dk8ok.orgNils Schiffhauer – DK8OK | HF – All you can eat from zero to 30 MHz.

Nils Schiffhauer – DK8OK HF – All you can eat from zero to 30 MHz. Search for: Menu About Stations Aero Airborne Modes FSK-2 170 Hz / 228,65 Bd [ALIS, RS-ARQ, GM857, GM2000, MERLIN] 1.000 Hz / 500 Bd [CIS Burst] MFSK PSK MPSK / OFDM RADAR / Ionosondes JORN – Australia MISC [CW, FAX, Chirp, Beacons …] Impressum Datenschutz RX-888: 32 MHz/16bit, 200 US-$ – pricks up your ears Posted on September 4, 2020 by DK8OK 17 comments The RX-888 covers 32MHz @16Bit in a row. Here it comes to life with Simon Brown’s unique and indispensable software SDRC V3 at an professional active dipole antenna MD300DX . It is the (a few weeks) younger brother to the RX-666, a brainchild of Oscar Steila, IK1XPV . And it is one of the first palm-sized SDRs in the price class of 200 US-$ which covers the whole HF band for receiving, recording and playing with 16Bit resolution, resulting in a competitive dynamic range of about 100dB. I got one from China via eBay (there are numerous sellers) within a few days. Overnight, Simon, G4ELI, made his SDRC V3 software to match also to the RX-888 with excellence. You need a PC, an i5 should do it, with USB3.0 for data streaming, controlling and power supply. Yes, there is no need for a separate 5 or 12VDC! Much had been speculated about one obvious fact: the price of the A/D chip is, if only a medium order is placed, the same or even higher than the price tag at the RX-888. How comes? One rumor with some substantial background results in this story: the chips had been desoldered from boards of other projects which didn’t pass the quality control. These boards had been sold at a low price as a bonanza to smart people who can use all the parts which on their own will have passed the quality control, most notably the pivotal A/D chip. This blog should give you a first impression. The biggest difference between RX-666 and RX-888 seems to be that the latter is equipped with a permanent low-noise amplifier of +20dB which perfectly balances sensitivity and dynamic range for 90% of us DXers. The range from 32MHz to ca. 1.8GHz is covered with up to 8MHz/8bit only (R820T2 chip). Sensitivity on HF is nearly on par with FDM-S2. Two antenna sockets – the impressive cooling fins on three sides of the box will be needed after a planned update of covering 64 MHz in a row with 16Bit, and up to 10MHz (now: 8MHz) above 64MHz. I tested the RX-888 from 10kHz to 32MHz and had a look above 32MHz – see the two following screenshots. RJH69 on VLF 25.0kHz. This time signal from Belarus was received at 07:06 UTC on 02SEP2020 in Northern Germany and read with CW decoder MRP40. A look onto 8MHz of the FM broadcast band. The RX-888 also worky nicely together with decoders like DRM or (other) data, see the two following screenshots. The very weak DRM signal of China National Radio on 9655kHz [Urumqui, 30kW, antenna direction 98°!] is duly received by the RX-888 with the data decoded with free DREAM software. US Air Force Diego Garcia [JDG] in the Indian Ocean calling their Lajes counterpart [PLA] in the Açores on 4721kHz at 17:18UTC in MIL-STD-188-141A. PC power: Nowadays, a “receiver” is a system, consisting of an SDR (the box), software and the PC. While world-class software SDRC V3 is for free, and an top SDR costs just about 200 US-$, you should not forget an able PC. It must be an i5 and up if you want to digest bigger bandwidth like 8 MHz, 16 MHz or even 32MHz. Even for recording 32 MHz, there is no need for internal SSDs, a fast iron disk will do the job. Furthermore: 32MHz recording for 24 hours do expect a bit more than 11TB disk space. This calls for an external HD, and a second USB3.0 card (not: hub!) is a must. As external HD, I use the WD MyBook Duo, delivering 28TB at under 750 US-$. The combination of an desktop i7 and this HD ensures stutter-free recording and playing up to bandwidth of at least 32MHz. Here simply more is more … Last, but not least, please find below a few audio examples of broadcast as well as utility stations. They proof that the RX-888 is a serious receiver at a ridiculous low price. 