What exactly does that phrase mean? "effective service range"?..
Back in 1978 an indepth study was released that looked into several methods which could be utilized during times of emergency to provide the public information. The conclusions came down to using TIS and CBs, but Part 15 also was considered:
"In addition to TIS systems as defined by FCC's Rules and Regulations, similar devices can be operated under Part 15 of the the Rules and Regulations without licences if their output is restricted to 100 milliwatts. These unlicensed stations have an advantage over TIS systems because they can be operated on any frequency between 510 and 1,600 kHz. They can be operated with conventional or cable antennas. Their effective range is under 0.8 kiometer (0.5 mile) with a monopole antenna. Their short range makes them unsuitable for general emergency use." http://https//www.ncjrs.gov/pdffiles1/Digitization/47617NCJRS.pdf
I wish I had saved every reference I had come across in official documents that had provided effective service range estimates for part 15 AM transmitters (withon the last 40 years), because none of them say anything so ridiculuos as the FCCs public notice stating 200 feet.Even the FCC's own John Reed (who had wrote the Part15 rules) said concerning that public notice while in correspondence with R Fry:
"..Yes, I know that a Public Notice was released saying that unlicensed AM and FM transmitters have 200 feet of range... same applies to range estimates for operation in the AM band. (That same Public Notice also incorrectly stated that you can have 50 mW ERP in the AM band and 10 uW in the FM band..) This is why our rules do not specify a range - it's a relative term that is completely dependent on the environment.. The non-technical author of the notice should have checked with the engineers before writing this. Note that the numbers in this Public Notice are not binding - the equipment must meet the standards in the actual regulations.).."Source: http://www.radiodiscussions.com/showthread.php?540838-FCC-s-John-Reed-Co...
I have been researching in the last week or two trying to track down what part15 transmitters where being manufactured and certified under the alternative rule during the early 1970's (which by the way havent found any yet), that had concerned the FCC so much back then, and though I haven't found what I was looking for, a lot of interesting bits like this have been revealed. Most of this I wrote anout in a couple threads at HB, but I mentioned the same here and at ALPB when I was beginning, but didn't it didn't seem to generate much interest.
Anyway, none of what I found has been much help, but it is interesting to note that the ground lead rule was not wrote into the rules, nor did the FCC propose to eliminate 15.219 from the rules for manufactured units until the studies and considerations of creating a TIS classification had begun.. The time periods corelate exactly.
In the 80 years of part 15, this was the only time the rules underwent any major modification (other than adding the alternate rule being added in 1957). Therefore it's hard not to conclude the TIS station creation somehow directly influenced the ground lead rule being created for part 15.
Also of note is that certain documents stated that prior to the creation of a new TIS classification in 1978, all TIS stations operated under part 15.. However, I couldn't find any other documentation to confirm this.. Other documents make it clear that prior to 1976 only some TIS stations operated part 15, but most of them operated under FCC expiremental licences going back as far as the 1940's.. The story goes on and on.. but I still haven't found what I was looking for, which is manufactured part 15 transmitters in the early 1970's..
Someone, somewhere, must have a lead to follow, cause I have hit a dead end.
Well, looks like I compleately drifted the topic of my own post!