I feel a few things need to be addressed for part 15 am to work effectively in today’s harsh environment.
I feel a few things need to be addressed for part 15 am to work effectively in today’s harsh environment.
While i agree there needs to be a change of the rules for part 15 antenna length and possibly grounding, these changes may or may not help our cause if the problem of interference on the am bcb is not addressed as well.
Not only addressed but handled with extreme prejudice.
Today and for the past 10+ years advancements in technology has brought with it more and more interference on the am and sw bands.
In some areas even Fm is affected by noise from several sources.
For example: I subscribe to Road Runner High Speed as well as Time Warner Cable t.v. but with these conveniences come sacrifices, not only my money(lol) but interference on am/fm radio’s.
I know this because we have turned off our services before and the noise was almost non-existent unless you step outside with a walkman or boombox and maybe walk across the street to where the lines go from the pole into the conduits underground.
This noise is everywhere the power lines or cable tv lines follow the roads or is following the property lines of home owners up and down the roads of London,ky.
Also noise from fluorescent lights, digital gas pumps, street lights, leaky cable lines, power lines and much more. These things mentioned above are everywhere. Have you ever tried to to listen to any radio station while parked at a gas station?
Those pumps and lights put off so much hash , listening to a radio is pointless unless you are close to a high powered radio station.
6 years ago when I was heavy into CB Radio i had this complaint about gas stations and dollar stores, the noise blanker on my Grant Xl was worthless, i could transmit but forget receiving.
Something needs to be done to limit or even eliminate this noise now before it get’s so bad that radio is considered useless.
I can remember back when i was in vocational school towards the end of the 80’s and early 90’s i had a 35-in-1 Heathkit setup as a AM Broadcast Station and was transmitting 1/4 mile clearly.
It was on 1610 khz and I listened to it at as a friend of mine let me hear it over his phone, noise back then was limited to the usual suspects, mother nature and the occasional noisy light switch.
The point is, I could hear the signal 1/4 mile away and all i was using was a ground wire attached to the outlet in my room and a Buick car antenna (telescopic kind) on battery power.
My audio source was a tube type Webcor Reel – to – Reel and a make-shift matching transformer.
Just try that in the city these days and see how far it gets you.
I’m not against re-vamping the part 15 rules for am antennas or sorting out the grounding issues, but in order for low powered am to work, the noise needs to be removed or controlled more closely.
I would think this would fall under Spurious Emissions and if not, then it should be considered that from now on.
Yeah, years of research,
Yeah, years of research, design and experimentation only to be flushed down the drain while the FCC pays all its attention to all things digital and pretty.
The Largest Noise Source…
Even though decades of trying to legislate good engineering practice to enhance radio wave propagation, the fact remains setting a radio propagation standard in the FCC rules IS a moving target.
The largest noise generator in the universe happens to be the Sun. As the solar sun spot cycles oscillate back and forth over the 7 to 11 year periods, noise generated by solar storms and solar activity produce a lot of interference and noise in radio services using AM, double-sideband, single sideband, continuous wave, TV video and to some degree in FM and digital.
The FCC and very bright broadcast propagation consulting engineers have wrestled with these issues for many years. Even now, two well respected broadcast engineering firms are trying to solve the noise problem for AM broadcasters by doing away with the AM broadcast “ratchet rules”.
When we understand how the bands and services actually propagate signals, then when can innovate systems that will overcome the obstacle of noise. And, no, digital does not supply all the answers. If you study HD AM, FM or TV, one discovers that transmission standards are only a very small part of the total picture. Now enters the villain of the receiver and its design. And the final culprit, the counterpoise/ground scheme used by the receiver to listen to a specific signal on a specific frequency. Someone mentioned listening to a high noise level on a CB receiver. I have found most of the noise could be eliminated by a satisfactory earth ground on the antenna and the receiver. Any voltage potential between receiving components in any station can produce all kinds of noise. My guess is, we have much more to learn.
Just a final note: ham radio operators work with AM, CW and single sideband signals all the time with signals smaller than most part 15 operators and with great success. It’s called QRP. And its NOT done with smoke and mirrors (we hope).
Reality Noise
The AM and FM bands are polluted not only by the many noise sources mentioned above, but by DAB (digital audio broadcasting) which have no real-world purpose. We, the low power people, are here because the programming on licensed radio is void of creativity, so why would those stations need more channel space? The fact is they don’t need it and they don’t know what to do with it. If station X is boring with one channel, it can be twice as boring with two. Maybe if enough boredom is broadcast somebody will actually listen. But DAB isn’t selling any HD radios, and who knows what HD means? High definition? That’s television. Besides, FM already has excess capacity because of their sub-carrier bandwidth. Only a small number of lucrative applications have been found for sub-carriers, because the general public isn’t about to buy a special SCA radio, which I think is the right name. According to informed sources (DIYmedia.net) DAB is failing miserably in Europe, and I think the same can be said for America. This would relieve a lot of pressure on stations, radio sales and unwanted noise.