ka9q
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That's correct, my network is multi-homed on IPv6. The 2605:e000 prefix is Spectrum Cable, my ISP. The 2001:470 prefix is a free IPv6-in-IPv4 tunnel provided by Hurricane Electric. Multihoming is a pretty basic feature of IPv6, and every host is re…
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Hi Glenn, long time no hear! jks, thanks for the pointer to the config file. I can probably suggest some other changes, but i want to verify them first. E.g., the US Coast Guard has shut down all of the DGPS reference stations -- not just the DGPS …
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OK, I'm looking at my logs. The problem does indeed seem to be that local IPv6 addresses aren't recognized as local. Here's a sample log entry: Fri Jul 17 06:08:43 01:40:20.525 0123 [05] PWD isLocal_if_ip: FALSE IPv6 remote_ip 2605:e000:1c0e:43f7:d…
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Actually, IPv6 doesn't depend on your ISP doing anything. It doesn't require you to have a router or even an Ethernet switch! That's what the link-local prefix fe80::/16 is for; every host is required to implement it so you will at least have local …
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A server can't necessarily know the DNS name of the client talking to it. To do that it has to take the incoming IP address and perform a reverse DNS lookup, which often fails because people don't bother to maintain reverse records. Also, not every …
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I'm more familiar with North Korean jamming signals (since they're so common, e.g., on 49 and 41m at night when I'm usually listening). From what I've seen of Cuban jamming, which seems different, it's designed to efficiently disrupt AM by concentra…
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Note also that they're 50 Hz low (or they were about 8 hours ago when I last looked). I don't know how well the KiwiSDR DRM decoder tracks frequency errors, so I retuned manually. (Didn't help because the signal was just too poor). It's easy to fin…
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What confused me is that I'd thought you do a right/secondary click by holding down the control key and doing an ordinary click. This seemed to work for most things, but not your program. Now I can calibrate frequency on the KiwiSDRs I run that don'…
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Ah, so that's how you do it! I had it enabled and didn't know it. D'oh!
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Wow, that was fast! Unfortunately I'm on a Mac where it's difficult or impossible to use the right menu, but that's my problem. I need to figure it out anyway. But thanks!
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I have yet to decode Marti on 7345 here in San Diego but that's a combination of propagation, their schedule, and my location. Remember Shannon: channel capacity increases with power and bandwidth Narrower bandwidths put you at a definite disadvan…
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I think the 9 kHz mode has more to do with the 9 kHz broadcast channel spacing in certain countries. In DRM robustness mode B (the most common on HF, as far as I can tell) the OFDM carrier spacing is 46.875 Hz. If the center (nominal) frequency is …
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ha ha ha... :smile:
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"Update: after noting that they were running 9 KHz BW, I pulled the corners of the passband in a tad and got an SNR improvement." But does this actually help? I don't know the details of the DRM decoder implementation and how the displaye…
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China National Radio DRM confirmed in San Diego CA on 7360 kHz at 0645 UTC on Feb 11, 2020. Mode B, 10 kHz, long interleaver, 4QAM SDC, 16QAM MSC, Protect A=1 B=1, Services A=1 D=0. AAC @ 14.56 kbps. UEP 20.7%.
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There's an apparent bug in the inactivity timeout. It doesn't seem to recognize local IPv6 users as local, so it still times them out.
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Excellent. I'll dig into the code and see what I can do. I haven't looked, but I take it that your "native" audio format is 12 kHz PCM, 16 bits/sample? I generally use 48 kHz, but anything that divides it should be easy to use. Re my DRM …
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Here in San Diego, I also see them all over the place (below the MUF, of course). I know that there are some over-the-horizon sea-state chirped radars near here. I suspect there are also some ionospheric sounders.
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DRM has been a real disappointment out here in San Diego. Few stations transmit it, and none of them have been strong enough to decode. Late at night I can regularly see, e.g., China on 6030 kHz or WINB on 7315, but their SNRs are never high enough …
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Has he given a reason for requiring a login? Many websites seem to have done this, or at least added captcha challenges, to defend against high-volume abuse. That might be the case here.
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Has anybody contacted him and asked for a reason? Maybe he was getting abused by non-hams?
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I use Zeroconf to find local devices and services. That's a set of IETF standard protocols that originated as Apple's "Bonjour"; they're especially popular for discovering local printers. The KiwiSDR already runs 'avahi', which is the main…
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Oh yes, doubles are terrible (and totally unnecessary) for DSP even on the x86. I use 32-bit floats for all data samples. Frequencies and quadrature oscillators still use doubles.
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Are you tracking upstream Debian security updates? I consider frequent updates critical to system security, so if we're not supposed to do our own Debian updates then you'll have to take that over.
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I recommend turning off password authentication in SSH if at all possible. In my opinion, this is the single most important thing you can do to secure ANY UNIX-like system on the Internet. Automated password-guessing attacks on SSH servers have been…