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About borjam

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    Bilbaina Jazz Club
  • Interested in Sound for Picture

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  1. Anything Ethernet based is so flexible. You can even use fiber instead of twisted pair. It’s much thinner and depending on the type of transceivers and fiber you use it can run for several Km while twisted pair is limited to 100 m.
  2. The main difference between the two antenna types is bandwidth. Log-periodic antennas are useful over a much wider range of frequencies. That’s the reason, I imagine, why the so called shark fin antennas are so popular for radio mics.
  3. I would say he is in Spain, gathering swift sounds for a sound background. (Several Spanish productions feature really conspicuous swift sounds, which is actually a nice detail because they are really loud in Spring and Summer)
  4. Wow, just got an email from Sound Devices announcing firmware version 7 and an additional feature for the II Series: A Noise Assist plugin at $300. Previously it was MixAssist. So, I guess MixPres are doubling as an entry level hook for the Sound Devices "drug"
  5. But a RTL dongle lacks the analog filters before the ADC present in a real spectrum analyzer. As far as I know RF Explorer is a ˝classic" spectrum analyzer with a mixer and a sweeping local oscillator. That configuration improves the dynamic range. No matter how good your digital domain filtering is, if the ADC gets overloaded, game over
  6. I understand that it's fun, but beware: All of the computer based SDR software I have tried is fiddly. And I own three more serious SDR units. You know better than me how expensive shooting time is The worst problem with a RTL used as a test instrument is, however, dependability. These units don't have very good front end filtering, and in the presence of strong out of bands signals they might show ghosts that would not be a problem for properly filtered wireless equipment. So, using something like the RF Explorer is more dependable and predictable. RTLs are great for tasks such as software development tasks because being what is now called a "real time spectrum analyzer" you can observe very fast digital transmission bursts. Also, spectrum analyzers like the RF Explorer tend to have software options better suited for this task (like building a curve with maximum peaks) while SDR programs for computers are better suited for radio listening. There are some spectrum analyzer applications but, as I said, most of that software is not production ready. If it works for you, great! But please be aware of its limitations.
  7. No I didn't, as the kludge worked for me and I haven't had much time to go outdoors and recording this Spring 😕 I'll do it this week, after all being confined at home...
  8. It's just reducing probability. Someone with mild symptoms can have some fever.
  9. borjam

    Jay Rose

    Oh I am really sorry! I only exchanged a message or two with him but it was clear to me how knowledgeable he was, how generous sharing his knowledge and what a gifted technical writer he was. My condolences.
  10. The NeXT Cube I have at home has a 450 MB hard disk. That was a huge disk in the late 80's And I remember back in 1991 we ordered a couple of 750 MB disks from the USA. Large Maxtor drives weighting a ton, the interface was SCSI probably. I think they were $2500 each. At that time it was worth ordering directly from abroad, in Spain prices for this stuff could be 2x or even 3x.
  11. At high sound pressure levels ultrasounds can produce audible sounds when colliding with objects. The transition between different mediums (air and a solid body) creates a non linear effect. For example, it is possible to beam an AM modulated towards a wall. The beam will be demodulated and the modulating signal will be heard like it originated from a spot on the wall. https://en.wikipedia.org/wiki/Sound_from_ultrasound I have seen it working, a friend was experimenting with this some time ago. I guess it will provoke a similar phenomenon on the microphone diaphragm.
  12. There's no menu option. You can switch the spectrum view between modes by pressing the [Return] key (user manual, page 17). if you see SP (span, ie, the frequency range shown on screen), C (center frequency) and RBW on the bottom of the screen, you are in advanced mode. For example the screenshot shared by Michiel is in advanced mode.
  13. (I am not affiliated with them, just curious about the outcome!) Austrian Audio, the company created by former AKG staff "made redundant" when Samsung acquired Harman Group, has announced two headphone models. An over-the-ear (Hi-X55) and and on-ear (Hi-X50). https://austrian.audio/hi-x55/ https://austrian.audio/hi-x50/ The prices I've seen announced by the British distributor are 249 pounds for the Hi-X55 and 199 pounds for the Hi-X50. Both models feature detachable cables and they claim robust construction with metal hinges, etc.
  14. An advantage of using a SDR receiver, be it a cheap RTL or something more expensive like a SDRPlay (or Airspy) is that the SDR work as "real time spectrum analyzers" while the RF Explorer and others (like my Siglent SVA1000X) are classical sweeping analyzers. The difference is: A sweeping analyzer is not monitoring the whole SPAN bandwidth simultaneously, but sweeping a receiver over the frequency range and sampling amplitudes. So there is a chance that a very quick burst may be missed. Of course if you leave it in peak hold mode and have it running for several minutes the detection probability will be high. A real time analyzer, however, samples a whole chunk of spectrum (1 MHz or so for the RTL, 8 or 10 MHz or so for the SDRPlay and the Airspy) and calculates a Fourier transform, which means it is sampling the SPAN at once. So even really short bursts can be made visible. But the disadvantages of using a SDR are too many. You need more equipment (computer), SPAN is limited unless you buy a really expensive one (10 MHz or less) and complexity skyrockets because you need SDR software running on the computer. And at least all of the SDR software I know is a royal p.i.t.a. so unusable in a demanding situation like a shot or stage where you need to focus 200% on everything else. On the other hand, if anyone is considering a full RTA, it would be a huge overkill and the minimum prices are in the thousands of dollars. Such units are useful for people who design digital communications equipment, especially if doing bursty transmissions.
  15. I'm glad it worked. Regarding the vanishing permissions, the advantage of operating systems with a Unix heritage is that very few paranormal phenomena occur, if any! So yes, it was trivial to predict that one Now, I'll check later what spell you need to make that change permanent. I am not familiar at all with Ubuntu, so I have to dig a bit. It will involve editing a configuration file. Do you feel comfortable doing that? It's a simple task but Unix text editors can be a bit daunting to inexperienced users! And no problem at all for the technical support thing. I'm happy to contribute to this forum. Besides, I guess it will be useful for other users. Turning an old, cheap computer into a large spectrum analyzer screen is great
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