AT&T shuts down 800 MHz GSM service in Oakland because of interferencewith the police radio system.

<http://news.cnet.com/8301-1035_3-57497517-94/at-t-cuts-frequency-on-cell-towers-that-jammed-police-radios/>

"sms88" <scharf.steven@geemail.com> wrote in message
news:k1101t$u7p$1@dont-email.me...
> <http://news.cnet.com/8301-1035_3-57497517-94/at-t-cuts-frequency-on-cell-towers-that-jammed-police-radios/>

It's a well known and documented problem not only for 800 Mhz system. Often
the problem is not caused by the cell tower but can and has been traced to
the design of the public service radios themselves.

On 8/21/2012 4:12 PM, NotMe wrote:
> "sms88" <scharf.steven@geemail.com> wrote in message
> news:k1101t$u7p$1@dont-email.me...
>> <http://news.cnet.com/8301-1035_3-57497517-94/at-t-cuts-frequency-on-cell-towers-that-jammed-police-radios/>
>
> It's a well known and documented problem not only for 800 Mhz system. Often
> the problem is not caused by the cell tower but can and has been traced to
> the design of the public service radios themselves.

Hmm, the FCC investigated this and found the source of interference.
Whether AT&T was doing something wrong, or the public service radio has
priority when there is interference, is not clear.

"sms88" <scharf.steven@geemail.com> wrote in message
news:k1160j$37p$1@dont-email.me...
>
>
> On 8/21/2012 4:12 PM, NotMe wrote:
>> "sms88" <scharf.steven@geemail.com> wrote in message
>> news:k1101t$u7p$1@dont-email.me...
>>> <http://news.cnet.com/8301-1035_3-57497517-94/at-t-cuts-frequency-on-cell-towers-that-jammed-police-radios/>
>>
>> It's a well known and documented problem not only for 800 Mhz system.
>> Often
>> the problem is not caused by the cell tower but can and has been traced
>> to
>> the design of the public service radios themselves.
>
> Hmm, the FCC investigated this and found the source of interference.
> Whether AT&T was doing something wrong, or the public service radio has
> priority when there is interference, is not clear.

CTIA did an extensive study on the problem in the '90s, I'll see if I can
find my copy of the report.

In any case it's rare where Public Safety has had to bear the burden of the
fix.

On Tue, 21 Aug 2012 23:47:21 -0500, "NotMe" <me@privacy.net> wrote:

>
>"sms88" <scharf.steven@geemail.com> wrote in message
>news:k1160j$37p$1@dont-email.me...
>>
>>
>> On 8/21/2012 4:12 PM, NotMe wrote:
>>> "sms88" <scharf.steven@geemail.com> wrote in message
>>> news:k1101t$u7p$1@dont-email.me...
>>>> <http://news.cnet.com/8301-1035_3-57497517-94/at-t-cuts-frequency-on-cell-towers-that-jammed-police-radios/>
>>>
>>> It's a well known and documented problem not only for 800 Mhz system.
>>> Often
>>> the problem is not caused by the cell tower but can and has been traced
>>> to
>>> the design of the public service radios themselves.
>>
>> Hmm, the FCC investigated this and found the source of interference.
>> Whether AT&T was doing something wrong, or the public service radio has
>> priority when there is interference, is not clear.
>
>CTIA did an extensive study on the problem in the '90s, I'll see if I can
>find my copy of the report.
>
>In any case it's rare where Public Safety has had to bear the burden of the
>fix.

Some years ago several neighbors complained to the FCC that a ham was
causing interference to their TV sets. An investigation found that the
ham's gear was clean but that the TV sets had insufficient adjacent
channel interference capability to suppress the ham's strong signal.
Though the ham was not at fault he was given quiet hours (ordered not
to transmit) during peak TV viewing time.

