[digitalradio] SignaLinkUSB freq response and S/N
Has anyone else tried to characterize the SignaLinkUSB frequency response and S/N properties? I Have, and, to put it mildly, I'm underwhelmed. Compared to my old homebrew interface combined with an aged SoundBlaster16 PCI it sucks as far as pure data is concerned (I have spectralab dumps to document my statements; if anyone are interested mail me directly) The real interesting question here is: how important is this in real life? Both interfaces work fine doing everyday PSK31, RTTY, SSTV etc, but how critical does it become when working signals near the detection limit as in WSJT JT65, FSK441 and very weak HF PSK31? Why not just continue with the old setup? well, my new LapTop doesn't have serial ports and my radio (FT-847) no VOX; I do need more than one Soundcard, and I need something that'll work with Linux. All in all the SignaLinkUSB sounded attractive judged from reviews and blurbs -- Vy 73 de OZ1PIF/5Q2M, Peter ** CW: Who? Me? You must be joking!! ** email: peter(no-spam-filler)@frenning.dk http://www.frenning.dk/oz1pif.htm Ph. +45 4619 3239 Snailmail: Peter Frenning Ternevej 23 DK-4130 Viby Sj. Denmark ***
Re: [digitalradio] RTTY WAS 5 needed
On Wed, Sep 3, 2008 at 12:58 AM, Dave Cole [EMAIL PROTECTED] wrote: I can do Oregon for you... Thanks Dave, any suggested day/time for a sked?
RE: [digitalradio] SignaLinkUSB freq response and S/N
QUOTE The real interesting question here is: how important is this in real life? Both interfaces work fine doing everyday PSK31, RTTY, SSTV etc, but how critical does it become when working signals near the detection limit as in WSJT JT65, FSK441 and very weak HF PSK31? /QUOTE This is something I've been thinking about for a long time. Remember that we use the sound card as an A/D converter. Thus the overall frequency response beyond whatever is necessary to digitize the desired bandwidth is at best unused, and at worst capable of creating spurious signals in within our band of interest. It MIGHT be that a soundcard with limited bandwidth might be BETTER for our needs. Now, in terms of S/N ratio... I find it hard to believe that quieter isn't better no matter how you look at it. Peter K1PGV
Re: [digitalradio] SignaLinkUSB freq response and S/N
On Wed, Sep 3, 2008 at 6:11 AM, Peter G. Viscarola [EMAIL PROTECTED] wrote: Now, in terms of S/N ratio... I find it hard to believe that quieter isn't better no matter how you look at it. But at what point does it become insignificant? I've heard of people using low-noise preamps on antennas, but never low-noise audio amplifiers. (Is this because we compress the signal with the RF and AF gain controls?) Is the quest for low noise audio cards the equivalent of seeking gold-plated, oxygen-free, 10 gauge speaker wire for our rigs? This should be a straightforward math question for a rig designer. But I'm not a rig designer. Anyone know?
Re: [digitalradio] SignaLinkUSB freq response and S/N
--- On Wed, 9/3/08, Russell Hltn [EMAIL PROTECTED] wrote: From: Russell Hltn [EMAIL PROTECTED] Subject: Re: [digitalradio] SignaLinkUSB freq response and S/N To: digitalradio@yahoogroups.com Date: Wednesday, September 3, 2008, 1:29 PM On Wed, Sep 3, 2008 at 6:11 AM, Peter G. Viscarola [EMAIL PROTECTED] wrote: Now, in terms of S/N ratio... I find it hard to believe that quieter isn't better no matter how you look at it. But at what point does it become insignificant? I've heard of people using low-noise preamps on antennas, but never low-noise audio amplifiers. (Is this because we compress the signal with the RF and AF gain controls?) Is the quest for low noise audio cards the equivalent of seeking gold-plated, oxygen-free, 10 Guage speaker wire for our rigs? This should be a straightforward math question for a rig designer. But I'm not a rig designer. Anyone know? The noise induced by all the stages from the antenna to the speaker play a part in the overall noise figure or noise factor.A long run of coax can have noise to add even though it is a passive component and not an active device. There is a long drawn out formula to determine the overall noise factor. Hopefully the first stage or two is low enough and has enough gain to override the following devices such as the mixer, IF and AF amps of the receiver. Low noise stages in the audio will help, but you night not notice the help. Sort of like if you have a truck load of bricks and add one more brick. You know it is there, but it takes some special weighing equipment to notice it. The driver of the truck would not know you added it by the way the truck drives. Here is a link to the formula. http://en.wikipedia.org/wiki/Noise_figure In very low noise systems (say less than 2 or 3 dB )even the noise in the coax is the limiting factor and not the loss of the coax. No mater how much gain you have , you can not pull a signal out that is less (maybe much less) than the noise without special equipment. A well designed system will balance the gain and noise factors of each stage. For the low bands usually there is usually enough atmospheric, man made and other noise that a very low noise figure is not needed. Even the antenna will see enough of the earth to limit the signal to noise ratio. You see number of around 270 deg K as the average temperature. The antenna will pick that up due to the heat of the earth. By having a good beam that is pointed above the earth such as a satellite dish , the antenna noise will go down and preamps in the 30 to 60 deg K will work. I am sure the oxygen free, gold plated #10 guage speaker wires will help, but it is like a fly landing on that brick truck. Maybe more like the fly on the brick truck taking in a breath of air.
