This is very weird, I am picking up the TV on SW radio plus my Satellite dish uplink too. Freqs: 9005 khz and 9085 khz this is so "freqky" get it lol
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TV on SW Radio?
- Thread starter eskipper411
- Start date
No everytime I changed the channel, the sound would change on SW toogr8oldies said:
K
kenglish
Guest
KTBN Shortwave got turned off in March of last year. It all went to "Pastor Mellissa Scott" in the Caribbean.
Here's a photo (Bird's Eye View) of the site, during demolition. Note the oceangoing cargo container:
http://www.bing.com/maps/default.as...&phx=0&phy=0&phscl=1&scene=32584645&encType=1
Here's a photo (Bird's Eye View) of the site, during demolition. Note the oceangoing cargo container:
http://www.bing.com/maps/default.as...&phx=0&phy=0&phscl=1&scene=32584645&encType=1
gr8oldies said:
Yep, I hate that when it happens! What frequency/frequencies is this coming out on your SW radio? These are often caused by Intermediate Frequency (IF) circuits in the TV and might be from poor shielding of those IF circuits or the IF circuits might be out of alignment in an older TV. Newer TV's have much of their RF circuits in Microcircuits - ICs - 'Chips' - so there is usually nothing user-friendly to align. Moving the SW radio and/or running shielded coaxial cable to an outdoor antenna should clear it up, it did for my setup. Of course, turning the TV off is the easiest solution if the interference is messing with reception...
I route my satellite, converter box, PS2 all through the VCRswmaphox said:
get a band pass filter for your vcr...
A little O/T I am here ...... and certainly not offering a possible solution because of the move of stations to other channels ...... but what were the frequencies on which the VHF stations broadcast their audio?
All I can remember is that Channel 6 was just below the FM dial at 87.75, and that Channel 7 was 200-something mHz.
Were the other VHF's sequential? Was Channel 5 lower on the dial (longer wavelength), and Channel 4 lower than that?
Etc?
And if the channel numbers numerically paralleled the broadcasted frequency, was there any pattern, or did they just find blank spots?
All I can remember is that Channel 6 was just below the FM dial at 87.75, and that Channel 7 was 200-something mHz.
Were the other VHF's sequential? Was Channel 5 lower on the dial (longer wavelength), and Channel 4 lower than that?
Etc?
And if the channel numbers numerically paralleled the broadcasted frequency, was there any pattern, or did they just find blank spots?
There was a thread that I was involved in at one time that discussed what cable channels were equivalent to what OTA channels and the frequency ranges were also brought up. With the search not working I haven't been able to find it yet. I've tried using the search engine The Dude started, but haven't had any luck there either for now. If I can find it I'll post it.
Basically though, channels 2 through 6 are just below FM radio with some spaces. Channels 7 through 13 are in another block above FM and aircraft/public service bands, and the UHF channels from 14 up are in another block.
I have a radio that is still at my mother's house that picked up channels 2 through 13 and also had a UHF band that overlapped to where it would pick up the audio from some lower UHF TV stations. I could get WJKT Fox 16 in Jackson, TN, but nothing else in my area.
Basically though, channels 2 through 6 are just below FM radio with some spaces. Channels 7 through 13 are in another block above FM and aircraft/public service bands, and the UHF channels from 14 up are in another block.
I have a radio that is still at my mother's house that picked up channels 2 through 13 and also had a UHF band that overlapped to where it would pick up the audio from some lower UHF TV stations. I could get WJKT Fox 16 in Jackson, TN, but nothing else in my area.
About 80 years ago, Francis Jenkins from Indiana had a television station on SW. People built their own TV sets to watch his movies all over the world.
This was in the 1920's.
It was new and exciting back then. People didn't mind the fading.
Jenkins also invented motion picture projectors, fax machines, internal
combustion engines, and milk cartons. He died broke on his a##.
This was in the 1920's.
It was new and exciting back then. People didn't mind the fading.
Jenkins also invented motion picture projectors, fax machines, internal
combustion engines, and milk cartons. He died broke on his a##.
Steve Green NEPA said:
Each TV channel was (and is) 6MHz wide and numbered in order by increasing frequency. But there are some gaps where other services received some spectrum. When a channel was used for analog service, the audio was transmitted 0.25MHz below the top of the channel.[0] Channel 6 is 82-88MHz, so 0.25MHz below the top of the channel is 87.75. Some other channels:
Channel 2: 54-60MHz, audio on 59.75
Channel 3: 60-66MHz, audio on 65.75
Channel 4: 66-72MHz, audio on 71.75
=== gap here for air navigation and remote control stations 72-76MHz ===
Channel 5: 76-82MHz, audio on 81.75
Channel 6: 82-88MHz, audio on 87.75
=== gap here for FM radio, ham radio, aircraft communications, military, NOAA weather radio, two-way radio, and other services 88-174MHz ===
Channel 7: 174-180MHz, audio on 179.75
=== and it went up from here in 6MHz steps up to: ===
Channel 13: 210-216MHz, audio on 215.75
There's another gap between 216 and 470Mhz, then channel 14 at 470-476 with audio at 475.75, and it goes up in 6MHz steps from there.
