SSB Carrier Supression

[Nigel Goodwin]

Post the schematic of your audio amp from the detector diode to the speaker and we will show you where the noise comes from.

Why bother, he won't listen anyway

 

[audioguru]

Why bother, he won't listen anyway

But this circuit is new.
It has many class-A noise generators.
It has lousy old 741 opamp noise generators.

If we can show him how to eliminate the noise in his audio amplifier then he can widen the bandwidth so we can hear what the voices are saying.

Then we can find out why the frequency of the BFO wanders all over the place and fix it.

Then he will have a really good radio.

 

[flat5]

I played with the audio file.

 

[flat5]

I've got a list of parts to buy that I will send to Futurlec.

Want to see it and make suggestions?

 

[audioguru]

I played with the audio file.

My wife asked why am I listening to beeps and whistles?
I said they were people talking but she couldn't understand what they were saying. I also couldn't understand what they were saying but I heard one guy say, "Yeah" then "coffee now".

I made a suppressed carrier SSB for a telephone voice scrambler with an MC1496 modulator IC and made a demodulator circuit almost the same. The demodulated voices sounded absolutely perfect, not beeps and whistles.

 

[flat5]

It's one of the parts I'm ordering from Futurlec.
I used it in the receiver I made 30 years ago.
I was lucky to have a Collins 2.7khz mechanical filter at the time.
Audio was quite clear. Used a LM380 to drive a speaker but often listened with headphones.

 

[Mikebits]

but watch out, they will take shots at you in the process.

I don't recall ever taking shots at you. I do feel however, that telling others that I do this, is a shot at me.

I do not recall making disparaging remarks to others about you. I do remember suggesting to you, that you should be more willing to open yourself to other thoughts and ideas when it comes to improving your radio. I am sorry to hear you think I take shots. Ok, I do take a shot of whiskey from time to time.

 

[Space Varmint]

I've got a list of parts to buy that I will send to Futurlec.

Want to see it and make suggestions?

See what I mean?

I knew that would make them go ballistic...lol.

Yeah let's see the parts.

 

[Space Varmint]

I don't recall ever taking shots at you. I do feel however, that telling others that I do this, is a shot at me.

I do not recall making disparaging remarks to others about you. I do remember suggesting to you, that you should be more willing to open yourself to other thoughts and ideas when it comes to improving your radio. I am sorry to hear you think I take shots. Ok, I do take a shot of whiskey from time to time.

Actually I said you were one of the guys that knew their stuff.

Man, had a good time last night. Got me 3 CW QSOs. Haven't done that in a while.

 

[Mikebits]

Actually I said you were one of the guys that knew their stuff.

Man, had a good time last night. Got me 3 CW QSOs. Haven't done that in a while.

That does sound like fun. All I got last night was laid.

Ok, maybe that was a shot...

 

[Space Varmint]

The reason I said what I said about the Xtal filters is because....

Where the hell did these ladder networks come from???

I've seen these filter that got like 14 Xtals for their selectivity. I mean, you just don't need that many. Two is good and maybe a third, but Iv'e seen them 5 & up in these ladder networks.

 

[Space Varmint]

That does sound like fun. All I got last night was laid.

Ok, maybe that was a shot...

Ah hell, even that gets old after a while. Then you got to get back to the real ****....radio my man! That's the ticket

 

[Mikebits]

Ah hell, even that gets old after a while. Then you got to get back to the real ****....radio my man! That's the ticket

Umm, well either I don't know how to listen to radio, or you don't know how to... well, this is a family show

 

[Space Varmint]

Umm, well either I don't know how to listen to radio, or you don't know how to... well, this is a family show

Oh, here come the shots.

Dude, I'm sorry it bothers you that I can sit hear listen to a couple of french dudes talking down around 7.100 MHz with no problem on the home brew.

It's just that way. Too late to do anything about it.

 

[Mikebits]

Oh, here come the shots.

Dude, I'm sorry it bothers you that I can sit hear listen to a couple of french dudes talking down around 7.100 MHz with no problem on the home brew.
It's just that way. Too late to do anything about it.

You really are sensitive. Don't you know when someone is just having good natured humor with you? Just joking with ya for petes sake.

 

[Mikebits]

Oh, here come the shots.

Dude, I'm sorry it bothers you that I can sit hear listen to a couple of french dudes talking down around 7.100 MHz with no problem on the home brew.

It's just that way. Too late to do anything about it.

You speak French? Impressive...

7 Meg band. I figured a little higher would be much quieter for noise.

 

[Space Varmint]

You speak French? Impressive...

7 Meg band. I figured a little higher would be much quieter for noise.

Again, are you a ham? 36 years here buddy. Higher freqs? If there were any sun spot activity in recent history, maybe so but it is not a question of noise. It is a question of ionospheric bounce or propagation. If there had been good solar activity then it is possible at the higher freqs to get some contacts (QSOs) on 5 watts from the other side of the world through sporadic E.

 

[Space Varmint]

Your 80m recording sounds awful like ducks quacking beside a loud waterfall. The BFO sounds like its frequency changes with the incoming signal level.

My audio spectrum analyser is not calibrated but it shows the voices have no low frequencies and no high frequencies. The noise is wideband and continuous so I think it comes from your audio amplifier circuit.

Post the schematic of your audio amp from the detector diode to the speaker and we will show you where the noise comes from.

