[digitalradio] Re: GRUMBLE
You are assuming that speed is what people want. Perhaps that assumption is wrong. 73, --Alex KR1ST http://www.kr1st.com --- In digitalradio@yahoogroups.com, "Simon Brown" <[EMAIL PROTECTED]> wrote: > > Pah! > > Watching 20m PSK at the moment, why do so many users send in uppercase! PSK uses varicode, lowercase is *so* much faster. PSK63 + Uppercase seems to defeat the aims of the game. > > Really it's down to the programmers - let's make the users aware that lowercase is sent much faster. I do this in my Macro Editors. I guess we could add a small option to show the efficiency of the user's input - as-is versus all lowercase. > > FWIW I had a QPSK-125 QSO with RW3DQC - QSO was over before I realised what was happening, he's an excellent operator! > > Simon Brown, HB9DRV >
[digitalradio] Re: Digital Sound Cards -- What IS the best?
--- In digitalradio@yahoogroups.com, "Peter G. Viscarola" < > On the topic of sound cards for digital modes in general: > > While using a sound card with a wide frequency response, > and using high sampling rates, might intuitively appear to be > a good idea, I'd suggest this is not likely to be the case. > > Given that we tend to use the sound card to monitor a radio passband > that's not (likely to be) more than 5KHz wide, sampling much > above the Nyquist frequency for 5K (10K samples/second) seems > counter-productive. The Nyquist (and Shannon!) theorem is often mistunderstood in a manner as demondtrated above. The theorem establishes a *minimum* sampling rate to reliably reconstruct a baseband signal (and not a maximum!). For more on this, see: http://en.wikipedia.org/wiki/Nyquist-Shannon_sampling_theorem A 5khz sinewave sampled at 10 kHz, as mentioned in the example above, will be reconstructed (either in memory to feed applications or to, say, a DAC) as a square wave. At 48 or 96 kHz sampling rate, the resulting representation of the sinewave will look a whole lot more like the original sine wave than the one sampled at 10 kHz. > It seems to me that the key criteria for choosing a sound card for > digital use would be: > > - Flat frequency response from (some low frequency such as) 100HZ to > 5KHZ Every card has this property. > - Dynamic range in the area of 100db (and hence, a very low noise > floor) The noise floor of what? Dynamic range is defined by the sample size, the number of bits per sample. For digitized sound, the dynamic range is 6dB per bit. In order to achieve 100dB dynamic range, you need at least 16 bit samples. > Additionally, it seems like it would probably be a good idea if the > sound card had filtering to remove frequencies below 100Hz and above > 5KHz. There's no need for the sound card to do so. This is already done in the radio. A flat response is not as necessary for a narrow bandwidth mode like PSK31 or CW, but it is beneficial for wide bandwidth modes. People should be much more worried about a flat passband curve of the IF filters than the frequency response of the sound card. The latter is usually extremely flat, while the former is usually not. To see some passband curves you can check out a web page of mine that shows some of these: http://www.kr1st.com/FT897filter.htm If you look at the IC-718 curve you can see that there is easily a 3dB difference between the 1000Hz and 1500Hz. Even though that may not seem much, it is a power difference of 2! If you'd transmit a two tone digital mode at those frequencies then your tones would be seriously out of balance, resulting in perhaps a 15 Watt signal at 1000Hz and 30 Watts at 1500Hz, if no ALC would be present. Since there is an ALC in almost all radios, you actually have to take the response curve of the ALC into account, too. And then we haven't even touched the linearity of the finals So the moral of the story is to worry more about your rig than your soundcard. :-) Whatever you have will probably be fine. 73, --Alex KR1ST http://www.kr1st.com.
[digitalradio] Re: New Software Defined Receiver soon to be available
--- In digitalradio@yahoogroups.com, "Mike/k1eg" <[EMAIL PROTECTED]> wrote: > > Phil this is very interesting. Do you have any figures on sensitivity yet and what's your target price area? Were these questions ever answered, or was there only advertisement? 73, --Alex KR1St http://www.kr1st.com
[digitalradio] Airlink Express version 1.5.1.222 is available for download
Hi there, An update to Airlink Express is now available at: http://www.airlinkexpress.org Version 1.5.1.222 is compatible with USB based soundcard interfaces like the Signalink USB and Digikeyer, and is also made backward compatible with Windows 98 and ME. It also offers many new features: - CAT support for Icom and some Yaesu radios (confirmed: IC-756ProIII, IC-718, IC-275H, FT-897) - Center PassBand (Align) Tuning - RTTY FSK keying through serial port (only through real serial ports) RTS = PTT, TxD = FSK signal - automatic grabbing of callsigns from received text - keyboard shortcuts - clear filters button to the toolbar - auto repeat capability to every macro button - capability to change fonts for the Rx and Tx window - capability to change the background and text color in the Rx and Tx Window - various new macro tags Please read the help file to become familiar with the new features. The installer offers the option to upgrade. If you choose to do so, please make a backup of your log before you upgrade to the latest version. To do this, export the log to an ADIF file (under the File menu option). This will be your backup. Then go ahead and install the latest version with the upgrade option. All macros, settings and the log should be preserved and will be migrated to the new version. I rarely am able to read the Yahoo forums, so please contact me directly if you encounter any problems, have any questions, comments or suggestions. Thank you for your time and 73, --Alex KR1ST http://www.airlinkexpress.org http://www.kr1st.com
