*** more AA6YQ comments --- In digitalradio@yahoogroups.com, "Jose A. Amador" <[EMAIL PROTECTED]> wrote:
+++That's an unreasonable requirement, Jose, especially given that PMBOs use a protocol that can't be implemented with soundcard software on a Windows PC. The cheapest Pactor TNC capable of running Pactor II and III costs in the range of $1K. Are you suggesting that all digital hams must purchase one of these in order to protect themselves from Winlink QRM? It did not start as a sound card mode. It dates back to the age of boxed controllers, around 1999. *** Pactor II and III didn't start as sound card modes and still aren't sound card modes, at least on a Windows PC. The basic cost of a PTC, nowadays, brand new, is around 600 euro. Of course it is not reasonable to ask it. And I HAVE NOT asked for it. *** Then why did you bring up the point that PMBOs can detect ongoing QSOs in Pactor? If you weren't suggesting this as a solution, then what was your intention? Dave, how much actual operating do you do on the air? I have only heard you once on PSK31, around 14071. *** You'll find my digital mode stats in http://groups.yahoo.com/group/digitalradio/message/23572 *** I've never heard you at all, Jose. By your logic, you must never operate. How many times a PMBO has actually stepped on you? *** I have been QRM'd by what looked like Pactor II or Pactor III signals quite a few times on 40m and a couple of times on 30m. Only in the past couple of years have I been able to know for certain that these events were PMBOs by firing up the PTC-IIe that SCS sent me. *** I have also used Winlink, for whatever that's worth. ### Of course; at constant cost, we have 2-4X more CPU cycles now that we did then. Algorithms that were computationally out of reach 4 years ago may now be practical. That is on a PC. I meant available technology in multimode controllers. Have the PTCs made by SCS evolved likewise? I think they haven't, in a similar amount. The PTC's so far only detect activity from modes alike to the mode it is set to. And so far, also, Pactor has proved to be a better protocol than SCAMP, and alive, with relatively frequent firmware updates. *** It is not necessary to implement the multimode busy frequency detector within the SCS box. Remember, its only PMBOs that need busy frequency detectors. One could run the SCAMP busy frequency detection software as process on the PMBO host (using a soundcard to monitor the RX output). The PMBO station management software would be modified to take the output of the SCAMP busy detector into account. Some time ago, I described the basic state flow for this approach in a thread here; it would likely be less than a day's work to implement, followed by some serious testing. ### The SCAMP busy detector (as it existed years ago) could be deployed in Winlink PMBOs today and reduce QRM by a significant factor. Could it be improved; almost certainly. Would this improvement be a prerequisite for deployment? Absolutely not. How many years ago? The SCAMP Protocol Specification Draft Rev Q is dated 2/1/2005. *** 10/15/2007 - 2/1/2005 looks like 2 years, 8 months, and 2 weeks ago to me. ### First, I'll note that you didn't answer the question I posed: why did you bring up the hidden transmitter effect if not to use it as an excuse for PMBO-generated QRM. I mentioned it because it is a physical fact. *** Its a physical fact that I fully acknowledge, and yet you accuse me of distorting physical facts. *** You even told that Steve Waterman said there is no hidden effect. And I told you he might have had his reasons, which I don't know, and are not my reasons. ### Yes -- my point was that you were accusing the wrong person of denying the hidden transmitter effect. The denial of this effect is implicit in the design of Winlink. I do not need to hide the existence of the hidden station effect. I believe on that, as a fact of life. I am not seeking excuses for the Winlink design. I just have been a user, and a grateful one, indeed. But if I understand reality is being twisted and confusion created, I feel it hard to remain silent. *** That's a serious accusation, Jose. Exactly where have I twisted reality or created confusion? ### The only evidence of "hidden transmitter effect denial" is in the system design of Winlink. I have not seen that statement with my own eyes. *** Then let me help you see it, Jose: WinLink is based on the assumption that the remote initiator can reliably verify that the frequency is clear before activating a PMBO. This assumption can only be true if there is no hidden transmitter effect. *** Said another way, were Winlink's designers to acknowledge the existence of the hidden transmitter effect, they would also have to acknowledge that their PMBOs will occasionally QRM ongoing QSOs - which they have steadfastly refused to do. OK. I understand you will not come forward with a better SCAMP. *** Actually, Jose, I recruited Bob N4HY and Peter G3PLX to work with me on developing a soundcard-based protocol that would replace Pactor as the transport for Winlink. But the WinLink guys made it clear that they would never use it, so we stopped. ### If its not hard to do, then do it. I feel there is no need. The group postings are public for anyone interested in counting them to find by himself / herself. I might have less on my mailbox (for several reasons) than those on the group archives, and I do not want to minimize your participation at all. *** All messages are available via http://groups.yahoo.com/group/digitalradio *** Bottom line: you can't. ### And what does "overly recursive" mean, exactly? Your repeated postings about this anti Winlink stuff, as I understood, denying the existence of the hidden station effect. If you finally admit it DOES exist, that's OK with me. *** You made this up. There is no post by me anywhere on this reflector or on any other venue in which I've denied the existence of the hidden transmitter effect. To the contrary, I have repeatedly pointed out that Winlink's design fails to take this effect into account, the result being its QRMing of ongoing QSOs. You accepted the fact that the hidden station is a physical fact. It really bothered me to see once again stated that it did not happen. *** You'd best go re-read whatever post it was that made you think I said that, because I didn't. If I'm wrong, point it out; shouldn't be too hard, it would have been within the past 24 hours. 73, Dave, AA6YQ