Perhaps this is a similar situation. I doubt the cell tower is
transmitting on the wrong frequency (public service). More likely the
public service gear can't handle the strong adjacent frequency signal.
It's probably easier to shut off a cell tower than to replace all the
current public service radios. From a public safety standpoint that
makes sense. However time will likely solve the problem as the PS
units are eventually upgraded or changed out.

On Aug 22, 3:29*pm, AaronL <5678sd...@fakeemail.com> wrote:
> On Tue, 21 Aug 2012 23:47:21 -0500, "NotMe" <m...@privacy.net> wrote:
>
> >"sms88" <scharf.ste...@geemail.com> wrote in message
> >news:k1160j$37p$1@dont-email.me...
>
> >> On 8/21/2012 4:12 PM, NotMe wrote:
> >>> "sms88" <scharf.ste...@geemail.com> wrote in message
> >>>news:k1101t$u7p$1@dont-email.me...
> >>>> <http://news.cnet.com/8301-1035_3-57497517-94/at-t-cuts-frequency-on-c...>
>
> >>> It's a well known and documented problem not only for 800 Mhz system.
> >>> Often
> >>> the problem is not caused by the cell tower but can and has been traced
> >>> to
> >>> the design of the public service radios themselves.
>
> >> Hmm, the FCC investigated this and found the source of interference.
> >> Whether AT&T was doing something wrong, or the public service radio has
> >> priority when there is interference, is not clear.
>
> >CTIA did an extensive study on the problem in the '90s, *I'll see if Ican
> >find my copy of the report.
>
> >In any case it's rare where Public Safety has had to bear the burden of the
> >fix.
>
> Some years ago several neighbors complained to the FCC that a ham was
> causing interference to their TV sets. An investigation found that the
> ham's gear was clean but that the TV sets had insufficient adjacent
> channel interference capability to suppress the ham's strong signal.
> Though the ham was not at fault he was given quiet hours (ordered not
> to transmit) during peak TV viewing time.

Not sure what band that ham was transmitting on. In high school a ham
moved into the neighborhood whose CW could be heard on the TV. I
bought a high pass filter made by Zenith and put it in series with the
antenna input -- no more problem.


>
> Perhaps this is a similar situation. I doubt the cell tower is
> transmitting on the wrong frequency (public service). More likely the
> public service gear can't handle the strong adjacent frequency signal.
> It's probably easier to shut off a cell tower than to replace all the
> current public service radios. From a public safety standpoint that
> makes sense. However time will likely solve the problem as the PS
> units are eventually upgraded or changed out.

All we read about is problems with public safety radios, not solutions.

In article <39ma38dps1h03mm13hn67pbctg6sn4lerk@4ax.com>,
AaronL <5678sd834@fakeemail.com> wrote:

[unneeded quotage deleted]


>Perhaps this is a similar situation. I doubt the cell tower is
>transmitting on the wrong frequency (public service). More likely the
>public service gear can't handle the strong adjacent frequency signal.
>It's probably easier to shut off a cell tower than to replace all the
>current public service radios. From a public safety standpoint that
>makes sense. However time will likely solve the problem as the PS
>units are eventually upgraded or changed out.

Hate to break it to you, but this *is* the upgraded PS system.
The problem started when the new units were installed last year.


Patty

On Wed, 22 Aug 2012 16:31:56 -0700 (PDT), spamtrap1888
<spamtrap1888@gmail.com> wrote:

>On Aug 22, 3:29*pm, AaronL <5678sd...@fakeemail.com> wrote:

>> Some years ago several neighbors complained to the FCC that a ham was
>> causing interference to their TV sets. An investigation found that the
>> ham's gear was clean but that the TV sets had insufficient adjacent
>> channel interference capability to suppress the ham's strong signal.
>> Though the ham was not at fault he was given quiet hours (ordered not
>> to transmit) during peak TV viewing time.
>
>Not sure what band that ham was transmitting on.

