If someone at the top of the Empire State Building used an I-trip.....

[BMR]

It's a very silly holiday thread this one....

If someone at the top of the Empire State Building had a I-trip, how far away (if at all) would you be able to hear it with a decent reciever and aerial?

Since this is a daft thread anyway, let's pretend all other stations were off the air... and for extra daftness, there are no other tall buildings in the way........

 

[spunker88]

The low power output of these kills the signal long before you leave is line of sight. I put a similar FM transmitter in a 2 story window and found that the signal faded while I still had a perfect view of the window a couple hundred feet away.

Chances are you wouldn't be able to hear the thing at all once you got to the bottom. Im not sure what the ERP is on a FM transmitter but I imagine its only a small fraction of a watt.

 

[stormy01]

In college I had an FM wireless microphone from Olson Electronics (anyone remember them?) that I modified to connect to a Shure mixer and I increased the battery voltage from the 2 AA batteries it was designed for to a 12-volt lantern battery and used a 10' antenna (6" supplied) in my 9th floor dorm window. The range was at least 1500 feet. It was fun driving around parts of the campus listening to my own private radio "station" There was the university station on a nearby dorm tower that operated with about 2kW ERP at the time (less than 300 feet away) and a very strong 50kW ERP local (less than 5 miles away), that caused some problems, but not like more than 10 stations from ESB or 4 Times Square would cause in terms of intermod, "white noise" and receiver desensing.

The typical power output of these devices is likely to be 10 milliwatts of less, so I agree with Spunker that your signal would be long gone before you could hear it on the ground or across to another building (unless maybe it was right across the street) If you really want to try this, try a really tall hill out in the countryside away from any strong FM stations. You'll get much better results, though the really low power will limit the range anyway. Light-of-sight alone won't help without enough power to reach the intended distance.

 

[spunker88]

In college I had an FM wireless microphone from Olson Electronics (anyone remember them?) that I modified to connect to a Shure mixer and I increased the battery voltage from the 2 AA batteries it was designed for to a 12-volt lantern battery and used a 10' antenna (6" supplied) in my 9th floor dorm window. The range was at least 1500 feet. It was fun driving around parts of the campus listening to my own private radio "station" There was the university station on a nearby dorm tower that operated with about 2kW ERP at the time (less than 300 feet away) and a very strong 50kW ERP local (less than 5 miles away), that caused some problems, but not like more than 10 stations from ESB or 4 Times Square would cause in terms of intermod, "white noise" and receiver desensing.

You could do some serious radio jamming with that. I always though how funny it would be to take a FM transmitter on a bus that has an FM radio station playing, sit in the seat closest to the antenna and jam the signal with your own material.

 

[Bongwater]

In college I had an FM wireless microphone from Olson Electronics (anyone remember them?) that I modified to connect to a Shure mixer and I increased the battery voltage from the 2 AA batteries it was designed for to a 12-volt lantern battery and used a 10' antenna (6" supplied) in my 9th floor dorm window. The range was at least 1500 feet. It was fun driving around parts of the campus listening to my own private radio "station" There was the university station on a nearby dorm tower that operated with about 2kW ERP at the time (less than 300 feet away) and a very strong 50kW ERP local (less than 5 miles away), that caused some problems, but not like more than 10 stations from ESB or 4 Times Square would cause in terms of intermod, "white noise" and receiver desensing.

You could do some serious radio jamming with that. I always though how funny it would be to take a FM transmitter on a bus that has an FM radio station playing, sit in the seat closest to the antenna and jam the signal with your own material.

They STILL have buses with FM radios?

 

[stormy01]

You could do some serious radio jamming with that. I always though how funny it would be to take a FM transmitter on a bus that has an FM radio station playing, sit in the seat closest to the antenna and jam the signal with your own material.

My roomate in the dorm figured out how to change the frequency to one of the rock stations listened to on the dorm floor while playing disco music on the rock station's frequency....needless to say, the guys on the floor weren't too enthused, as in WTF! Luckily, they never found out who visited disco on their rock station... (-;

 

[LibertyNT]

They STILL have buses with FM radios?

The Flat-nosed School buses down here in McKinney Have AM/FM Radios on them.
They are usually disconnected, but a few of the smarter drivers figure out they just have to put the fuse back in.

 

[anotherguyTN]

I've kind of done the same thing with my MP3 transmitter putting it on the same frequency as the BBN station in my area (VERY ultra-traditional Christian music) and playing Christian rock.  ;D

 

[K6JHU]

It has just as much to do with the receiver as the transmitter. My HT on low power is 0.5 watts. Standing at Point Loma I had a QSO on 2m FM (144 MHz) using the Mt. Disappointment repeater. Altitude, no obstructions, plus a very good receiver. That is a distance of some 120+ miles. So you can get out some distance with very little wattage.

 

[Steve_Green]

I had one of those Ramsey things. Might've been a Ramsey-10 ; I forget. It was designed to go maybe 150 feet.

Connected with a used 9-volt battery and using a pair of fully extended rabbit ears, standing in a corner of the living room as the antenna (inside, of course), it was set. I put in a casette of music and drove around.

I'm 1540 feet up at the house, near the top of a long ridge. The hill slides down into the town, itself perhaps 1200 feet ASL for the most part, and there rises another parallel ridge past the southern end of the town.

