That's a known problem in firefox. What's your browser? FF4betaX solves it.

George,
it would be nice to make the balloons show the last post when mouse-over the number in a multipage thread, and show the text of the last poster when mouse-over the callsign/login name of the last poster on the Posts right column.

Thanks for your work,
73 de Fer

Sorry about my wrong statement. I've edited it just for correctness, although I think  it's very clear by now that it should have been 1.41 and not 0.707.

Thanks a lot for the corrections (Cecil, Dan et alter) and sorry Jerry for the mistake, and taking so long on returning to this thread.

73

Hi.

Vmax = Va * sqrt(SWR)
Vmin = Va * (1 / sqrt(SWR))

Where Va is the adapted condition max. voltage (or current), and Vmax is the max voltage in the line when SWR!=1:1, and Vmin is the minimum voltage in the same condition.

For example, if you're working with a 50 ohm line where the SWR = 9:1, and you try to put 1500 watt into it, then you have:
Adapted condition: VpeakA = sqrt(2) *  sqrt(P*R) = 1.41 * 273 = 386 V         [1]
SWR 9:1 condition: VpeakSWR = VpeakA * sqrt(SWR) = 386 * 3 = 1158 V

Then you have to be sure that the breakdown voltage of the line is above that value. This works for currents too.

73


[1] There was this line originally: Adapted condition: VpeakA = (sqrt(2)/2) *  sqrt(P*R) = 1.41 * 273 = 386 V
     The (sqrt(2)/2) is an error, it's not 0.707 but 1.41 instead, as pointed out by KM3K down in the comments.

Hi.
Before investing in a shielded CAT-5 cable, I would get the wireless transceiver down and run a couple of tests on the bench. I came across some devices that have internal DC-DC converters that are pretty noisy and the unit, being integrated with the antenna, is not easily modifiable. Perhaps you can get a new unit of a different brand to replace it if you found the problem is in the unit itself.

I have some 5.8 GHz Ubiquity (couple of years old) that are very quiet in the HF spectrum. Never used the 2.4 GHz stuff though.

73 de Fer

Hi.
WSJT leaves the WSJT.LOG file in your configuration folder (I'm on Debian, it's  ~/.wsjt here; try under Documents&Settings/username/Program data or something like that if you're on window$).

WSJT.LOG is a text file. One entry per line, comma separated fields, i.e.:

2010-Aug-10,21:59,W8WN,EM77bq,7,JT65A

[date,time, hisCALL,gridloc,band,mode]

It's easily parsed and transformed for importing into another log program.

AFAIK there's no built-in mechanism for exporting the log in WSJT.

73 de Fer

Get and old good server from IBM, strip it and use the case. See that the case is complete with all the shield plugs for the disk bays unused; those plugs have large surface for good contact with the case.
The PSUs in that servers are very well filtered also.
You can get a complete working machine for less than the basic oriental case costs.
73

I'm a little tired of nets or roundtables or whatever you call them these days operating semi-duplex over the air (semi-duplex on radio: the other party is NOT really hearing anything in the radio).  It's not that I was very attracted to nets anyway.

I really can't understand the point of "completing" the net by other media... This is about _radio_, not _communication_ isn't it? Because if the point is communication, then IRC or video conference over TCP/IP is way more reliable, cheaper and easier.
And Skype has a conference mode, as most other phone services ;-)

73 de Fer

I really don't trust all the explanations they circulated, because corporate reasons and marketroid gibberish would probably hide very deep the real cause of the failure; we'll probably never know.

What I *do* know is that Apple products this days are not so technologically advanced as they was some years ago, nor in hardware or software. So this devices (iPhone and iPad) are really only super overpriced "hip" jewelry. For this reason, they need to make it development very secret, and specifically avoiding alpha and beta stage testing from a third party. This model of development can produce this kind of failure even when yo have an army of well paid testers. The iPhone is FUBAR because of the antenna. The iPad is FUBAR too, because of the software it runs.

By the way, take a look at the anechoic chamber (US$100M) where the designs are evaluated:
https://www.apple.com/antenna/testing-lab.html (apple.com).


73 de Fer

Hi.
You're not providing enough information. What's the layout of your LAN? Can you ping from PC to PC and PC to router? Are you using static IP addresses or the router provides a DHCP service? Are you over wi-fi or UTP? How about DNS servers?

My guess would be the problem is on that slow-downloading PC or on the link to it.

Best regards,
Fer

Your own emission would travel around the Earth in ~143 ms and this echo is common. If the signal you saw was delayed by several seconds, then it's a long delayed echo (LDE) phenomena.

There are several hypothesis for the LDE; one is that the signal is trapped between two ionized layers in the ionosphere and after several turns around the Earth (for a 3 sec delay that would be about 21 turns) the wave escapes the ionospheric "trap" towards the ground at some discontinuity in the bottom layer.

This effect is very sporadic, and there is always the possibility that a joker is re-playing your transmission... in digimodes this is even more simple than in CW or phone: copy&paste, Enter ;-)

73 de Fer

Yes, make the round table directly over the 'net, because that would eliminate the problematic part, that is, the *radio* part.

Hi George,
thanks for your answer.


For consistency I'd suggest to show the empty post in a way similar to the ignored user posts.  That's probably involves not allowing the deletion of the post itself, more like to add a delete flag to it or as you said, letting the user delete the content of the post and not the post itself.

Related to this: seeing my original post I think the title spelling is wrong, I think it should be "in forum" and not "on forum". Anyway, it's not possible to edit a post title, right?

73 de Fer

Hi.
Reading this long thread in Elmers: http://www.eham.net/ehamforum/smf/index.php/topic,68166.0.html
I've noted that some posts seems to be missing or hidden.

For example, reply #86, by W5DXP on May 22, 2010, 05:37:53 PM quotes a previous post by VK1OD on May 22, 2010, 05:12:30 PM, which I can't see in the thread.  There is no such post at the time of the quote, but the replies numbering is correlative.

Is this a feature or a bug?

Thanks.
73 de Fer

And how a string of diodes would provide regulation?
73

Hello.
Simplifying a lot, if both your station and the other station antennas are both at 12 m (40'), each one has a radio horizon of ~15km, so the path between both stations is ~30km.

Elevating both antennas to 24m (80') the radio horizon extends to ~20km on each side, providing for ~40km path between the two.

Antenna gain has nothing to do with line of sight propagation provided the ERP is enough for the signal to cover the distance between the stations.


All other conditions the same (power, line loss, etc.), height.

73