Quack Quack

 

[Space Varmint]

It's one of the parts I'm ordering from Futurlec.
I used it in the receiver I made 30 years ago.
I was lucky to have a Collins 2.7khz mechanical filter at the time.
Audio was quite clear. Used a LM380 to drive a speaker but often listened with headphones.

Hey buddy! Didn't see you there. You guys could take a lesson in manners from this fine gentleman ^^^^^

I got an old Collins mechanical filter somewhere for 455 KHz. Actually I don't use sharp filters in the 2nd IF so I can shift the frequency a little. Your radio is the 1st mixer. I'll talk about it more if you like but yeah I played with the LM380 & the LM386. When a really weak station came through I really had to strain to hear it. You should try that chip audioguru recommended, the TDA2822. It absolutely cleared up any of that nonsense. It has enough drive to where you can afford to back down some of your audio driving stages so that not any one stage is doing too much amplification, thereby practically eliminating the possibility of clipping provided you have ample AGC.

 

[flat5]

Audio is easy. At least for a ham receiver. Osc. and mixers are more of a problem for me, I think.

Thank you SV for letting me post a parts wanted list in your thread.
Hope it turns out to be useful, for me

Darn! I can't upload an attachment!? So here it is:

inductors (which?)
------------------------------------------------------------------------------
toroid cores (which?)
Amidon FT-37-43's (tank circuits and transformers)
T-37-02 or T-80-06 (For oscillators and filters)
"I usually use the number 2 & number 6 mix such as where (T) is toroid and (80)
would be the size parameter for .8 inches diamter and (6) is the powdered iron
mix. The designator (FT) means ferrite toroid"
Amidon minimum order $10
------------------------------------------------------------------------------
coil wire (what sizes?)
small trimmer caps
air var caps
matched diodes on chip
AA battery holders (2 cell, 4 cell)
9v battery clips
------------------------------------------------------------------------------
Futurlec components
===================
Basic 3.5 Digit Multimeter with Temperature Measurement
BREADBRD (Breadboard 174mm x 67mm)
PROTO777 (Prototyping Board 116x96mm)
STPBRD2 (Stripboard - Small 94x53mm)
EXPBRD (Experimenters Board 120x80mm)
STOFFHEX_10MM (10mm M3 Hexagonal Standoff w/screws)
Red Crocodile Clips - Small
Black Crocodile Clips - Small
Red Crocodile Clips - Medium
Black Crocodile Clips - Medium
2mm Test Probes for Multimeters
SPST10 (SPST on-off Miniature Toggle Switch)
DPDT11 (DPDT on-on Miniature Toggle Switch)
HEADS8 (8 Pin .100" Straight Male Headers)
HEAT1MM5BLUE (1.5mm Heatshrink Tubing - Blue)
HEAT2MM5YELLOW (2.5mm Heatshrink Tubing - Yellow)
HEAT3MM0GREEN (3.0mm Heatshrink Tubing - Green)
HEAT5MM0RED (5.0mm Heatshrink Tubing - Red)
9V Battery Clip (Standard 9V Battery Clip with Flying Leads)
IND1000 (1,000uH Inductor)
IND10000 (10,000uH Inductor)
TRIM2K (2K 1/4W Min. Horizontal Pot)
TRIM10K (10K 1/4W Min. Horizontal Pot)
TRIM50K (50K 1/4W Min. Horizontal Pot)
TRIM100K (100K 1/4W Min. Horizontal Pot)
POT10KA (10K Logarithmic Taper Pot)
POT50K (50K Linear Taper Pot)
CRY10.245 (xtal 10.7mhz to .455mhz)
CRY8.000 (8mhz to make bandpass filter)
OSC8.000 (osc module)
RESON8M0 (8.0MHz Ceramic Resonator)
LED3R (Red 3mm Round LED)
LED3G (Green 3mm Round LED)
LED3Y (Yellow 3mm Round LED)
LED3RG (Red-Green 3mm Round LED)
LED5R (Red 5mm Round LED)
LED5G (Green 5mm Round LED)
LED5Y (Yellow 5mm Round LED)
LED5RG (Red-Green 5mm Round LED)
BZX79-C5V1 (5.1V 500mW Zener Diode)
BZX79-C6V2 (6.2V 500mW Zener Diode)
BZX79-C9V1 (9.1V 500mW Zener Diode)
1N34A (Germanium Diode)
1N4148 (100V 200mA General Purpose)
1N4004 (400V 1A General Purpose)
1N4007 (1000V 1A General Purpose)
1N4937 (600V 1A Fast Recovery Diode)
MPS2222A (NPN General Purpose)
PN2907A (PNP General Purpose)
MPF102 (MPF102 JFET N Channel)
78L05 5V Positive Regulator (100mA)
78L08 8V Positive Regulator (100mA)
78L09 9V Positive Regulator (100mA)
78L12 12V Positive Regulator (100mA)
NE602 (mixer-osc low level only, easy to overload mixer)
LM1496 (bal mod&demod)
ULN2204A (radio)
CA3086 (npn transistors)
LM555
LMC555 (cmos timer, low power)
LM386N (250mw 6v (min) audio)
LM380N (2watt audio)
TDA2822 (One Watt Stereo or two watt bridge Amp IC)
TL074CN (low noise quad op amp)
TL072CP (low noise dual op amp)
TL071CP (low noise op amp)