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eHam Forums / CW / RE: Future CW speed?
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on: November 29, 2011, 01:52:49 AM
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Some think that future averaged code speed, will be around 10 wpm, because of no code testing and the natural loss of older full time code operators? Do you have an opinion?
I do not think this will become true. Considering the recommended training methods, train the characters themselves at the speed you want tol archiee, which is highter then your projected 10wpm. 73 de Luc, LX2GT |
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eHam Forums / Digital / RE: The new Kenwood TS-590 is a great digital rig
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on: September 23, 2011, 04:04:06 AM
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When I wanted to start again with ham radio about a year ago, also also decided to get me something new, and got myself a TS-590. Always enjoyed digital modes, and with this rig it is so easy to operate, and no cables hanging around nobody does need. I also looked at the K3, but was not quite ready to spend that much.
Now, If I only could find some more willpower to re-learn CW.
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eHam Forums / Elmers / RE: Opinion on verticals
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on: August 15, 2011, 11:50:01 PM
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The AV-640 is a fine vertical antenna, I have used it at 2 QTH's so far. I especially like, that each band can be tuned completely independently. Tuning it is an one time operation, erect it, measure the frequencies, change the tuning according to the manual, and you will be where you want it.
I did not want to ground mount a Vertical, as in my garden of my current property there is a nice lane, build out of concrete, that I do not want to remove, and as such radials on the ground are not practical. Aditionally, being in an river valley, I wanted to elevate it, as more height will surely help it.
The AV-640 works surprisingly well on 40m I have found out. I cannot compare it to any kind of horizontal antennas though, as there is just not a point to attach one here.
73 de Luc
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eHam Forums / Digital / RE: My software for testing Amtor-ARQ
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on: August 10, 2011, 05:21:20 AM
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There is actually existing at least one AMTOR ARQ Implementation in Software, that does run on PCs, do take a look here: http://hfterm.sourceforge.net/It also does Pactor I. My experiences with my PTC II back in the day however was, you did CQ for like hours, nobody really was interested in an ARQ QSO. Mailbox Traffic seemed more interesting I guess, but boring over time. That was before the Soundcard modes and PSK31 even. |
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eHam Forums / Digital / RE: Other modes besides PSK?
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on: May 20, 2011, 02:19:32 AM
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Interesting Discussion, which seems to be recurring here and there. The popularity of a digital mode is not purely a technical one, but also a human one. The publication from Peter, G3PLX contained the following: What is needed for a live contact?
I believe that it is the error-correcting process used in modern data modes which make them
unsuitable for live contacts. I have identified several factors, the first revolves around the fact
that all error-correcting systems introduce a time-delay into the link. In the case of an ARQ link
like AMTOR or Pactor, there is a fixed transmission cycle of 450mS or 1.25 sec. or more, which
will delay any key-press by as much as one cycle-period, and by more if there are errors. With
forward-error-correction systems there is also an inevitable delay because the information is
spread out over a period of time. In a live two-way contact, the delay is doubled at the point
where the transmission is handed over. I believe that these delays make such systems
unpleasant to use in a two way conversation.
This is not so much a technical problem as a human one. Another factor in this category is
concerned with the way that the quality of the information content varies as the quality of the
radio link varies. In an analogue transmission system such as SSB or CW, there is a linear
relationship between the two. The operators are aware of this all the time and take account of it
subconsciously: they change the speed and tone of your voice instinctively and even choose the
topic of conversation to suit the conditions. In a digital mode the relationship between the signalto-
noise ratio on the air and the error-rate on the screen is not so smooth. The modern errorcorrecting
digital modes are particularly bad at this, with copy being almost perfect while the
SNR is above a certain level and stopping completely when the SNR drops below this level. The
effect is of no consequence in an automatic mailbox forwarding link, but can badly inhibit the
flow of a conversation.
A third factor is a social one: with error-correcting modes you only get good copy when you are
linked to one other station. The copy is decidedly worse when not linked, such as when calling
CQ or listening to others. This makes it difficult to "getting to know" other people on the air and
there is a tendency to limit contacts to a few close friends or just mailboxes.
These factors lead me to suggest that there is a case for a transmission system that is not
based on the use of error-correcting codes, when the specific application is that of live contacts.
The continued popularity of traditional RTTY using the start-stop system is proof of this
hypothesis: there is minimal delay (150mS), the flow of conversation is continuous and the errorrate
is tolerable, and it is easy to listen-in and join-in. Source: http://det.bi.ehu.es/~jtpjatae/pdf/p31g3plx.pdfI kinda agree with what he writes there. On a related note, I still remember PSK31 times, when most people did use those DSP evaluation boards to run it, and Hansi, DL9RDZ offered the first ever implementation of PSK31 using a PC soundcard... running linux, in console mode. Then came that qso between DL9RDZ and G3PLX, and short after that the first windows based psk31 soundcard implementation. Good Memories... 73 de Luc, LX2GT |
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eHam Forums / Satellites / ts-2000
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on: January 18, 2005, 03:46:11 AM
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Well, in fact you CAN work full duplex in FM including the PL tone, using a small trick. Don't use Satellite mode, tune the downlink on the main VFO, uplink on the sub receiver, CTRL to main band, PTT to sub receiver. This way you will receiver on the main band, and transmit on the sub band. It will not mute the main band during transmit. Note, the PL tone needs to be configured on the sub band rx.
73, Luc
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