Messages

76

General Radio Discussion / Re: The Weird Machine That Measured Radio Audiences in the '30s and '40s

« on: April 20, 2019, 0628 UTC »

This reminds me of the story in the early 1990's EBN from Ernie Wilson, (Yeah, the ex-Panaxis Productions dude.). This story was about how a French TV station engineer noticed a minute more RF current drawn at the transmitter site right at the time a well watched soap opera aired, then after it would air, the minute current level dropped back down to where it was set. I thought that it was an interesting observation, but never heard anything about it since. You'd think that someone would have wanted to do the math more and figure out the TX RF current to the number of RX stations tuning in. Oh, wait... That might just put the Nielsen Ratings out of business.  So, never mind...

How would a receiver several miles away affect current draw in a transmitter?

Unless the engineer was reading the current of the power grid itself? I can see how a power company could notice a change in current draw if everyone in a city turned their TVs on at the same time. But in today's multichannel world, I don't think anything like that would work.

It's an old myth. I've heard that story eons ago and it's always told in a slightly different form. It is similar to the story of a guy who lived near a high powered AM radio station and setup some wire antenna outside to capture the field strength of the local station to light his attic at night only to get a knock on the door because the station engineer noticed the transmitter RF ammeter raised significantly causing tube failures or something as such.
They are fun tall tales

77

Equipment / Re: The SW200 LPAM, Part #15, Amateur Radio AM, Audio Processor.

« on: January 28, 2019, 0027 UTC »

Here is more information about it and the overall internal layout and flowchart...
https://aa7ee.wordpress.com/2018/03/13/the-sw200-a-budget-am-broadcast-processor-for-lpam-and-hams-too/

I am actually building my own AM audio processor that is similar in layout but uses FET compressors instead of PWM compressors for simplicity and is loosely designed after the Dorrough DAP 310 from 1973 which is yet another popular 3 band compressor/clipper of its time (some say the first of its kind that started the loudness wars). Luckily the Dorrough schematics and manual are available online so it's not too hard to clone your own similar box if you have a lot of time and electronics skills. It's actually pretty simple under the hood, tons of op amps though. The SW200 looks to be similar while utilizing modern parts.

Software processors rival even the best analog processors except when it comes to the audible latency. I really love Stereo Tool and have an excellent AM preset I found a while back for it and tweaked. It gives *loud* punchy audio that is equal to the major market radio stations in my area and can really drive a modulator hot. The problem is that there is the need of a fast dedicated computer with a quality sound card and ASIO4ALL really needs to be running to make the latency the least noticeable. The OS needs to be stripped to bare bones so the computer can dedicate all its processing to the software and not other useless junk.
Even with the fastest computer I have it had delay that was enough to drive me crazy for live programming and really screws with my head if I listen to myself talk over the live feed.
Of course this can be fixed by only listening to the program feed output rather than the live OTA feed, but I like hearing the transmitted audio through my modulation monitor.

So in that respect I still prefer analog audio processors where suitable and if setup properly can still sound pretty damn good. If all you are broadcasting is prerecorded shows or only listening to the studio audio then digital processing is fine.
Comes down to personal preference but digital processing will give the edge, and possible listener fatigue if overused.

On a funny side note, I have heard of stations using their retired analog processors just for the studio talent since it's real-time and let them hear that "radio sound" in their headphones while using the new digital processor at the transmit end so to trick the DJs and not anger them with the delayed live processed audio

78

North American MW Pirate Radio / Re: Community Radio Network 1710 AM 0144 UTC 19 December 2018

« on: December 21, 2018, 0941 UTC »

Heard a station playing old music and some quick Christmas jingles tonight.
0224 - "Moonlight Serenade" by The Ray Eberle Orchestra.
The Sept. 11 memorial station occasionally fades up to dominate the frequency.

I'd love to know what music. I was just running a test broadcast with mostly Christmas music then went into a Devo escapade because I drank. Real curious if this rig is getting out on 1710kHz, long work in progress. Running 25 watts but the antenna needs far more work. I will probably run this all christmas on and off until it's perfected. http://darkliferadio.proboards.com/thread/1018/class-series-modulated-transmitter-build

79

North American Shortwave Pirate / Re: UNID 6950 USB 0157 UTC 17 June 2018

« on: June 17, 2018, 1501 UTC »

Listened into this last night but was too tired to grab my tablet computer to decode the SSTV, glad others here uploaded them!
Neat show, Kraftwerk fan myself so was nice to hear their music for the first time on shortwave
Signal was decent for the storms in the midwest, SINPO 55354

80

10/11 meters / What is with 11m lately?

