91
Equipment / Re: very interesting transceiver
« on: February 18, 2017, 0318 UTC »
Windows 10? I'll stick to my penguin based SDR thank you.
Shortwave Pirate Radio In North America And Around The World, And Other Signals That Go Bump In The Night
We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations.
Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.
That is definitely one way to piss off some people.
redhat is right though, you should use either a zener diode and resistor to regulate voltage going into it or even something as simple as a three leg 5v regulator like a 7805 so that the free running oscillator doesn't drift around.
It's funny because as simple as this circuit looks, this is the one place where engineers start pulling hair because LC oscillators are the most finicky part of a far more complex RF circuit.
Want to get real nasty I recommend a push pull oscillator at half the frequency which runs in anti-phase to get up to the frequency you want to block. Far more stable and will create enough blackout at the frequency if you want to get in some trouble.
In all practicality though wouldn't it be easier to use an FM MP3 player transmitter set to the channel you hate and want to block? Add a piece of wire on the circuit for an external aerial and you're set. Run some fart noises into the audio input to annoy further, and remain somewhat legal doing so.
This was a while back so I should see if the latest version includes our other meters here when I get the chance.
Yeah I guess I was asking how many people would really notice that little of drift or comment on it when logging a station.
I have my own project stabilized down to within 10-20hz drift +/- over an hour total now which is about as good as a VFO can get from everything I have read in ham articles on the subject. This is of course with the heat kicking in and cycling because of winter.
My other question was about how many pirates still use free running VFOs? Seems like everyone I recall logging were probably rock bound or similar but I fell into the category of one of those average people with a basic radio, not someone using a SDR to listen at that time.
Thanks to those cheap $12 TV tuner dongles now I am in that group of people playing with SDRs which is what triggered me to ask this in the first place
Also sorry about that goofy post above, removed it since it wasn't relevant to the thread. Was a long day when I posted it heh.
As I said on the other forum the stability is rock solid with almost any output load on the VFO. Even a direct short to the output has no real consequences to frequency stability. I am willing to bet running the VFO on its own power supply will help even that much more.
Yeah those amazon frequency counters are a steal. I can't believe they only cost $10 with free shipping! They are incredibly accurate and for the price you can pick up a few for various projects. Only issue I had with it is that it came in the mail in a small yellow envelope and was in bubble wrap, no protective box or anything, but it worked right out of the bubble wrap Just make sure to watch the youtube video on how to use the two buttons on the back to set 10/100hz measurement and brightness. The high brightness setting by default is blindingly bright.
They even sell one that can measure up to a few GHz for an extra few bucks.
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92
Shortwave Broadcast / Re: Brother Stair on WBCQ, 9330 kHz
« on: February 03, 2017, 1231 UTC »
What isn't Brother Scare on these days?
93
The RF Workbench / Re: Help with an FM Jammer
« on: December 24, 2016, 1831 UTC »Alternatively, you could modulate the oscillator with a sawtooth waveform which would be more annoying to the 'victim'.Sawtooth through a varactor diode as half the tuning LC circuit to sweep frequencies around the range you desire, nasty thought
That is definitely one way to piss off some people.
redhat is right though, you should use either a zener diode and resistor to regulate voltage going into it or even something as simple as a three leg 5v regulator like a 7805 so that the free running oscillator doesn't drift around.
It's funny because as simple as this circuit looks, this is the one place where engineers start pulling hair because LC oscillators are the most finicky part of a far more complex RF circuit.
Want to get real nasty I recommend a push pull oscillator at half the frequency which runs in anti-phase to get up to the frequency you want to block. Far more stable and will create enough blackout at the frequency if you want to get in some trouble.
In all practicality though wouldn't it be easier to use an FM MP3 player transmitter set to the channel you hate and want to block? Add a piece of wire on the circuit for an external aerial and you're set. Run some fart noises into the audio input to annoy further, and remain somewhat legal doing so.
94
General Radio Discussion / Re: THE SUN HAS GONE COMPLETELY BLANK
« on: June 07, 2016, 2122 UTC »
What's going on in this thread? Where am I?
95
Software / Re: RTLAMR Smart meter monitoring
« on: March 13, 2016, 0647 UTC »I've tried, but not picked up anything. I did some research, and it seems the meters used here (BGE) use a different protocol.I was able to see the water meter usage but the electrical meter here uses a different protocol as well. Interesting piece of software though. Tested it out on Linux using an rtl2832u TV tuner dongle.
This was a while back so I should see if the latest version includes our other meters here when I get the chance.