4712 kHz/USB: Russian Airports with radio checks in Russian: Kazan, Rostov (net control), Saratov, Samara, Novosibirsk, Chelayabinsk. They transmit with 1kW of power to a low-hanging dipole. 02SEP2020, 17:00 UTC. 4750kHz/AM-ECSS: Bangladesh Betar with ID over an obviously defective transmitter (nominal 100kW). 02SEP2020, 17:00UTC. 4800kHz/AM-SAM: Chinese National Radio Beijing I (Geermu, 100kW) ID in Mandarin, ID. 02SEP2020, 22:00 UTC. 4920kHz/AM: Tibet People’s Broadcasting Station (Lhasa, 100kW), ID in Tibetan. 02SEP2020, 21:00 UTC. 5000kHz/CW: Chinese Time Signal Station BPM (Sha’anxi/Pucheng, 5kW), ID in CW. 02SEP2020, 22:00UTC. 6676kHz/USB: Singapore VOLMET, 5kW, ID and weather in English. 02SEP2020, 17:20UTC. 6676kHz/USB: Bangkok VOLMET, 5kW, ID and weather in English. 02SEP2020, 18:10UTC. 7240kHz/AM: Tibet People’s Broadcasting Station (Lhasa, 100kW), ID in Mandarin. 02SEP2020, 21:00 UTC. 9275kHz/AM: FEBC Philippines/Bocaue (100kW), ID in Mandarin. 02SEP2020, 14:00 UTC. 9310kHz/AM: VoA Deewa Radio (Udon Thani/Thailand, 250kHz), ID in Pashtun/Urdu. 02SEP2020, 14:00UTC. 9664,77kHz/LSB: Radio Voz Missionaria (Camboriu/Brazil, 10kW), ID in Portuguese. 02SEP2020, 22:00UTC. 10’000kHz/CW: Chinese Time Signal Station BPM (Sha’anxi/Pucheng, 5kW), ID in CW. 02SEP2020, 17:00UTC. SDR RX-888: 32 MHz, 16 bit – A new standard SDR for HF Posted on September 3, 2020 by DK8OK 7 comments A bare sensation: the RX-888 covers 9 kHz to 32 MHz with 16 bit (nearly 100 dB dynamic range) with recording and playing the whole range via USB3.0 which also cares for the power supply. Price: just about 200 US-$. With the RX-888 just has arrived here, I am busy with testing. The first results a very much encouraging with Simon Brown’s (G4ELI) unique software SDRC V3 . More to come within a few days. SDR Switching-on HF Transmitters: Step by step Posted on August 24, 2020 by DK8OK One comment Voice of Turkey, Emirler, signing on: 9880 kHz, The ABB transmitter SK5SC3-2P is switched to full poer [500kW] in five steps within about three seconds. Recently, I came across the different sign-on ceremonies of different transmitters. The idea is to understand this workflow in which obviously several stages of the transmitter are switched on consecutively. See at the top one example, where Voice of Turkey is swithcing on their transmitter on 9880kHz in five steps within about three seconds. The diagram was made with Simon Brown’s unique software SDRC V3 . I used the Signals Analyser module, providing a (needed!) time resolution of down to just one millisecond, or 1000 values of level vs. frequency in just one second! These data (CSV) had been exported and visualized in QtiPlot software . I would like to encourage other people to join these observations. One goal can be toi fingerprint no only a transmitter, but also the workflow of the people at the transmitter. Please refer to this website for a database of broadcasters and their transmitters plus galore of associated data. In the meantime, I already observed a couple of different workflows/transmitters. Please keep in mind that all these measurements (better: estimations), of course, are prone to fading. You may also see some effects during sign-on in the spectrogram, see below. Radio Saudi, signing on, 17’615kHz at 12:57 UTC on 02APR2020. You clearly see at least three different steps of power plus some transient when switiching to full power. Broadcast SDR Software RX-666: Listen to A Gamechanger! Posted on August 7, 2020 by DK8OK 23 comments Flying high: RX-666 Since Marco Polo, combinations of Italian and Chinese had proven fruitful. The Dragonfly RX-666 is such a combination or, at least, a very special “kind of”. It is a 16bit SDR, ranging 1 kHz to 30 MHz in a row with 16 bit resolution – plus some extra above 32MHz (1.5/1.7GHz) by the help of an R820T2-chip of RTL-SDR fame, but 8 bit only. Priced not much over US-$ 200 (if that) at...