[digitalradio] Airlink Express v1.7.1.3 Released
Hi there, I just released version v.1.7.1.3 of Airlink Express: http://www.airlinkexpress.org This version offers the following enhancements: - TX/RX switching through CAT commands for all supported radios (this eliminates the need for a separate comport and interface\ for PTT) - RTS Handshake option for FT-2000/9000/950/450 - CAT support for FT-2000/FT-950/FT-450/FTdx9000 support - CAT support for Elecraft K2 and K3 - CAT support for Kenwood radios - TX/RX window clear button on the toolbar - option to show the tone frequency or actual RF frequency (if CAT is turned on) on the waterfall and spectrum view - checkmark next to the callsign field that will indicate if you have worked a station before, with the option to have the log open automatically and display those prior contacts - partial log export so that you can select which contacts to export to an ADIF file - option to use left, right or both audio channels for input Please see the history page for a complete list of all enhancements, bug fixes, etc. The installer allows you to upgrade from older versions so that almost all settings, macros and log entries will be preserved. However, it is always wise to create a backup of your log through the Export to ADIF function (under the File menu) prior to upgrading the software. Airlink Express is a digital mode software package that is designed for Windows Vista and XP from the ground up, but it will support older versions of Windows, too. The software uses the MMVari DSP engine and is built on the Microsoft .Net 2.0 Framework. For this release the software has been completely rewritten in C#. If you have any questions, suggetions or find any problems, please don't hesitate to contact me directly as I not frequently visit email lists due to time constraints. 73, --Alex KR1ST http://www.kr1st.com http://www.airlinkexpress.org
[digitalradio] Airlink Express Version 1.8.2.57 Available
Hi there, A new version of Airlink Express (v.1.8.2.57) is now available at: http://www.airlinkexpress.org Some of the enhancements in this version are: - true FSK keying for USB to Serial Port Adapters - online callbook data lookup - option to put radio control and PTT switching on the same serial port - parallel port (LPT) PTT support (TRLog type interface required) - support 120 DPI and higher display settings in Windows - option to change the color of transmitted text in the RX window - display UTC date and time in status bar - CAT support for FT-747 Please see the history page on the website for a complete list of all enhancements, bug fixes, etc. The installer allows you to upgrade from older versions so that all settings, macros and log entries will be preserved. However, it is always wise to create a backup of your log prior to upgrading the software. If you have any questions, suggestions or find any problems, please don't hesitate to contact me directly as I am not able to frequently visit email lists and discussion groups. 73, --Alex KR1ST http://www.kr1st.com http://www.airlinkexpress.org
[digitalradio] Airlink Express Version 2.0.1.123 Available
Hi there, Just a quick note to let you know that Airlink Express version 2.0.1.123 is available for download at: http://www.airlinkexpress.org/ This version is compatible with Windows XP, Windows Vista and Windows 7. If you have any questions or suggestions, please contact me directly. I am unable to visit the forums frequently enough to answer questions in a timely manner. 73, --Alex KR1ST http://www.airlinkexpress.org http://www.kr1st.com
[digitalradio] Airlink Express v.2.1.5.378 Released (now with ARQ and PSReporter support)
Hi there, I have released a new version of Airlink Express (v.2.1.5.378) which includes the following enhancements: - PSKReporter (Automatic Propagation Reporter) - ARQ (Automatic Repeat Request); sending and receiving of text and binary files - enhanced support for USB based interfaces and audio devices - Arrow key tuning - Selection of pins for FSK keying - Option to use hardware (UART) timing of FSK for interfaces like the Navigator The latest version can be downloaded at http://www.airlinkexpress.org 73, --Alex KR1ST http://www.kr1st.com http://www.airlinkexpress.org
[digitalradio] Re: Airlink Express v.2.1.5.378 Released (now with ARQ and PSReporter support)
Hi Howard, Yes, ARQ is for file transfer only and it works only between two Airlink Express stations. It's an experimental feature with no intended purpose besides the experiment itself. The protocol is not propriety and is fully explained in the help file with references to original documentation. 73, --Alex KR1ST --- In digitalradio@yahoogroups.com, "W6IDS" wrote: > > Hi Alex, > > The ARQ would be for FILE transfers only and would > have to be Airlink - Airlink normally, in any event, yes? > > Howard W6IDS > Richmond, IN EM79NV > > - Original Message - > From: "whynotbecreative" > To: > Sent: Monday, September 06, 2010 8:01 PM > Subject: [digitalradio] Airlink Express v.2.1.5.378 Released (now with ARQ > and PSReporter support) > > > > Hi there, > > > > I have released a new version of Airlink Express (v.2.1.5.378) which > > includes the following > > > > enhancements: > > > > > > - PSKReporter (Automatic Propagation Reporter) > > - ARQ (Automatic Repeat Request); sending and receiving of text and binary > > files > > - enhanced support for USB based interfaces and audio devices > > - Arrow key tuning > > - Selection of pins for FSK keying > > - Option to use hardware (UART) timing of FSK for interfaces like the > > Navigator > > > > The latest version can be downloaded at http://www.airlinkexpress.org > > > > 73, > > --Alex KR1ST > > http://www.kr1st.com > > http://www.airlinkexpress.org >
