🚀 go-pugleaf

Jeff Liebermann wrote:
> On Sun, 18 Jul 2010 10:31:05 -0700, JC Dill <jcdill.lists@gmail.com>
> wrote:
> 
>> Jeff Liebermann wrote:
>>
>>>> You recall wrong.  Circa 1992-1994 you could buy a 3 watt bag phone. 
>>>> I'm told that circa 1990 you could buy a 5 watt bag phone.
>>> My memory isn't perfect, but I don't recall any 5 watt bag phones.
>>> There would have been considerable advertising value to offering the
>>> most "powerful" phone.  
>> My recollection of the conversation I had at the time, was that when 
>> car/bag phones were first offered in the late 1980s/early 1990s, some 
>> were 3 watt, some were 5 watt.  The 5 watt ones ate batteries and 
>> weren't as popular with most users for that reason, then the industry 
>> (or the government) decided that the phones should be capped at 3 watts 
>> and the 5 watt models were discontinued.  I was told that there were 
>> long-haul truckers who used the 5 watt phones to get coverage in rural 
>> areas where 3 watt phones couldn't reach the distant towers.  By the 
>> time I was shopping (circa 1992), I was told the 5 watt phones had been 
>> discontinued for some time (more than 1 year) and if I wanted one I 
>> would have to try to find it on the second-hand market (pre-craigslist).
>>
>> jc
> 
> I think you might be mixing technologies.  During the 1980's, long
> haul truckers were using IMTS phones (and CB).  

In the early 1990s, some were starting to use cell phones.

That's because the
> range of an IMTS base station was 20-50 miles or more and located to
> cover the highways.  Also cellular had huge gaps in rural coverage.
> The down side was that the channels were few and crowded.  There may
> have been some small 5 watt radios, but most were 25 watts.
> 
> The Motorola Pulsar III IMTS control head looked exactly like the
> later bag phone handset.  See photo near the bottom of:
> <http://www.wb6nvh.com/Carphone.htm>
> Pac Hell stopped providing IMTS service in 1995, but smaller rural
> RCC's (radio common carriers) continues to operate through about 2005.
> 
> Checking the FCC rules at:
> <http://www.hallikainen.com/FccRules/2010/22/913/>
> it proclaims:
>    The ERP of mobile transmitters and auxiliary test transmitters
>    must not exceed 7 Watts.
> ERP (or EIRP) is "effective radiated power" which includes the gain of
> the antenna.  The traditional AMPS mobile antenna has about 4dBi gain
> or 2.5 times the xmitter power output equals the EIRP.  
>    7 watts / 2.5 = 2.8 watts
> which is where the 3 watt limit came from.  It might have been
> possible to legally sell a 5 watt mobile phone, but could only be
> supplied with a small 1/4 wave vertical monopole antenna.
> 
> Going back as far as possible to 1997:
> <http://louise.hallikainen.org/FCC/FccRules/1997/22/913/>
> This rule has not changed.

I was told the rule changed "a few years" prior to my buying my first 
cell phone, the 3 watt bag phone I bought circa 1992 from Cellular One.

jc