We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - redhat

Pages: 1 ... 77 78 79 80 81 82 83 84 [85] 86 87 88 89 90 91 92 93 ... 106
1261
Software / Re: ZARA Radio on windows 7 or WINE
« on: July 24, 2014, 0522 UTC »
I got bored today and got WINE installed on the desktop configured for XP emulation.  After installing ZARA, I tried to run it, and it does work, with a few caveats.  The program complains that it can't find the windows mixer application, but seems to run fine without it.  Log generation seems to work ok, but don't expect to be able to play music from mounted network storage, at least mine won't.  Local playback from USB drives or local HDD's seems ok.  The program also doesn't seem to like dual monitor enviroments, as when you drag the window to the other monitor it becomes transparent.  The program also doesn't close cleanly.

The long answer, yes it works, but its bitchy.  My desktop has a host of other problems that could also be affecting my success.  Your mileage may vary.

+-RH

1262
There really shouldn't be much to this.  Most drive-in transmitters and the like used an LM1496 modulator followed by a push pull linear amplifier.  As FF said, use a pair of push-pull irf510's or similar running from either a 12 or 24 volt supply.  Use material 77 on the toroids so they will work in MW.  Probably T140-77 for the output wound tri-filiar, with two of the windings joined to form a center tapped winding for the primary.  Circuits like this should be easy to find on the web.

Something like this http://www.sm0vpo.com/tx/15w-pa.htm

+-RH

1263
Software / ZARA Radio on windows 7 or WINE
« on: July 21, 2014, 0933 UTC »
My old air computer is still running XP for one reason only; ZARA will not run on windoze 7.  Has anyone tried it under WINE, or know of a version out there that does run on 7/8/et al?  I would like to move away from the technicolor mafia all together and go linux.

I like the idea of rivendell, but for a request based program this is totally inappropriate, as each cut has to be imported one at a time into it's SQL based library.  That's kindof hard to do on the fly, and a large chunk of the library is scattered across multiple HDD's.

Thanks for the help,

+-RH

1264
Equipment / Re: WWV receiver for ntpd time source
« on: July 19, 2014, 2302 UTC »
Quote
I use a surplus GPS 10 MHz reference with my netSDR. Works great.

I know, I read your article :D

I've been looking for an affordable 10MHz GPS source for a while now.  At least in my case, it would serve two fold, drive the studio clock, and provide a frequency reference for the transmitters :)  I guess I'll have to get some "stratum 1" liners done

+-RH

1265
Equipment / Re: WWV receiver for ntpd time source
« on: July 19, 2014, 0951 UTC »
AFAIK, it's usually easier to use GPS in this application, because the GPS receiver through triangulation can figure out propagation lag and correct for it.  All the studio and CDMA master clock oscillators I've seen are GPS backed.  They have a holdover delay of an hour or so before they fall out of tolerance should the GPS fail.

You can sometimes find used 10 MHz GPS disciplined sources at hamfests and ebay.  They're not cheap, but it might be cool to say you are "the" 6925 KHz reference ;)

+-RH

1266
It's still being used, although not for consumers.  Municipalities use the existing infrastructure to carry telemetry to and from smart meters, lift stations, et al.

+-RH

1267
That was the first requirement for buying a house, no HOA's.....and gas heat please ;D

+-RH

1268
General Radio Discussion / Re: Little White Boxes
« on: July 09, 2014, 2217 UTC »
Quote
...And if I had eaten shawarma


Mmmmmmm.....Schawarma :)

+-RH

1269
One of the fatal flaws of plasma technology is the short life of the panel.  The typical number I used to hear was that the panel will go to half brightness in around 2 years of use.  This is mainly due to ion bombardment of the phosphorus in the individual plasma cells.  Anyone who used to work on color tv's remembers the "ion trap" magnet that was strapped around the picture tube neck.  It's job was to deflect the relatively heavy ions and keep them from bombarding the center of the screen and causing a dark spot.  Because these ions are heavier than electrons, they are not effectively deflected by the deflection system, and thus would repeatedly strike the same area of the screen, causing accelerated wear.  The same thing happens in plasma TV's.  Each plasma "cell" has a low pressure gas, usually xenon and kryton if I remember correctly, an electron gun and the phosphorus.  When the cell switches on, the gas is ionized, and illuminates the phosphorus by bombarding it with electrons, and you guessed it, ions.  I theorize that this is the primary mechanism of wear in the panel.

