This is pretty self explanatory from the image above. Top section of the waterfall is the NooElec “Distill:FM” FM notch filter and the bottom section is a 75dB rejection FM notch that preserves Airband. I bought the bottom filter from GPIO Labs on eBay. I thought at first that the NooElec filter was doing an OK job for what it was, but it’s just not that great. If you’re not near any close FM stations or have a station that’s on the edge of being annoying, feel free free to chance on the NooElec, but the GPIO labs is at least 40dBfs (SDR# measurements may not be scientifically accurate) better at almost entirely removing FM broadcast. The station at 94.9Mhz above is KUOW which is a 100KW flamethrower not 1/4 mile from me. It images my RTLSDR and wrecks havoc everywhere. Even with the NooElec in line, I get imaging everywhere and can’t turn the gain up much on the RTLSDR. With the GPIO labs I can easily max out my RTL gain on FM and have KUOW do absolutely no imaging. At full gain I can’t even get a pilot tone out of KUOW to grab stereo information with the GPIO labs filter.
GPIO Labs also sells an even better 85dB rejection FM notch filter if you don’t mind losing Airband. Pass on the NooElec if you’re serious about needing proper FM rejection. I’ve bought many of their products and they’re all disappointing except for their new TCXO 0.5ppm RTLSDR’s. NooElec needs to up their game, because most of what they offer isn’t exactly good and isn’t exactly hard to build. If you don’t mind spending the extra $10, I’d go for the GPIO labs. I’d also recommend the official RTL-SDR.com FM notch. There are plenty of videos of it being tested with proper lab equipment and what it claims is exactly what it does.
*These tests were done with the same RTLSDR dongle, with the same SDR# settings, same gain settings, and same antenna. Nothing was moved, nothing was re-positioned and I was sitting in the same spot.
Knowledge Zenith [KZ] is known for quality low cost Chinese audio gear; mostly in-ear-monitors, and rarely lets down at their price points. For between $4-$35 KZ has made it possible to get a great sounding IEM without breaking the bank. KZ had the ZST, ATR, and ZS3 in 2016 as their former ‘flagship’ IEM’s, but in May 2017 they brought the 2BA + 2DD four driver ZS5’s to the market. There has been some recent controversy that shows KZ may be cheating with the ZS5’s, claiming a 4 driver setup, but only providing port holes for sound to exit into the ear with only two of the drivers. Unfortunately it has not been verified by a third party yet, but as the second batch of pre-orders finally start arriving we should then see some tear downs from some more trusted members of the community.
The international version of the ZS5 comes in the standard KZ packaging that most everyone who has owned KZ IEM’s in the past knows. The Chinese version of the packaging is much more elegant and premium. Inside the box you receive:
I noticed Chrome started displaying in Material Design few months ago on a few Android news websites, but had to do some digging with weird keywords to actually figure out how to do this. It brings more Material Design elements into your website and creates a more imersive enviornment when looking at the page. This also works to easily distinguish your website from other tabs in the Lollipop multitasking menu. (more…)
Cheap (<$100) vaporizers that actually work correctly are very hard to come by, but I have been looking at reviews on subreddits (/r/vaporents) for some time now and I finally made up my mind and ordered a Magic Flight Launch Box. I ordered the cheapest version to give it a test run. There are multiple wood types and multiple patterns to engrave onto the top window, but anything aside from the base MFLB will cost you extra. At $76, this is one of the cheapest real vaporizers on the market. Aroma-Tek managed to get it here in one day for free! (more…)
I decided to have some fun and build my own down converter for my Raspberry Pi. On my first try I used a LM7805 but quickly realized it would not work with 14V and the TO-220 heatsink I had on hand. I saw some videos on the cheap Amazon/Chinese/eBay voltage down converters, and I really wasn’t impressed. They looked poorly made with copied LM2596’s and are probably very noisy, which isn’t good for my radios. I wanted quality and efficiency to use my Raspberry Pi on batteries, so with a few dollars worth of quality parts I managed to throw my own DC-DC step down converter together with the circuit design direct from Texas Instruments above. (more…)
I needed to buy a safe to lock up some of my expensive medication that had been stolen in the past. I set out to find a digital safe because I didn’t always have my keys with me, and I am very bad at remembering combinations and which way to turn the dial. There aren’t many cheaper/smaller safes now that aren’t digital. Some even have a credit card type system! I browsed around, glanced over reviews, and eventually found the Bunker Hill Security 0.71 Cu. Ft. safe at Harbor Freight for a little under $50 with a 20% off coupon that Harbor Freight usually puts on their website. This was the cheapest digital safe with the most amount of space that I could find. After installing it in my room, and putting my pills and some other belongings in it, I started to wonder why my pills were still going missing a week later. After reading reviews in depth and watching Youtube videos, I found out that this safe was not actually safe. (more…)
Just a few days ago I bought a Raspberry Pi with nothing but the case and SD card expecting to just have it run as a little SSH server so I could remotely login to my weechat tmux instance, and upload weather data to wunderground from my weather station with weewx. I set everything up, tinkered around with it for a day or two and had it running smooth. I got curious and had heard in the past that the Raspberry Pi could be turned into a low power FM radio. Reading further, the Raspberry Pi actually does 1-250Mhz which is a perfect range for amateur radio operators. I knew it wouldn’t provide much power (10 dBm), so weak signal modes were what I needed. (more…)
I have only 8 months Linux experience under my belt, but I now run Mint 16 and Mint 17 as daily drivers on my desktop and laptop. Here are my first impressions of Mint 17 “Qiana” using my hardware.
After trying the Mint 17 RC installer a few weeks ago on my Asus Zenbook UX301, I ran into a big problem when installing it. Grub couldn’t read the partition map from /dev/sda and errored out of the installer. I gave up trying and installed Mint 16 again flawlessly. Seeing a post last night on /r/linux about the official release of Mint 17 prompted me to give the Mint 17 install another chance on my laptop. I opted for the Cinnamon version to test its new Retina/HiDPI support with my 13″ 2560×1440 screen. (more…)
Hello World! I am currently unsure what this blog is going to be for. I think it may be a mix up between politics, news, amateur radio, linux, computer hardware, makeup, cryptocurrencies, and probably touching on some LGBT issues. We’ll see where this windy road takes me.