946
Huh? / Re: It's about that time...
« on: October 05, 2016, 1805 UTC »
I don't think that's the kind of hurricane that the NWS was warning us about 
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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 permissable in your locale.
Neighborhood going to hell Joe?
This thread got of topic in a hurry
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And let the brainwashing and self-hating begin!
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947
The RF Workbench / Re: The death of DIY receiver building (the loss of discrete baseband components)
« on: September 29, 2016, 0649 UTC »
In this particular application group delay is important because it can screw up the crosstalk between I and Q in the stereo quadrature demodulation process so filters with optimized GDT are nice. Fortunately most digital modulation methods also get cranky over group delay, so a lot of the filter designs over the last 20 years or so were designed with this in mind.
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948
The RF Workbench / Re: The death of DIY receiver building (the loss of discrete baseband components)
« on: September 28, 2016, 2131 UTC »
There appears to be a similar problem with this option as well. The Token datasheets lists parts I could use, but there are no distributors listed, and the ones I can find are not in usable bandwidths. I am looking for +/- 3, 5, 10, and 15 KHz. The 15 KHz filters are actually 30 KHz wide and will be used as a roofing filter at the front of the IF chain, with smaller filters used in front of the demodulator.
*edit* after some searching on Token's website, it looks like they will sell in small quantities to individuals. Might be worth a try.
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*edit* after some searching on Token's website, it looks like they will sell in small quantities to individuals. Might be worth a try.
+-RH
949
The RF Workbench / The death of DIY receiver building (the loss of discrete baseband components)
« on: September 27, 2016, 2139 UTC »
Several years ago I had the idea to build a small stereo HF receiver based around some then available parts. I was working on the design for this a week or so ago and when I went to my part vendors, I noticed that most of the 455 KHz IF filters made by Murata and others have been either slated for, or outright discontinued. Whatever vendor stock is out there appears to be all that will ever be, as even a sweep through ebay reveals very little in the way of options.
What is an RF hobbyist to do? The world has gone to DSP, and most of the development kits for these thing exceed the mean income of most of the residents of Detroit (Sorry, had to do it). Nevermind that most of these solutions draw too much power for battery applications.
Anyone have any leads on these things?
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What is an RF hobbyist to do? The world has gone to DSP, and most of the development kits for these thing exceed the mean income of most of the residents of Detroit (Sorry, had to do it). Nevermind that most of these solutions draw too much power for battery applications.
Anyone have any leads on these things?
+-RH
950
North American Shortwave Pirate / Re: XFM 6875/6870 AM 0112 UTC 24 Sep 2016
« on: September 24, 2016, 0118 UTC »
Thanks for the note, we moved down 5 KHz, hopefully with less QRM.
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951
General Radio Discussion / Re: AT&T Promises Gigabit Speeds Using Existing Power Lines
« on: September 21, 2016, 1548 UTC »"To that end, we’re looking at the right global location to trial this new technology next year.”
If the antennas could be disguised to look like plastic grocery store bags or pairs of sneakers with their laces tied together, then this would not be obtrusive in my neighborhood. Just sayin'.
Neighborhood going to hell Joe?
This thread got of topic in a hurry
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952
General Radio Discussion / Re: AT&T Promises Gigabit Speeds Using Existing Power Lines
« on: September 21, 2016, 1347 UTC »
I don't know why telecoms insist on reinventing the wheel. Fiber works and works well, lets roll out what we know works, rather than some bench pipe dream that needs, you guessed it, more spectrum.
Man I'm getting cynical in my old age
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Man I'm getting cynical in my old age
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953
Huh? / Re: Transmitting SSTV over WBFM (wideband FM)
« on: September 20, 2016, 1208 UTC »
It should work fine over a telephone too, but you'd have to get the average dumbass to care, which surveying the FM audience anywhere in this country isn't very likely.
Just my 2 cents...
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Just my 2 cents...
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954
The RF Workbench / Re: A legal limit am transmitter for 75/160 meters from WO1U
« on: September 19, 2016, 1056 UTC »
Number one; your dealing with a crowd that values simplicity. I agree, PWM is the way to go, but there is something to be said for simplicity. My back says otherwise
Number two; I was reminded of this when Antenna was mentioning all the trouble his friend had with modulating that kit rig, and some of the same problems I think this guy who wrote the paper discovered as well.