96
Huh? / Re: Putin hasn't changed his appearance in 100 years
« on: December 18, 2015, 2209 UTC »
Aliens mannn....
97
The RF Workbench / Re: Noticeable drift to listeners
« on: December 05, 2015, 2145 UTC »It sounds like your asking two questions; will people notice, or will it be a problem. The average Joe with an AM detector probably won't notice until the drift exceeds 500Hz or so under good conditions of propagation, he or she will simply notice a change in the perceived audio bandwidth as one edge of the audio sidebands become favored. This is why using a conventional continuous tuning receiver, AM signals sound flat when tuned correctly, and shrill as you tune to either side of the signal. People with AM sync or ECSS detectors won't really notice. Anyone with an SDR, as Chris has shown, will notice any small amount of drift over time, as the software allows you to look at long term trends. We can see when the heat in your place kicked onLol about seeing when the heat kicks in
+-RH
Yeah I guess I was asking how many people would really notice that little of drift or comment on it when logging a station.
I have my own project stabilized down to within 10-20hz drift +/- over an hour total now which is about as good as a VFO can get from everything I have read in ham articles on the subject. This is of course with the heat kicking in and cycling because of winter.
My other question was about how many pirates still use free running VFOs? Seems like everyone I recall logging were probably rock bound or similar but I fell into the category of one of those average people with a basic radio, not someone using a SDR to listen at that time.
Thanks to those cheap $12 TV tuner dongles now I am in that group of people playing with SDRs which is what triggered me to ask this in the first place
Also sorry about that goofy post above, removed it since it wasn't relevant to the thread. Was a long day when I posted it heh.
98
North American Shortwave Pirate / Re: UNID 6930 USB 2333 UTC 11/29/15
« on: November 29, 2015, 2348 UTC »
23:47 ID "You've been listening to ...." microwave oven interference right at the end (thanks person in the other room of the house) 
99
North American Shortwave Pirate / Re: UNID 6930 USB 2333 UTC 11/29/15
« on: November 29, 2015, 2344 UTC »
Weak signal here but definitely audible with the occasional annoying fisher.
Marching/band music 23:40 UTC.
Marching/band music 23:40 UTC.
100
General Radio Discussion / Re: Art Bell terrorised at home
« on: November 27, 2015, 1041 UTC »
Maybe George Noory sent out a hitman because Art is taking away most of his audience?
101
The RF Workbench / Re: Noticeable drift to listeners
« on: November 26, 2015, 0259 UTC »Hi Kage-Thanks for following. Yeah still lots of work to be done considering I am still at the VFO stage and haven't even moved on to the PA and modulator yet which will probably be a separate project, but at least that will be a lot simpler, or at least no where near as time consuming.
I've been watching your ongoing VFO build posts on your forum with great interest. Back in the 80s I occasionally ran a Johnson Valiant from the VFO when I needed to be where I had no rock. I never remember having had negative reports but then again, it was a long time agoWhat Vince said about buffering is true. FMing is a real issue, not only through the RF chain, but by perturbations through the power supply. With the good tight regulation you have with the LM431, that probably isn't an issue. Good luck with the project. BTW- nice pickup on that Amazon counter. Methinks I need one of those...
As I said on the other forum the stability is rock solid with almost any output load on the VFO. Even a direct short to the output has no real consequences to frequency stability. I am willing to bet running the VFO on its own power supply will help even that much more.
Yeah those amazon frequency counters are a steal. I can't believe they only cost $10 with free shipping! They are incredibly accurate and for the price you can pick up a few for various projects. Only issue I had with it is that it came in the mail in a small yellow envelope and was in bubble wrap, no protective box or anything, but it worked right out of the bubble wrap
Just make sure to watch the youtube video on how to use the two buttons on the back to set 10/100hz measurement and brightness. The high brightness setting by default is blindingly bright.They even sell one that can measure up to a few GHz for an extra few bucks.
102
The RF Workbench / Noticeable drift to listeners
« on: November 25, 2015, 1730 UTC »
Just curious if one was to use a VFO for frequency generation how much it would take until it becomes obvious that the station is using a free running VFO?
Is 50hz drift over an hour varying +-25hz occasionally even notable on AM? (currently where I have my circuit zeroed in at, improving a tiny bit each time I try different capacitors)
I realize with SSB this could be an issue fine tuning on the listeners end but with AM I can't imagine this would be of issue correct?
I know there are a few people here who log stations down to 100hz, like 6925.5 for example, but as long as the signal is within a few 10s of hz would that many people even notice?
