There is one exception to the rule. Pskmail arq works perfectly with vox. Just a matter of optimizing the protocol to fit common hardware instead of the reverse...
The trick (thanks K9PS) is to send up to 512 bytes of data in a frame and allow some more time for the switchovers. 73, Rein PA0R > -----Ursprüngliche Nachricht----- > Von: "Jose A. Amador" <[EMAIL PROTECTED]> > Gesendet: 26.08.08 17:21:26 > An: [email protected] > Betreff: Re: [digitalradio] VOX not for ARQ modes > > Seems we are reaching the age of the "crippled PC". For a desktop there > should still be a chance of adding a serial port PCI card. I have never > used the parport for PTT so far, and it seems I never will... > > USB is adequate for most common PC jobs, but not for interfacing radios > without some _special_ interface. > > And of course, managing RTS seems to be the most adequate way of > applying PTT to a radio. All other ways (VOX, CAT, etc) seem to > introduce too much latency in an ARQ link. > > VOX may be OK just for keyboarding, which may be the the solution for > most users, but hardly is a "one size fits all" solution. > > 73, > > Jose, CO2JA > > --- > > expeditionradio wrote: > > >> Peter OZ1PIF/5Q2M wrote: > >> Either you have to add an external USB-> RS232 > >> [...] or resort to the VOX solution. > > > > Hi Peter, > > > > For ARQ or handshaking modes, VOX is simply > > way too slow. Signalink will not work. > > Not an option. Let's crunch the numbers: > > > > 1. Really fast VOX with 25milliSecond PTT delay. > > 2. Add 12mSec to 30mSec transmitter 90% power ramp-up. > > 3. Total delay = 37mSec to 55mSec! > > > > Now, let's take a typical example of a slow ARQ > > or handshaking mode running at 125 baud (symbols/second) > > It transmits one symbol every 8 milliseconds. > > In 37mSec, you have missed 4 symbols. > > In 55mSec, you have missed 7 symbols. > > > > Each time you miss some symbols, this creates > > more errors that need to be corrected somehow. > > So, each transmission with a VOX system, you > > create errors... and each ARQ transmission is > > trying to fix the previous transmission's error, > > and the previous errors in the transmissions before > > that... a vicious cycle :) > > > > The other issue is VOX release delay. The longer > > it is, the more the receive decoder will miss > > symbols. > > > > VOX is totally wrong for ARQ modes. > > I'm surprised that Signalink doesn't offer > > any RTS keying, it would be so easy to add > > to their interface. They are really shooting > > themselves in the foot with their design choice. > > A lot of hams are buying these Signalink and > > other VOX interfaces, and they don't realize > > what they are missing by doing so. Of course, > > Signalink doesn't tell them, (the truth would > > be bad for business). > > > > 73 Bonnie VR2/KQ6XA > > > ------------------------------------ > > 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 > > > > > > -- http://pa0r.blogspirit.com ------------------------------------ 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/