Digital uses the same channel frequencies -- a digital station on RF channel 13 occupies the spectrum between 210-216MHz. But there's no discernable audio carrier, there's simply a digital signal filling the entire chunk of spectrum.
[0] To be literal, the audio was transmitted 4.5MHz above the video. The video was transmitted 1.25MHz above the bottom of the channel - for channel 2, on 55.25MHz. The audio was then transmitted 4.5MHz above that, on 59.75. Many stations were required by the FCC to operate 10KHz "off-frequency" to reduce the visibility of co-channel interference. Most analog receivers used an "intercarrier sound" circuit which mixed the video and audio signals to yield a 4.5MHz "intermediate frequency" - for this reason it was important the 4.5MHz difference between sound and picture signals be accurate. So if the video was, say, 10KHz high, then the audio had to be 10KHz high as well.
To make a long story short, the audio of a channel 6 station might actually have been on 87.74 or 87.76 instead of 87.75. FM receivers couldn't tell the difference.
Much appreciated, w9wi !
Although I managed, happenstancually, to get a few good TV catches, I was never much into TV DXing. (Hardly watch it at all, for the matter of that).
But of you folks don't mind another question or two ....... ?
Somewhere around here is a Hammarlund that's fallen out of use. The last thing I remember using it for -- they're built sturdy -- was when I couldn't find cinderblocks to support a car wheel during brake work. The radio tunes up to 54 mHz. I suppose I could've tune it as far as it'll go, and 'bandspread'ed the rest of the way to get some Channel 2 audio .... maybe even taking a screwdriver to a capacitor to do it, the way I was told a GE SR II could be adjusted to tune the X-band .....
Anyways ....
Does there exist some cutoff point -- some crucial frequency -- after which stations no longer bounce off the ionosphere?
Perhaps asking it another way : At what frequency does line-of-sight reception take over? Or isn't it a matter of frequency at all but just financial factors at play?
Lastly, I'd been told that an FM signal, if it possibly could be filled with some sort of visible dye, would resemble a giant, levitating wafer (and that a dye-filled AM omni signal would resemble a hemisphere). It would appear logical that the audio signal of television stations, back in analog days, would resemble the FM wafer, no?
*If* that last is the case, what shape would the television video signal take? The same? Or do I have something 'sdrawkcab' here, hi ?
Although I managed, happenstancually, to get a few good TV catches, I was never much into TV DXing. (Hardly watch it at all, for the matter of that).
But of you folks don't mind another question or two ....... ?
Somewhere around here is a Hammarlund that's fallen out of use. The last thing I remember using it for -- they're built sturdy -- was when I couldn't find cinderblocks to support a car wheel during brake work. The radio tunes up to 54 mHz. I suppose I could've tune it as far as it'll go, and 'bandspread'ed the rest of the way to get some Channel 2 audio .... maybe even taking a screwdriver to a capacitor to do it, the way I was told a GE SR II could be adjusted to tune the X-band .....
Anyways ....
Does there exist some cutoff point -- some crucial frequency -- after which stations no longer bounce off the ionosphere?
Perhaps asking it another way : At what frequency does line-of-sight reception take over? Or isn't it a matter of frequency at all but just financial factors at play?
Lastly, I'd been told that an FM signal, if it possibly could be filled with some sort of visible dye, would resemble a giant, levitating wafer (and that a dye-filled AM omni signal would resemble a hemisphere). It would appear logical that the audio signal of television stations, back in analog days, would resemble the FM wafer, no?
*If* that last is the case, what shape would the television video signal take? The same? Or do I have something 'sdrawkcab' here, hi ?
w9wi said:
I have heard 88.7 FM which is KTCU. On 6Steve Green NEPA said:
I could get WPSD NBC 6 in Paducah, KY on 87.7 in NW TN, KY, the MO bootheel, and Southern IL.
Steve Green NEPA said:
Hard to say. I strongly suspect you could have got it high enough to get the channel 2 video signal at 55.25, but getting the audio at 59.75 would have been a pretty difficult task.
It's a matter of frequency.
Ionospheric propagation becomes much less common with increasing frequency. It has been reported (sporadic-E) as high as 222MHz. (which would include TV channel 13) Despite hams and DXers looking for it, at least half of years no such propagation is reported above 175MHz.
I suppose meteor-scatter could be argued to be a form of ionospheric propagation. It has been reported at 432MHz, but it's VERY rare at that kind of frequency.
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snoqualmie7 said:
anotherguy said:
All analog TV-6 stations' audio could be received on 87.75. (on most radios 87.7 and 87.9 are close enough...)
The FCC rule was that the audio power of an analog TV station was limited to 22% of visual power. Stations could use any lower figure; 10% was very common. The visual power limit for channel 6 was 100kw, and the same antenna was used to transmit both the audio and video signals.
So a typical analog TV-6 audio facility was 10kw ERP at about 1,000 feet or so -- roughly equivalent to a Class B FM station. Take away some coverage because the TV sound transmitters were modulated only 33% as far as a FM radio was concerned.
A station in Albany, New York which had been analog channel 6 and switched to digital channel 6 left their analog audio transmitter on the air for about 2 months post-transition. Turns out they didn't have FCC authorization to do so, and ended up turning off the analog signal.
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