I worry because I damn near have this VFO built but worry that it will become blatantly obvious that I am using one to some people who are anal about logging frequency and I don't want to be that broadcaster that "drifts".
I know for a fact that pirates of the past used transmitters using VFOs, and it makes me wonder just how much they drifted over an hour or two of broadcasting after a basic warm up. Hell there are even pirates here still using tube based VFOs that broadcast. Those suckers have to drift a ton even when running to specification right?
Can anyone here that did that speak up and admit how much it drifted so?
Is 50hz drift over an hour varying +-25hz occasionally even notable on AM? (currently where I have my circuit zeroed in at, improving a tiny bit each time I try different capacitors)
I realize with SSB this could be an issue fine tuning on the listeners end but with AM I can't imagine this would be of issue correct?
I know there are a few people here who log stations down to 100hz, like 6925.5 for example, but as long as the signal is within a few 10s of hz would that many people even notice?
I worry because I damn near have this VFO built but worry that it will become blatantly obvious that I am using one to some people who are anal about logging frequency and I don't want to be that broadcaster that "drifts".
I know for a fact that pirates of the past used transmitters using VFOs, and it makes me wonder just how much they drifted over an hour or two of broadcasting after a basic warm up. Hell there are even pirates here still using tube based VFOs that broadcast. Those suckers have to drift a ton even when running to specification right?
Can anyone here that did that speak up and admit how much it drifted so?
103
The RF Workbench / Re: LTC1799
« on: November 06, 2015, 0833 UTC »Looks like your're busy over there in .nl.Actually in the US and is a US based forum that is more radio tech orientated. No idea why the site would be blocked. Images are hosted on imgur so maybe that is why.
104
The RF Workbench / Re: LTC1799
« on: November 03, 2015, 0906 UTC »
I absolutely doubt this chip could be used reliably.
For one it has far too much noise so you can expect that clean output to be non-existent and for two if it is controlled by a resistor anything outside of a high quality <%1 tolerance will give you a drift that will cover kHz with temperature change.
I would take a close look at the datasheet. These look quite useful for there intended purpose but as a HF VCO they appear useless from what I have read.
Not to damper your inquiry but I would look into other alternatives.
Nothing beats a real VFO using the proper selection of temperature compensated capacitors with an FET front end and buffer. Problem is that requires some serious engineering to deal with drift compensation which most people don't want to mess with. Alternatives often are the easier choice like a DDS, or PLL, but those also share their own set of problems with spectrum output.
Sadly there is no easy alternative to vibrating a rock, and when you do it requires its own special circuitry outside of a transmitter if you want to do it properly.
Here is a VFO I have been working on with some good success... http://darkliferadio.proboards.com/thread/833/shortwave-vfo-project
I need to update the post but so far I have added proper low pass filtering and a final PA stage to get it up to 100mw output with harmonics down to the floor and no spurs. Harder to achieve that sometimes with a DDS.
Just sharing to give you an idea of the work involved in literally reinventing the wheel. If you have the money and source it is stupidly easy to just go with a quarts crystal.
For one it has far too much noise so you can expect that clean output to be non-existent and for two if it is controlled by a resistor anything outside of a high quality <%1 tolerance will give you a drift that will cover kHz with temperature change.
I would take a close look at the datasheet. These look quite useful for there intended purpose but as a HF VCO they appear useless from what I have read.
Not to damper your inquiry but I would look into other alternatives.
Nothing beats a real VFO using the proper selection of temperature compensated capacitors with an FET front end and buffer. Problem is that requires some serious engineering to deal with drift compensation which most people don't want to mess with. Alternatives often are the easier choice like a DDS, or PLL, but those also share their own set of problems with spectrum output.
Sadly there is no easy alternative to vibrating a rock, and when you do it requires its own special circuitry outside of a transmitter if you want to do it properly.
Here is a VFO I have been working on with some good success... http://darkliferadio.proboards.com/thread/833/shortwave-vfo-project
I need to update the post but so far I have added proper low pass filtering and a final PA stage to get it up to 100mw output with harmonics down to the floor and no spurs. Harder to achieve that sometimes with a DDS.
Just sharing to give you an idea of the work involved in literally reinventing the wheel. If you have the money and source it is stupidly easy to just go with a quarts crystal.
105
General Radio Discussion / Re: Pirate frequency QRM at my QTH: what could it be?
« on: October 29, 2015, 0257 UTC »
Aliens probably, though I have been playing with a VFO but doubt the piss weak 0.020 watt signal on 6925 in a metal box for testing made it your way unless you live 10' from me.