The ham in this example was on 6 meters (50-54 MHz). Analog TV channel
2 (at that time) started at 54 MHz. As I said that was some years ago.
Maybe the new digital TV system has changed things.

>In high school a ham
>moved into the neighborhood whose CW could be heard on the TV. I
>bought a high pass filter made by Zenith and put it in series with the
>antenna input -- no more problem.

CW is normally used on the HF ham bands, the highest frequency likely
used at 28 MHz. A high pass filter will work better in this situation
since the separation of some 20+ MHz is much easier to filter than
virtually no separation.

In some circumstances with the ham running the legal limit (1KW) TV
interference can be caused by direct self-rectification in the TV's
audio and IF circuits (no antenna needed). That can be very difficult
to filter.

Again even though the ham is not technically at fault, the FCC might
still order him silent. Most hams though, if they know what is good
for them, will work with their neighbors to solve any problems before
the authorities are brought in.

On 23 Aug 2012 01:41:21 GMT, Patty Winter <patty1@wintertime.com>
wrote:

>
>In article <39ma38dps1h03mm13hn67pbctg6sn4lerk@4ax.com>,
>AaronL <5678sd834@fakeemail.com> wrote:
>
>[unneeded quotage deleted]
>
>
>>Perhaps this is a similar situation. I doubt the cell tower is
>>transmitting on the wrong frequency (public service). More likely the
>>public service gear can't handle the strong adjacent frequency signal.
>>It's probably easier to shut off a cell tower than to replace all the
>>current public service radios. From a public safety standpoint that
>>makes sense. However time will likely solve the problem as the PS
>>units are eventually upgraded or changed out.
>
>Hate to break it to you, but this *is* the upgraded PS system.
>The problem started when the new units were installed last year.

I suppose like most electronics when you buy it it is already
obsolete. In this case I'm sure the problem will eventually be solved.
There's too much money riding on the unused frequency spectrum to
think otherwise.

"Patty Winter" <patty1@wintertime.com> wrote in message
news:50358a41$0$70377$742ec2ed@news.sonic.net...
>
> In article <39ma38dps1h03mm13hn67pbctg6sn4lerk@4ax.com>,
> AaronL <5678sd834@fakeemail.com> wrote:
>
> [unneeded quotage deleted]
>
>
>>Perhaps this is a similar situation. I doubt the cell tower is
>>transmitting on the wrong frequency (public service). More likely the
>>public service gear can't handle the strong adjacent frequency signal.
>>It's probably easier to shut off a cell tower than to replace all the
>>current public service radios. From a public safety standpoint that
>>makes sense. However time will likely solve the problem as the PS
>>units are eventually upgraded or changed out.
>
> Hate to break it to you, but this *is* the upgraded PS system.
> The problem started when the new units were installed last year.

Who is the manufacturer of the equipment?

"NotMe" <me@privacy.net> wrote in message news:k146gs$u41$1@dont-email.me...
> "Patty Winter" <patty1@wintertime.com> wrote in message
> news:50358a41$0$70377$742ec2ed@news.sonic.net...
>>
>> In article <39ma38dps1h03mm13hn67pbctg6sn4lerk@4ax.com>,
>> AaronL <5678sd834@fakeemail.com> wrote:
>>
>> [unneeded quotage deleted]
>>
>>
>>>Perhaps this is a similar situation. I doubt the cell tower is
>>>transmitting on the wrong frequency (public service). More likely the
>>>public service gear can't handle the strong adjacent frequency signal.
>>>It's probably easier to shut off a cell tower than to replace all the
>>>current public service radios. From a public safety standpoint that
>>>makes sense. However time will likely solve the problem as the PS
>>>units are eventually upgraded or changed out.
>>
>> Hate to break it to you, but this *is* the upgraded PS system.
>> The problem started when the new units were installed last year.
>
> Who is the manufacturer of the equipment?

Additional questions. Are there existing unit on the system that work and
who is that manufacture?