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Messages - redhat

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1366
About S9 here, but no modulation, and a good bit of fading.

2315z I/S now running.
2318z Long pause in modulation, then the carrier petered out... TX issues?
2320z Back running I/S

+-RH

1367
General Radio Discussion / Re: coolest DX catch
« on: February 01, 2014, 2259 UTC »
It was a Saturday in July, 2006 or so and I was in a hurry to leave the house to help with a film screening in a neighboring state.  I had borrowed a Denon TU-1500RD from work as I was testing some equipment at home and needed something with RDS.  I had a 6 element ratshack beam on the roof with a rotor, and I was just dialing around when I heard something I didn't recognize, it was spanish.  I was pretty close the the Canadian boarder, so spanish FM was a rarity.  I had the beam pointed south, and a few seconds later, the display lit up and said "Exa 98.3."  After doing some research, I found out the station was just off the tip of texas, close to 2000 miles away.  Begrudgingly, I had to leave, but on the way out the door, I called my friend across town and left a voicemail and told him he may want to turn on his tuner and see what he could hear.  A few days later, we went through the tape he recorded and ID'd 26 stations in half a dozen states, some over 1000 miles away.  The APRS map was full of red that day, and I don't recall an e-skip opening that good since.

Several years later, I was letting an FM exciter run some music for the house, and I had a Sony XDR-F1HD running with a wire dipole in the window.  I think it was June or July again.  I had a streaming station feeding the transmitter, and was minding my own business when suddenly the music changed.  I looked at the transmitter to be sure it was still running and it was, then the music went back.  This happened a few more times, and this time I looked at the radio, and it was decoding HD from a station I'd never heard of.  Looked up the call sign and it was from the Phoenix metro, close to 1000 miles away.  I scanned the dial and found a few others that were making the journey.  I called the phone number for one of the stations and asked  for the chief engineer, then proceeded to tell him his HD's were being heard almost 1000 miles away.  He was a bit surprised.

+-RH

1368
The RF Workbench / Re: Stereo to mono wiring
« on: February 01, 2014, 2246 UTC »
Your MP3 player probably won't care if its output are tied together, but if your worried about it, use a 1-10K resistor in series with each channel to sum them together.  That's all you really need.

+-RH

1369
General Radio Discussion / Re: FCC notice of unlicensed operation
« on: January 31, 2014, 0826 UTC »
ERP = (ed/7.02)^2

e= field strength in uV/M
d= distance in Meters

It is kindof a crap shoot for reasons previously mentioned; you have no idea what the measurement conditions were like.  Plus, who knows how they measured the distance to the antenna.  Generally, field strength is measured in the main lobe of antenna radiation, which would be in line with the transmit antenna.  In many cases, that's simply not possible.

+-RH

1370
North American Shortwave Pirate / Re: X-FM 6925 AM *0118 UTC 31Jan14
« on: January 31, 2014, 0151 UTC »
A vertical it is, 3KW it isn't....Wish it was.

+-RH

1371
QSLs Received / Re: Radio Ronin eQSL
« on: January 30, 2014, 1350 UTC »
Got one here too.  Thanks Henry!

+-RH

1372
Equipment / Re: Calibrating S-Meter
« on: January 29, 2014, 1547 UTC »
The only way you'll be able to calibrate it is with a signal generator.

+-RH

1373
+1, even though from what I can remember, it wasn't that good even then.

=-RH

1374
Well, I for one still watch over the air TV.  I don't watch enough TV to justify paying for cable.  Particularly in larger markets with diverse ethnic populations, over the air is still the norm.  You know the old saying "57 channels and there's nothin' on."

+-RH

1375
General Radio Discussion / Re: Shortwave pirate stations
« on: January 27, 2014, 0150 UTC »
As I understand it, most modern era pirates run close to 40M.  This is because it offers a good balance of daytime and nighttime propagation.  It also doesn't hurt that antennas in this range are less unwieldy that the lower bands.  People do operate around 20M as well, but not as many.  USB is probably the most common mode used, AM a close second.

+-RH

1376
Hearing the sign on now.  About S8 with good 5K audio with occasional Peskies on USB.

0029 Radio Ronin ID follwed by Kenny Wayne Sheppard's "Blue On Black"
0041 Instrumental Blues piece followed by RR's "Rock Your Radio" ID
0053 RR "Ionopshere" ID followed by "Howdy Folks, and welcome to DFW"  a reference to "Big Tex" the robotic host of the Texas state fair.
0057 RR ID with email addy.  Signal starting to barber pole a bit, signal also a bit weaker, now down to S7 or so

Other projects are vying for my time, but thanks for the tunes my brother!

+-RH

1377
The Kahn method is how high power shortwave transmitters generate SSB with good efficiency.  I imagine this paper was targeting cell phone PA's to extend battery life.

+-RH

1378
General Radio Discussion / Re: FCC notice of unlicensed operation
« on: January 26, 2014, 2350 UTC »
Based on the number in the report, he was running about 355W ERP.  I personally know a few people who have been busted running far less :)

+-RH

1379
My point was that, series modulation does work, best at low power levels because of the inefficiency involved.  If you were going to do high level PWM ala Harris's MW-5, et all, thats a different story.  High level PWM does work very well, and even today's solid state MW and SW transmitters under 6KW use this principle.  To my knowledge, the only domestic manufacturer of high level tube PWM transmitters is continental electronics.  They have a 50KW "Solid state modulator" which is essentially 48 750V power supplies individually series modulated with PWM and wired in series to get 10KV average B+ for the final tube.  The benefit; no modulator tubes, high efficiency, and lower operation costs.  The custom plate transformer which rolls on railroad track by the way, must be a pricy one.  Never mind the fiber optic drive system.

+-RH

1380
General Radio Discussion / Re: homeland security
« on: January 24, 2014, 0122 UTC »
I'm not sure if they would be trunked or not.  P25 is the norm now.  I worked for a TV station at one point that bought a P25 capable scanner for news purposes.  All the stuff they wanted to hear was encrypted :)  This is also becoming the norm for EMS, fire, and police, at least in the areas I've surveyed.

Good luck,

+-RH


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