What is 868mhz - Phone Conversations??

What is 868mhz - Phone Conversations??

Post by Zeke Setze » Tue, 21 Mar 2000 04:00:00

The scanner in my car is hitting some frequencies like 868.7875 and
a couple others in the 860's which appear to be phone conversations, I
think one sided, often more than one at once.  But I've read that
cordless 900mhz phones are 900-928 and old cordless are in the 40's, so
what am I hearing?

I know that frequency is used by some trunking systems but this isn't a
trunking scanner and these people are clearly just casually talking to
each other, usually female - that's what got me paying attention because
most of the police frequncies (sorry that's just the way it is here in
Central PA) are male.  It seems to disappear quickly as I drive by the
source and it is heavy in residential areas.

Anybody know?  Thanks!

Sent via Deja.com http://www.deja.com/
Before you buy.

 
 
 

What is 868mhz - Phone Conversations??

Post by Andy » Tue, 21 Mar 2000 04:00:00


Mobile phones have a 45 Mhz split, so youmust ahve been near someone using a
handset.


Quote:> The scanner in my car is hitting some frequencies like 868.7875 and
> a couple others in the 860's which appear to be phone conversations, I
> think one sided, often more than one at once.  But I've read that
> cordless 900mhz phones are 900-928 and old cordless are in the 40's, so
> what am I hearing?

> I know that frequency is used by some trunking systems but this isn't a
> trunking scanner and these people are clearly just casually talking to
> each other, usually female - that's what got me paying attention because
> most of the police frequncies (sorry that's just the way it is here in
> Central PA) are male.  It seems to disappear quickly as I drive by the
> source and it is heavy in residential areas.

> Anybody know?  Thanks!

> Sent via Deja.com http://www.deja.com/
> Before you buy.

 
 
 

What is 868mhz - Phone Conversations??

Post by Rick B » Tue, 21 Mar 2000 04:00:00

Hi Zeke,

You are hearing analog cell phones.

Rick B.


> The scanner in my car is hitting some frequencies like 868.7875 and
> a couple others in the 860's which appear to be phone conversations, I
> think one sided, often more than one at once.  But I've read that
> cordless 900mhz phones are 900-928 and old cordless are in the 40's, so
> what am I hearing?

> I know that frequency is used by some trunking systems but this isn't a
> trunking scanner and these people are clearly just casually talking to
> each other, usually female - that's what got me paying attention because
> most of the police frequncies (sorry that's just the way it is here in
> Central PA) are male.  It seems to disappear quickly as I drive by the
> source and it is heavy in residential areas.

> Anybody know?  Thanks!

> Sent via Deja.com http://www.deja.com/
> Before you buy.

 
 
 

What is 868mhz - Phone Conversations??

Post by David L. Wilso » Thu, 23 Mar 2000 04:00:00


Quote:> Hi Zeke,

> You are hearing analog cell phones.

More precisely, he is hearing one of the cell phone (non-wireline carrier)
towers.  The phone are 45 MHz lower than that.
 
 
 

What is 868mhz - Phone Conversations??

Post by Zeke Setze » Fri, 24 Mar 2000 04:00:00

OK, confirmed, I am hearing images of cells.  How do I know?  Yesterday
I heard "the celluar customer you are calling is out of range".  So now,
legally, I guess I have to stop listening to it :)  Although that's too
bad because that was one of the local police trunk frequencies
(868.7875).  Hear it on 866.4375 also by the way.

Wasn't particularly close to cell towers when I hear these, hear them
most of the way home from work at 5pm.  Must be a scanner bug.  Not
terribly good listening mobile, but stationary you could hear at least
one side of a conversation.  Lots of digital hooey buzzes going on in
the background.

Thanks everyone for their help!



> The scanner in my car is hitting some frequencies like 868.7875 and
> a couple others in the 860's which appear to be phone conversations, I
> think one sided, often more than one at once. But I've read that
> cordless 900mhz phones are 900-928 and old cordless are in the 40's,
so
> what am I hearing?

Sent via Deja.com http://www.deja.com/
Before you buy.
 
 
 

What is 868mhz - Phone Conversations??

Post by Dave Martinda » Fri, 24 Mar 2000 04:00:00


>OK, confirmed, I am hearing images of cells.  How do I know?  Yesterday
>I heard "the celluar customer you are calling is out of range".

That just means that the phone call you were hearing was attempting
to call a cellular customer, not that the side you heard was cellular.

Quote:>So now,
>legally, I guess I have to stop listening to it :)  Although that's too
>bad because that was one of the local police trunk frequencies
>(868.7875).  Hear it on 866.4375 also by the way.

