB and the FM mode? Also, what ...
1 vote
430 views

### Is it possible to transmit and receive FSK G3RUH using SSB transceiver operating on USB-D?

Can a generic SSB transceiver, together with an FSK modem, be used to receive FSK modulated digital signals? If so, what considerations should be taken? and what kind of issues (AGC? Compression? ...
2k views

### Why does a Class-C non-linear power amp distort SSB but does not distort AM?

Can someone tell me why exactly a transistor non-linear power amplifier will amplify an AM signal without noticeable distortion, but will distort an SSB signal, giving the familiar scratchy sound ...
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### Is it legal to transmit scrambled or encrypted voice via SSB on ham bands?

And also, can anyone tell me how? Using Arduino or any other way ...
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### What exactly is a "balanced modulator"?

While studying for his U.S. General class license, my son wondered about the "balanced modulator" referred to by a few questions in the FCC pool. Quoting KB6NU's General Class study guide to give a ...
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### Can an SSB transmitter be used to transmit PSK?

Can a generic/typical analog SSB transmitter be used to send PSK modulated digital signals? If so, how does that work? How is a computer or DSP interfaced with an SSB transmitter? Line level ...
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### SSB filtering in the frequency domain?

I'm not sure whether it's more appropriate to ask this question here, or in the dsp.stackexchange. But I'll try here first. There seems to be a lot of information available on the filtering and ...
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### SDR (RTL-SDR v3) USB audio much less than LSB

Why does USB have so much less audio output than LSB? I've checked all settings and they are correctly set or not used, like AGC etc. Using same band pass on both modes.
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### How does this circuit work? Why is the antenna connected to the output of the amplification stage?

What is the function of the configuration of R1, C3,C10 and R3? How does the LC tank in this circuit work?
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### SSB offset determination?

Is there any algorithmic way to determine if the mixed frequency offset in an SSB SDR demodulator is wrong (too high or low), other than listening for funny sounding voices? (perhaps by checking to ...
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1 vote
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### SDR demodulation of SSB

Is there any difference between demodulating LSB versus USB in software from IQ samples other setting the complex mixer frequency (LO) below or above the SSB signal frequency? (and excluding any ...
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### Single Side Band AM vs FM

I know the difference between AM and FM, but could anyone explain to me what is the differences between single side band AM and conventional FM? So far as I know the SSB modulation will reduce the ...
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### WSPR RX dial frequency

I tried but failed to decode WSPR using Tecsun PL-600 receiver that tunes in 1KHz step. I heard tones with good SNR but cannot be decoded. So, I mis-set it somewhere. Is it correct that transmission ...
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### SSB Modulation and Differential Signaling

I'm trying to learn about how SSB modulation works. My current understanding from reading and looking at spectrum plots from SDR software is that the sound is modulated with the carrier, but only ...
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### SSB Generation. 4th method?

The mode of SSB is alive and well. It has relevance for long-distance comms and does not waste spectrum. The orthodox methods of generation are Filter, Phasing and Weaver. These methods can be and are ...
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### In SSB how do receivers calculate the frequency offset without a carrier?

On page 2-9 of the ARRL Ham Radio License Manual, it discusses how in SSB one of the side bands and the carrier are suppressed to conserve power and bandwidth. Given the explanation of how AM works, ...
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