[digitalradio] Re: SignaLinkUSB freq response and S/N
Peter Frenning [OZ1PIF] skrev: Has anyone else tried to characterize the SignaLinkUSB frequency response and S/N properties? . I'll not repeat my my message here, just indicate which message it's about. I have been accused of damaging Tigertronics reputation and possibly their business with my statements. If indeed so, it was not my intention, and I sincerely apologize. My questions are still valid (even if my data are bogus, in which case I need to learn why), and I hope to get to the bottom of this. The fact still remains that my particular combination of Radio, Interface and computer, put together as recommended by the manufacturer, does exhibit a data transfer which does, on the evidence of my data, have some disturbing characteristics. Whether this is even significant, due to my errors or faulty equipment remains to be determined. I will report back to the groups, when I'm in the clear with this. -- Vy 73 de OZ1PIF/5Q2M, Peter ** CW: Who? Me? You must be joking!! ** email: peter(no-spam-filler)@frenning.dk http://www.frenning.dk/oz1pif.htm Ph. +45 4619 3239 Snailmail: Peter Frenning Ternevej 23 DK-4130 Viby Sj. Denmark ***
Re: [digitalradio] Re: SignaLinkUSB freq response and S/N
I might suggest looking at some discussions that were recently held on this subject on the illinoisdigitalham yahoogroup. The group originally was for a specific geographic area but now is a general digital radio type forum and allows discussion of digital related issues. 73, Rick, KV9U Peter Frenning [OZ1PIF] wrote: Peter Frenning [OZ1PIF] skrev: Has anyone else tried to characterize the SignaLinkUSB frequency response and S/N properties? . I'll not repeat my my message here, just indicate which message it's about. I have been accused of damaging Tigertronics reputation and possibly their business with my statements. If indeed so, it was not my intention, and I sincerely apologize. My questions are still valid (even if my data are bogus, in which case I need to learn why), and I hope to get to the bottom of this. The fact still remains that my particular combination of Radio, Interface and computer, put together as recommended by the manufacturer, does exhibit a data transfer which does, on the evidence of my data, have some disturbing characteristics. Whether this is even significant, due to my errors or faulty equipment remains to be determined. I will report back to the groups, when I'm in the clear with this. -- Vy 73 de OZ1PIF/5Q2M, Peter ** CW: Who? Me? You must be joking!! ** email: peter(no-spam-filler)@frenning.dk http://www.frenning.dk/oz1pif.htm Ph. +45 4619 3239 Snailmail: Peter Frenning Ternevej 23 DK-4130 Viby Sj. Denmark *** No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.6.15/1649 - Release Date: 9/3/2008 7:15 AM
Re: [digitalradio] Re: SignaLinkUSB freq response and S/N
My signalink usb measures +- 1db from 200hz to 5khz. I did not try to measure outside this range since I consider it irrelevant for digital. The s/n measures 73db over the same range with 20db of headroom. Tom K6TGT Peter Frenning [OZ1PIF] skrev: Has anyone else tried to characterize the SignaLinkUSB frequency response and S/N properties?
Re: [digitalradio] SignaLink USB Interface Reviewed in Popular Communiations, September 2008
Mark Thompson wrote: http://www.popular-communications.com/PC%20Highlights%20Sept%2008.html TECH SHOWCASE The SignaLink USB Interface—A Plug-And-Play Solution For Digital Communications Modes by John Kasupski, KC2HMZ Anyone who has experimented with receiving digital format signals by radio has undoubtedly experienced one or more of the difficulties that typically arise when you set out to decode digital signals using a radio and computer. Your sound card is incompatible with your software, or you don’t want it tied up doing digital decoding. You have more than one radio you want to use and don’t want to have to buy or build separate interfaces for each. Or perhaps you just don’t want to pay a fortune for all the software you need in order to decode the numerous digital modes that exist (with new ones seemingly being invented daily). If this is the situation you’ve found yourself in, you’ll find this article to be just what the doctor ordered. Earlier this year, I purchased a SignaLink USB interface (Photo A) from Tigertronics in Grants Pass, Oregon. This device, which costs less than some of the competing commercially available radio/computer interfaces ($104.95 if ordered with a cable to fit Kenwood and ICOM radios using a 13-pin DIN accessory port; $99.95 for everybody else), not only interfaces your computer to any radio, it also contains its own built-in USB sound card. That means that the sound card already in your computer is left free for whatever else you want to do with it. How It Works And What You Get The SignaLink USB connects to your computer’s USB port and is powered from the USB port so that no external power source is needed. All the necessary cables come with the device, including the USB cable, the cable to interface the SignaLink USB to your radio, and a mono cable to connect to radios that don’t have receive audio on the mic or accessory jack. Additional cables can be ordered if you have more than one radio and they don’t use the same cable. The mono cable can be used to connect the SignaLink USB to an external speaker jack on a scanner or shortwave receiver, or if using a transceiver, the connection is made using the radio cable. This can be accomplished using a connection to a 4-pin round, 8-pin round, RJ-11, or RJ-45 mic connector, or you may instead order the radio cable to connect to a data or accessory port that uses a 5-pin DIN, 8-pin DIN, 13-pin DIN, or 6-pin mini-DIN connector. An un-terminated cable for radios that use a different type of connector is also available in case you have an unusual situation, such as wanting to build a cable for a handheld radio. Also included with the device is a set of jumper wires that simply push into a socket on the SignaLink USB’s circuit board. A software CD is also included with the device and contains jumper settings for the most popular radios. Settings for other radios can be determined by following the procedure in the included manual, or by contacting the Tigertronics tech support staff. To read the entire article, subscribe to Popular Communications http://unix8.sunserver.com/cq/Search.bok?category=Popular+Communications+Subscription+NEW+or+RENEWAL Digital Ham Group http://groups.yahoo.com/group/illinoisdigitalham/ I am sorta hesitant to enter this thread, so I will simply make the suggestion that the noise in the original post is not noise, but rather it is interference, i.e. signals caused by the electronics in the unit and not from external sources. Please excuse this interruption Chuck AA5J Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] What Is A Good FLARQ Frequency?