In this day and age, people are still building grenade clones, not because of their 'superior design and quality'...quite the opposite. There is a lot to be said for something that can be made and repaired from commonly available parts, and that is where the desire to build these things comes from. Its just another way to approach the problem.
*edit* upon further reflection, it could also be that the preference toward high level transformer modulation relates to nostalgia. To a lot of the older guys, unless it 'feels' solid with lots of iron, like big cars, it just doesn't feel right. Heavy iron may be reminiscent of old broadcast rigs. Just a thought...
All the best,
+-RH
Number two; I was reminded of this when Antenna was mentioning all the trouble his friend had with modulating that kit rig, and some of the same problems I think this guy who wrote the paper discovered as well.
In this day and age, people are still building grenade clones, not because of their 'superior design and quality'...quite the opposite. There is a lot to be said for something that can be made and repaired from commonly available parts, and that is where the desire to build these things comes from. Its just another way to approach the problem.
*edit* upon further reflection, it could also be that the preference toward high level transformer modulation relates to nostalgia. To a lot of the older guys, unless it 'feels' solid with lots of iron, like big cars, it just doesn't feel right. Heavy iron may be reminiscent of old broadcast rigs. Just a thought...
All the best,
+-RH
955
The RF Workbench / A legal limit am transmitter for 75/160 meters from WO1U
« on: September 18, 2016, 2022 UTC »
I found this ages ago when researching what others were doing in the realm of class D on HF. A google search for '75 meter am transmitter paper pdf' will get you the original from the AM Phone message board.
This has some neat practical information for those of you who want to experiment with high power levels and high level modulation. His prototype will make 1500W PEP on 75 or 160 Meters (3.8 and 1.8 MHz respectively) at over 90% efficiency. It also covers some of the pitfalls of this method.
This is not a call to action, but some practical info from someone who has done it. With the drive system and fets in use, I doubt this would survive an excursion to 43 meters, but the same principles apply.
http://amfone.net/Amforum/index.php?action=dlattach;topic=30798.0;attach=31360
+-RH
This has some neat practical information for those of you who want to experiment with high power levels and high level modulation. His prototype will make 1500W PEP on 75 or 160 Meters (3.8 and 1.8 MHz respectively) at over 90% efficiency. It also covers some of the pitfalls of this method.
This is not a call to action, but some practical info from someone who has done it. With the drive system and fets in use, I doubt this would survive an excursion to 43 meters, but the same principles apply.
http://amfone.net/Amforum/index.php?action=dlattach;topic=30798.0;attach=31360
+-RH
956
North American Shortwave Pirate / Re: X-FM 6975 USB 0051 UTC 9/18/16
« on: September 18, 2016, 1014 UTC »
Not I, but Thank You for the relay!
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957
Software / Re: Amalgamated DGPS Software
« on: September 17, 2016, 0520 UTC »
So is the software smart enough to triangulate your receive location based on receive timing, et al, or do you tell it where you are?
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958
General Radio Discussion / Re: K263AP is missing its tower
« on: September 17, 2016, 0513 UTC »
About ten years ago when the scrap prices of copper started going up, AM stations all over the country were noticing an increase in metal theft, usually from their ground systems. The price of the scrap was far outweighed by the replacement costs, especially for directional stations. Some went dark.
On the FM side of things, transmission line theft has been more of a problem with cable spools sitting around than cable in service. Even though, aluminum hardline is becoming more common despite its seemingly higher rate of failure.
damn crack heads...
+-RH
On the FM side of things, transmission line theft has been more of a problem with cable spools sitting around than cable in service. Even though, aluminum hardline is becoming more common despite its seemingly higher rate of failure.
damn crack heads...
+-RH
959
HF Mystery Signals / Re: mystery sig. 6.945
« on: September 16, 2016, 1310 UTC »
I noticed this over last weekend too. Strange waveform.
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960
General Radio Discussion / Re: KIFM is building a transmitter in Nevada
« on: September 12, 2016, 2207 UTC »...so they can hear the Gospel and be discipled by the teaching. Every person in the world must hear the end-time message of “Get ready for the coming of the Lord” and Revival!
And let the brainwashing and self-hating begin!
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