Licensed or Part 15, those are the two choices
 
 
In a message dated 11/1/2010 11:24:41 P.M. Eastern Daylight Time,  
jsantee@............ writes:

"But  this RFI stuff is not enforced unless it interferes with important  
stuff"

RFI is not as simple as "off or on". The issue can be quite  complicated. 
The 
consumer electronics industry generally tries to get away  with the 
cheapest 
stuff possible. If you remember the Radio Shack TRS-80  computer of the 
1980's aka "Trash 80". This was one of the biggest  generators of RFI ever 
to 
hit the consumer market. Then there are some  products that are 
electronically "naturally noisy" and there is not much  you can do about it.

The commercial two way radio market this is much  more regulated and built 
to 
little higher standard. But you are dealing  with consumer electronics in 
nearby homes that are built to the cheapest  standards that will allow 
unwanted interference in the system and then  home owners demand the 
commercial user clean up the mess that the home  owner actually created 
themselves. If you have twenty feet of speaker wire  from your home stereo 
running near the front of your home this will act  like a receiving antenna 
and sometimes pick up a two way radio be used in  a car driving near by. If 
you have an external FM antenna with a cheap  consumer receiver you can 
expect that now and then you are going to get  hit with "10-4 good buddy"

In the 1980's there was a big push to get  the consumer electronics 
industry 
to better engineer their disposable junk  to prevent interference from 
legitimate amateur and commercial users. At  the time it was estimated that 
it would have cost about a few cents extra  per radio. The industry raised 
hell and nothing was done.

Getting  into the commercial stuff. When you have a large radio site with 
multiple  antennas, radios, circulators and duplexers you are going to have 
 
problems. This is why setting up these systems can be an engineering  
nightmare. But if done correctly interference within the site will be  
minimal. The problem being nearby by with cheap consumer radios that have  
no 
filters. This could be hell on earth.

When all is said and done  it is the end users to be aware of their own 
problems and take prudent  action to add by pass capacitors, ferrite beads, 
and be careful of where  they run the speakers and telephone wires. If 
there 
is an illegal radio  interference issue then this has been be dealt with, 
but 
when complaining  you have to be sure your own operation is technically up 
to  
standard.

Here is one self imposed RFI issue: I knew of an  electrician who had the 
job 
to run the housing wiring and speaker wiring  for an upscale home. The 
idiot 
ran the speaker wiring right next to the AC  lines. The 60 Hz hum made the 
high end entertainment system was  useless.

I have spent a lot of time dealing with this. This issue gets  real ugly 
very 
quickly. I like discussions about this issue, the more  people know the 
better people can react and solve  problems.

Jim

__________________________________________________________

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To leave this list email  PSNLIST-REQUEST@.............. with 
the body of the message (first line  only): unsubscribe
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Licensed or Part 15, those are the two choices
 

In a message dated 11/1/2010 11:24:41 P.M. Eastern Daylight Time,=20
jsantee@............ writes:
"But=20
  this RFI stuff is not enforced unless it interferes with important=20
  
stuff"

RFI is not as simple as "off or on". The issue can be=
 quite=20
  complicated. The 
consumer electronics industry generally tries to ge=
t away=20
  with the cheapest 
stuff possible. If you remember the Radio Shack TR=
S-80=20
  computer of the 
1980's aka "Trash 80". This was one of the biggest=
=20
  generators of RFI ever to 
hit the consumer market. Then there are so=
me=20
  products that are 
electronically "naturally noisy" and there is not=
 much=20
  you can do about it.

The commercial two way radio market this is=
 much=20
  more regulated and built to 
little higher standard. But you are deal=
ing=20
  with consumer electronics in 
nearby homes that are built to the chea=
pest=20
  standards that will allow 
unwanted interference in the system and th=
en=20
  home owners demand the 
commercial user clean up the mess that the ho=
me=20
  owner actually created 
themselves. If you have twenty feet of speake=
r wire=20
  from your home stereo 
running near the front of your home this will=
 act=20
  like a receiving antenna 
and sometimes pick up a two way radio be us=
ed in=20
  a car driving near by. If 
you have an external FM antenna with a che=
ap=20
  consumer receiver you can 
expect that now and then you are going to=
 get=20
  hit with "10-4 good buddy"

In the 1980's there was a big push to=
 get=20
  the consumer electronics industry 
to better engineer their disposabl=
e junk=20
  to prevent interference from 
legitimate amateur and commercial users=
.. At=20
  the time it was estimated that 
it would have cost about a few cents=
 extra=20
  per radio. The industry raised 
hell and nothing was done.

Get=
ting=20
  into the commercial stuff. When you have a large radio site with 
mul=
tiple=20
  antennas, radios, circulators and duplexers you are going to have=20
  
problems. This is why setting up these systems can be an engineering=
=20
  
nightmare. But if done correctly interference within the site will=
 be=20
  
minimal. The problem being nearby by with cheap consumer radios that=
 have=20
  no 
filters. This could be hell on earth.

When all is said and=
 done=20
  it is the end users to be aware of their own 
problems and take prude=
nt=20
  action to add by pass capacitors, ferrite beads, 
and be careful of=
 where=20
  they run the speakers and telephone wires. If there 
is an illegal ra=
dio=20
  interference issue then this has been be dealt with, but 
when compla=
ining=20
  you have to be sure your own operation is technically up to=20
  
standard.

Here is one self imposed RFI issue: I knew of an=20
  electrician who had the job 
to run the housing wiring and speaker wi=
ring=20
  for an upscale home. The idiot 
ran the speaker wiring right next to=
 the AC=20
  lines. The 60 Hz hum made the 
high end entertainment system was=20
  useless.

I have spent a lot of time dealing with this. This issue=
 gets=20
  real ugly very 
quickly. I like discussions about this issue, the mor=
e=20
  people know the 
better people can react and solve=20
  problems.

Jim

____________________________________________=
______________

Public=20
  Seismic Network Mailing List (PSNLIST)

To leave this list email=
=20
  PSNLIST-REQUEST@.............. with 
the body of the message (first=
 line=20
  only): unsubscribe
See http://www.seismicnet.com/maillist.html for mo=
re=20
  information.