« on: May 24, 2018, 1157 UTC »

Anyone else notice that even though we are on the low end of the 11 year cycle the CB band is picking up big at times I never recall? Yet lower frequencies are completely dead. It seems 10+MHz is doing swell but anything lower is worse than ever! I tuned in 80m last night and heard two hams and that was it, yet at the same time I heard hundreds of people on CB 11m.
Right now as I post this, 6:55AM EST I am hearing skip from all over, that's not normal. Even at night lately and last night I heard people talking skip into the moon hours.
What is up with the sun? I thought when we are on the cycle low we are working local only but I am hearing stuff that reminds me of years ago when the solar cycle was high.
What gives? Am I going nuts?
Meanwhile I can't even tune in coast to coast am at night, how will I sleep w/o george snoory telling me bedtime stories?

81

Huh? / Re: The definitive end-fed dipole discussion.

« on: February 28, 2018, 2220 UTC »

Where do I install the tophat and monocle to focus the beam width toward the hemorrosphere layer? 

82

10/11 meters / Re: 27025 AM CB Superbowl Ch.6 1925 UTC 29 DEC 2017

« on: December 31, 2017, 0956 UTC »

Yeah there seems to be a lot of skip right before noon on 11 meters in the last few days. Guessing it's some sporadic E activity given the low solar flux. Kind of nice to work some skip when the band is so damn dead the rest of the time besides the local weirdos and truckers.
Using my homemade EFHW mounted 30' up which has the same performance as an Antron/Solarcon A99, I get activity across all 40 channels when skip comes in. At the peaks I switch to the freeband frequencies and those can become quite clogged too. Helps to have an actual CB and antenna designed for the band, but ch. 6 is always a reliable indicator to see if the band (including 12 and 10m) is opening up.
Oddly I have yet to hear anyone on 10m besides some CW. CB 11m on the other hand lights up like a Christmas tree.

83

North American Shortwave Pirate / Re: Unidentified Radio 6940 USB 2255 UTC 26 Dec 2017

« on: December 28, 2017, 0337 UTC »

Was listening while they played Smash Mouth and STP. Was too tired to listen further but signal was good here in WI with slight fading. Nice clear modulation.

84

Huh? / Re: The Penguin Brief

« on: May 03, 2017, 1832 UTC »

Linux for life!

85

The RF Workbench / Re: Stretchyman Pirate Radio Video

« on: May 01, 2017, 1617 UTC »

Incredible work
Makes my perfboard homebrew look like crap lol. One of these days I will get around to making my own PCBs for projects.

86

Equipment / Re: very interesting transceiver

« on: February 18, 2017, 0318 UTC »

Windows 10? I'll stick to my penguin based SDR thank you.

87

Shortwave Broadcast / Re: Brother Stair on WBCQ, 9330 kHz

« on: February 03, 2017, 1231 UTC »

What isn't Brother Scare on these days?

88

The RF Workbench / Re: Help with an FM Jammer

« on: December 24, 2016, 1831 UTC »

Alternatively, you could modulate the oscillator with a sawtooth waveform which would be more annoying to the 'victim'.

Sawtooth through a varactor diode as half the tuning LC circuit to sweep frequencies around the range you desire, nasty thought
That is definitely one way to piss off some people.

redhat is right though, you should use either a zener diode and resistor to regulate voltage going into it or even something as simple as a three leg 5v regulator like a 7805 so that the free running oscillator doesn't drift around.
It's funny because as simple as this circuit looks, this is the one place where engineers start pulling hair because LC oscillators are the most finicky part of a far more complex RF circuit.
Want to get real nasty I recommend a push pull oscillator at half the frequency which runs in anti-phase to get up to the frequency you want to block. Far more stable and will create enough blackout at the frequency if you want to get in some trouble.

In all practicality though wouldn't it be easier to use an FM MP3 player transmitter set to the channel you hate and want to block? Add a piece of wire on the circuit for an external aerial and you're set. Run some fart noises into the audio input to annoy further, and remain somewhat legal doing so.

89

General Radio Discussion / Re: THE SUN HAS GONE COMPLETELY BLANK

« on: June 07, 2016, 2122 UTC »

What's going on in this thread? Where am I?

90

Software / Re: RTLAMR Smart meter monitoring

« on: March 13, 2016, 0647 UTC »

I've tried, but not picked up anything. I did some research, and it seems the meters used here (BGE) use a different protocol.

I was able to see the water meter usage but the electrical meter here uses a different protocol as well. Interesting piece of software though. Tested it out on Linux using an rtl2832u TV tuner dongle.
This was a while back so I should see if the latest version includes our other meters here when I get the chance.