Hello, I have flarq running here and would like to give it a try. Anybody out there want to suggest a good frequency? Rick - KH2DF/W5
Re: [digitalradio] Re: SignaLinkUSB freq response and S/N
If you use a big shovel you will eventually dig up something bad. So ask yourself this, does the product work? Does the product do what it is intended to do? Does the product stay within parameters that are expectable within rules? I was making my decision between Tigertronics or Rigblaster. I looked at all the comments that are out there. I then made my decision of the lesser concern. The wait time is a drawback and I have heard it is not rugged, I tend to be a little harder on my equipment then others, but I still went with the TigerTronics. I will be happy to provide my opinion when the unit actually shows up.. James KB7TBT NEGARC Activities Manager www.kb7tbt.com www.ne4ga.org www.myspace.com/kb7tbt - Original My questions are still valid (even if my data are bogus, in which case I need to learn why), and I hope to get to the bottom of this. The fact still remains that my particular combination of Radio, Interface and computer, put together as recommended by the manufacturer, does exhibit a data transfer which does, on the evidence of my data, have some disturbing characteristics. Whether this is even significant, due to my errors or faulty equipment remains to be determined. I will report back to the groups, when I'm in the clear with this. --
Re: [digitalradio] What Is A Good FLARQ Frequency?
14073 , 7073 On Wed, Sep 3, 2008 at 9:13 PM, Rick Westerfield [EMAIL PROTECTED] wrote: Hello, I have flarq running here and would like to give it a try. Anybody out there want to suggest a good frequency? Rick - KH2DF/W5 -- Andy K3UK
Re: [digitalradio] What Is A Good FLARQ Frequency?
On two meters, we use 144.144 around 1500 Hz using DominoEx 11. On HF, we use 3584 around 1500 Hz, and MFSK16. 73, Skip KH6TY NBEMS Development Team I have flarq running here and would like to give it a try. Anybody out there want to suggest a good frequency? Rick - KH2DF/W5
RE: [digitalradio] What Is A Good FLARQ Frequency?
I am listening on 7.073 at 01:31z Fred VE3FAL -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of kh6ty Sent: Wednesday, September 03, 2008 9:17 PM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] What Is A Good FLARQ Frequency? On two meters, we use 144.144 around 1500 Hz using DominoEx 11. On HF, we use 3584 around 1500 Hz, and MFSK16. 73, Skip KH6TY NBEMS Development Team I have flarq running here and would like to give it a try. Anybody out there want to suggest a good frequency? Rick - KH2DF/W5 Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links
Re: [digitalradio] What Is A Good FLARQ Frequency?
On Wed, Sep 3, 2008 at 9:32 PM, Fred VE3FAL [EMAIL PROTECTED] wrote: I am listening on 7.073 at 01:31z Fred VE3FAL Tnx for the try Fred, maybe we are too close. here is an example of the copy using MFSK16 7l} t0otetRa K3UK DE VE3FAL THANKS FOR THE TRY,a, L vtinömiKIN ATu* otTIME 73 DE FRED VE3FAL 73
Re: [digitalradio] SignaLink USB Interface Reviewed in Popular Communiations, September 2008
On Wed, Sep 3, 2008 at 2:45 PM, Chuck Mayfield [EMAIL PROTECTED] wrote: I will simply make the suggestion that the noise in the original post is not noise, but rather it is interference, i.e. signals caused by the electronics in the unit and not from external sources. Uhhh, while I can understand the significance of the difference if one wanted to modify the unit, from a practical performance aspect, what's the difference between internal interference and noise? Am I missing something? To everyone else, I'm still hoping that someone can estimate the typical noise factor/noise figure for a HF setup and can provide some idea of what threshold the noise performance of a sound card is of no practical importance.
