You are right Neil, that "half-a-watt" sounds questionable, and to echo what you discussed I also have noticed that people sometimes "round up" the numbers.
For example a lot of part 15 websites say they transmit "100 milliWatts," an obvious over-statement.
The spokesperson for KOLD might have been giving a sketchy estimate of the power, but our problem as engineers is that we do not know the precise facts if we are left guessing this way.
Maybe we could say, "Broadcasting with almost One Full Watt."
I assumed it was Inaccurate reporting and have seen such statements before ..
For example a lot of part 15 websites say they transmit "100 milliWatts," an obvious over-statement.
Uh.. I thought "100 milliwatts" was correct.
Part 15 AM BCB allows up to 100 milliwatts INPUT to the final stage of the transmitter...not output. Using Ohms Law, that's volts times amps equals watts or similar extrapolation of formulas.
Thank you Marshall (Just me showing my lack technical knowledge). So what would that translate to as being our actual broadcast output power?
So what would that translate to as being our actual broadcast output power?
That would depend on the efficiency of the final amplifier. There are amplifier classes which have theoretical efficiencies of 70 to 100% but a typical part 15 AM transmitter will have less. I have measured two common transmitters' efficiencies at 30% and 6%.
What "carries the mail" though is the power radiated by the antenna which can be microwatts typically.
Note to Carl: I had a classmate in engineering college who, even in our senior year, confused milli and mega. He would probably brag about a final power input of 100 million watts.
Neil
I printed some stationary once where I added the powers of all my transmitters and expressed the total power in micro-watts or maybe nano-watts. It was a giant looking number.
Oh, and part of the trick was to make the word "micro" very tiny, and the word "Watts" quite large.
It's possible to calculate approximate radiated power from field strength readings in FCC NOUOs. Ken Cartwright's main transmitter, for example, was producing around 3 mW, but it was on a radiating 40-foot metal tower. A ground-level transmitter would produce up to maybe a couple hundred microwatts, but definitely a lot less than one milliwatt.
Did we ever find out if there was actually any interference from KENC's signals? Or was it just heard where someone didn't want it?
Hey guys, I think you might find this interesting:
If you recall, I had mentioned that I had sent an email to KOLD inquiring about what had become of his plans about covering Lincoln Nebraska and the surrounding areas with several Rangemasters...
Well I received an email back to today and thought you might be interested. It's very brief, and I would have liked to hear more details, but all in all, his progress sounds like good news to me.
So here is a copy of that email for your curiosities to savor....
===============================================
Friday, February 11, 2011 4:40 PM
Subject: Re: KOLD1710 AM
We are nearing a completion phase where we will have all transmitters up in Lincoln and elsewhere. We use Rangemasters. There is a lot to be learned from grounding, wiring, etc.
Additionally, though the FCC in DC told us 1710 was legal, apparently it is legal only to 1700 so we will be changing frequencies before long.
Best of luck to you and your endeavor.
Barry Reutzel
--- On Wed, 2/2/11, Richard Powers wrote:
From: Richard Powers
Subject: KOLD1710 AM
To: [email protected]
Date: Wednesday, February 2, 2011, 9:24 AM
Hello Mr.DeCamp,
I was reading several intriquing articles from December 2009 to June 2010 concerning your starting of a low power on-air radio station in your home of Lincon, and using multiple transmitters to cover surrounding areas.
But after June I can't find any more info on your venture, and your website makes no mention of it at all.
I'm very interested to hear what became it, because I am underway in doing something similar (on a much smaller scale) here my small 2 mile hometown of Tybee Island, Georgia.....
..... So I'm inquiring on what happened with your station. Are you now only broadcasting on the internet? - or is there also on-air broadcasting going on there in Lincon?
I appreciate any time you would take in responding to me about this.
Best of everything to you,
Richard Powers
[email protected]
=================================================
RichPowers
You are a great value to this discussion group. Many thanks for seeking and sharing this bit of information about KOLD.
The agent claimed that there was never a complaint. He said that the inspection was inspired by a newspaper article about KENC. The local AM station in town, where Ken Cartwright is now a partner, is suspected of being the complainant, however.
I recall reading something to confirm that, I beleive it was in one of their local online papers. If The licenced station had a part in it, is probally one of those things that will never be known for sure.