The reason the panels radiate so much is the length of the conductive strips that connect all the cells in row and column fashion.  on a 60" set, some of those wires are three feet long, and carry large amounts of current when the cells are in conduction.  Because shielding the glass would reduce the brightness of the set, its very difficult to keep the EMI in check.  The best manufacturers can do is soften the initial conduction pulse of the cell as it switches on, which also affects brightness.  Just like a switch mode power supply, the cells are either on or off.  To get variations in brightness, the percentage of time the cell is lit is varied, and our eyes fill in the rest.  DLP systems work on the same principles.

I could be wrong, but after being around a few of them, that's my theory about them.

+-RH


1270
Quote
One of the last remaining plasma display makers –Samsung SDI, an affiliate of the South Korean technology giant Samsung Electronics –announced this week it will cease making the flat-screens used in TVs in November, citing poor demand.

That leaves just crosstown rival LG Electronics, a minor player in the sector, as the sole company in the world still making plasma display televisions.

A spokeswoman for LG said the company will supply plasma TVs “as long as there is demand.” But even so, LG notes that plasma TVs only account for a single-digit percentage of the company’s TV revenue these days.

Japan’s Panasonic, once the biggest player in the field, took much of the steam away from plasma TVs when it signaled a complete withdrawal last year.

    And then there was one.
    LG

Plasma screens were initially touted as the next-generation TV display technology in the early to mid 2000s to replace the thick, cathode-ray tube TVs.  They competed head-to-head with liquid crystal displays, but manufacturers had a hard time mass producing smaller screens at higher resolution and ultimately LCDs began to be adopted more widely in consumer electronics.

Some analysts argued that plasma TVs had more advantages over LCDs including better viewing angles and faster response time.

But LCD technology has improved significantly over time and plasma displays became less attractive.

In the first quarter, only 2 million units of PDP TVs were shipped globally, representing a 16% drop from a year ago, according to research firm IHS. This compares with 47 million LCD TV units shipped during the same period.

Samsung SDI had started out as a display supplier in the 1970s starting with CRTs, developing into a maker of plasma and liquid-crystal-display screens over the years. Now, Samsung’s main display unit, called Samsung Display is mass producing more advanced organic light emitting diode (OLED) screens which are thinner and more energy efficient than LCDs. Many industry experts believe that OLED will ultimately replace LCD technology though manufacturers are having difficulty producing OLED screens in mass volume, especially for large televisions.

In an interview with The Wall Street Journal last year, Samsung SDI’s chief executive said the life span of plasma panels is nearing an end and it will gradually shift production.

 – Juro Osawa in Hong Kong contributed to this article.

Mu guess is ROHS has something to do with their demise, as does the difficulty of getting energy star certification.  Any way you slice it, they still need phosphorus and a handful of other nasty chemicals to make the panels.  That coupled with the power consumption makes the sets anything but green.  They still produce a picture that in my opinion LCD and LED will never touch.

I was recently at an electronics store and they had one of the new OLED TV's on display.  It looked like a1970's TV with a flat red gun :(

+-RH

1271
The US radio industry magazine, or the UK CB magazine?

+-RH

1272
This looks like a blast.  I'm going to have to do this before I die :)

+-RH

1273
General Radio Discussion / Re: Propagation
« on: July 01, 2014, 0106 UTC »
Although there is no question that prop has been somewhat disappointing over the last couple of weeks here, I attribute much of the tough copy to the Rice Krispy atmospherics courtesy of the Summer T-Storm season. Nothing worse than straining through the noise and having a major static ear bleeding blast from a lightning strike somewhere! And yes, that was a surprising TA opening last night Chris! I'm just listening back now on the recording I made of Black Bandit on 6320 and it was nothing less than amazing!

That's what noise blankers are for :)

+-RH

1274
QSLs Received / Re: NORTHWOODS RADIO POSTAL QSL
« on: June 27, 2014, 0716 UTC »
Very nice score :)

+-RH

1275
Huh? / Re: The World Cup of Soccer
« on: June 26, 2014, 0317 UTC »
Yeah, I like watching the game though.  Lots to look at.

+-RH

Pages: 1 ... 77 78 79 80 81 82 83 84 [85] 86 87 88 89 90 91 92 93 ... 106