On the car radio, the 'blowtorch' faded almost as soon as I turned the first corner to go into town. I continued anyway, and drove to the Radio Shack to get a new battery. The Shack is in a mall that just happens to occupy part of that next ridge to the south. It's maybe 50 feet higher than my house. While I was on that next hill, the station was back! Weak, but steady. Had to've been an air mile away. (It was either my broadcast or some other station was playing three Chris Rea songs in a row.)

Couldn't get a peep out of it on the next block south from me, and of course couldn't get a thing all the way through the town itself, it being in a broad-bottomed bowl. I thought it was therefore likely that the same 'transmitting setup', using some place in the mall, could be heard at my house -- but wouldn't cover anywhere near the entire mall.

 

[BobOnTheJob]

In college I had an FM wireless microphone from Olson Electronics (anyone remember them?) that I modified to connect to a Shure mixer and I increased the battery voltage from the 2 AA batteries it was designed for to a 12-volt lantern battery and used a 10' antenna (6" supplied) in my 9th floor dorm window. The range was at least 1500 feet. It was fun driving around parts of the campus listening to my own private radio "station" There was the university station on a nearby dorm tower that operated with about 2kW ERP at the time (less than 300 feet away) and a very strong 50kW ERP local (less than 5 miles away), that caused some problems, but not like more than 10 stations from ESB or 4 Times Square would cause in terms of intermod, "white noise" and receiver desensing.

You could do some serious radio jamming with that. I always though how funny it would be to take a FM transmitter on a bus that has an FM radio station playing, sit in the seat closest to the antenna and jam the signal with your own material.

Reminds me of a trick I pulled in the early 80's...people next door were out washing their car (40' away if that). I had an old tube type signal generator with a 30" wire stuck in the BNC connector & set it to the frequency they were listening to (a station about 25 miles distant). I piped NOAA Weather Radio over their car radio for 30 minutes...there was so much beer flowing that they never noticed that the music stopped. Never bothered trying that again...

 

[nd2023]

WQXR's HD transmitter is only about 6 watts, and it can be heard reliably in HD 15 miles away.

 

[Steve_Green]

Somewhat O/T, but someone brought up the jamming aspects .....

Noisy neighbors downstairs in my former NE Philadelphia apartment got a vindictive sample of the 10.7 intermediate frequency jamming on a few occasions. They'd be blasting some of that MTV/Eighties pop from some station high enough on the dial to allow for me to take my own radio (without even having the volume up, naturally) to tune 10.7 lower and drastically reduce the volume on the downstairs station. I'd hear them adjust it back to the nuisance level. After a few seconds, I'd just flip my dial and have them blast themselves out of their socks. I'd hear the thumping of running footsteps and their volume go back down. On and on it went one day for a half an hour. Then I heard someone pounding the 'obviously' faulty radio and they finally shut it off.

My own rig was a $20 Radio Shack AM-FM job, but the whip antenna made for some pretty good directionability.

Physically and mathematically, such electromagnetic vandalism isn't possible if the offending station is on a frequency lower than 98.7. But that leaves half the dial exposed.

Others here will know the exact frequencies used for communications by jets and planes, and why FX DXing on an airplane might get you and your rig confiscated if you're caught. I'd imagine that's a federal offense.

But for, uh, 'domestic' purposes, the 10.7 Null can ensure a form of tranquility for a while.

 

[BRNout]

Physically and mathematically, such electromagnetic vandalism isn't possible if the offending station is on a frequency lower than 98.7.

Ah, not totally true - many of the world band radios out of China will tune down to 76.0 MHz (or even lower - to Russian OIRT FM). which enables you to wreak havoc on the entire band!

Great story Steve - makes me want to find a way to (as James Bond once said) "have a little fun with Mr. Goldfinger" myself......

 

[radiorob2.0]

I did AV services for a seven story hotel convention center back in the 2000's. At the time I had access to a Landmark Part 15 FM transmitter. Just for giggles I obtained a key to a seventh floor room and set up shop. The transmitter was fed with my laptop using Sound Solution for processing. The antenna was a home brewed dipole included with the transmitter stretched out for vertical polarization. Eight stories down in my lower lobby office the signal was clean. Then came the road experiment, nine blocks from the hotel with perfect line of sight the signal was strong. Twelve blocks away the signal was breaking up but still usable. Twenty blocks away there wasn't much left of the signal but it was there.

I did a similar experiment with a Radio Shack simplex repeater, a device that recorded what it received and retransmitted on the same radio. This time I placed a FRS radio with the repeater hooked up through the external mic jacks atop the drop ceiling on the opposite side of the hotel where the FM experiment occurred. While driving I would say "test" into another FRS radio and would hear the other unit atop the drop ceiling repeat the message. I had a good two miles from the hotel where I could hear the message, pretty impressive considering where the test radio was located and the other FRS radio was in a moving car.

 

[dxer720]

SteveGreenPA, I did the same thing in the late 70s in a dorm to "wipe out" the loud stereo from the next room. I used a cheap hand held TV sound radio for my "moments of silence". I went into the lower of the 2 TV bands to deprive them of their 92.1 rock station when they blast it at 5:30 am. They would turn up the volume. I would wait till they were in the bathroom before I would "let 'em have it". They would get in trouble because it took them so long to get back to the volume to turn it down.