In fact, the tower frequencies for analog cellular start at 869.04 MHz,
and go up to 893.97.  If you're hearing one of those as an image,
your scanner has an awfully low IF frequency.  The mobile (handheld)
frequencies are 45 MHz lower in frequency, so it is plausible to receive
them as an image if your scanner had about a 22 MHz IF - still unusually
low.

Another possibility: apparently the airphones that are used on planes
are allocated frequencies adjacent to the land cellular system.  Maybe
you have been hearing airphone transmissions?

        Dave

 
 
 

What is 868mhz - Phone Conversations??

Post by Zeke Setze » Fri, 24 Mar 2000 04:00:00

That's possible I guess but there are an awful lot of them. Wouldn't
think there would be that many planes in range - no big airport in
Central PA...
Rougly, answers I have received via mail and news have indicated:
Cell Phone 7
Cordless 2
Air Phone 1

Quote:> Another possibility: apparently the airphones that are used on planes
> are allocated frequencies adjacent to the land cellular system. Maybe
> you have been hearing airphone transmissions?

> Dave

Sent via Deja.com http://www.deja.com/
Before you buy.
 
 
 

What is 868mhz - Phone Conversations??

Post by Dave Martinda » Sat, 25 Mar 2000 04:00:00


>That's possible I guess but there are an awful lot of them. Wouldn't
>think there would be that many planes in range - no big airport in
>Central PA...

Ah, but the antennas on the planes are 6 or 7 miles above the surface.
That gives them a range of 100 miles or so, which means the ground
stations are spaced quite far apart.  If you happen to be located
near one of the ground stations, you'll be able to hear one side
of calls going to planes over a very large area.  And the ground
stations will be positioned to hear planes at altitude, not on
the ground, so they don't need to be near any major airport.

        Dave

 
 
 

What is 868mhz - Phone Conversations??

Post by Michael B. Tinsle » Sat, 25 Mar 2000 04:00:00

One thing that didn't get answered here, though, that I am VERY curious
about.  Why is it that sometimes you only hear 1/2 of the conversation and
other times you get both sides?  I am talking about when you are in the
Tower Xmit frequency range.  Do some tower head-ends actually re-xmit the
signal that they get from the mobile unit right back to the mobile unit?
That is the only explanation I can conjure up.  Sometimes you can only hear
the side of the conversation that is going to the mobile unit, and you hear
absolutely nothing from the mobil.  Other times you can hear the mobile unit
just as well as you can the tower.

Or is there some type of feedback path in certain landline phones that cause
the audio coming from the mobile unit to go back to the mobile unit on the
Tower xmit freq?  This has been bugging me for a while, so any help you can
offer is greatly appreciated.

Mike


Quote:> The scanner in my car is hitting some frequencies like 868.7875 and
> a couple others in the 860's which appear to be phone conversations, I
> think one sided, often more than one at once.  But I've read that
> cordless 900mhz phones are 900-928 and old cordless are in the 40's, so
> what am I hearing?

> I know that frequency is used by some trunking systems but this isn't a
> trunking scanner and these people are clearly just casually talking to
> each other, usually female - that's what got me paying attention because
> most of the police frequncies (sorry that's just the way it is here in
> Central PA) are male.  It seems to disappear quickly as I drive by the
> source and it is heavy in residential areas.

> Anybody know?  Thanks!

> Sent via Deja.com http://www.deja.com/
> Before you buy.

 
 
 

What is 868mhz - Phone Conversations??

Post by Michael B. Tinsle » Sun, 26 Mar 2000 04:00:00

I am further curious as to why you would waste GOOD bandwidth and MY time
posting ***like that.  If you don't know the answer or you don't want to
discuss it, then don't say anything.

Let me assuage your curiosity... I want to know the answer.  That's why I
asked.  For your info, I am not in Georgia.

Also, I am curious as to how someone can get a self-righteous,
holier-than-thou attitude.  Must have been your upbringing.

When I need a conscience, I'll turn to Jimminy Cricket... you can kiss off,
Mr. The Real.

Mike




> >One thing that didn't get answered here, though, that I am VERY curious
> >about.

> I'm very curious WHY you'd want to discuss something that is illegal
> for most of the users here, including yourself in Georgia.

> To reply by email, remove the XYZ.

> Lumber Cartel (tinlc) #2063. Spam this account at your own risk.

 
 
 

What is 868mhz - Phone Conversations??

Post by Barrie Shepher » Mon, 27 Mar 2000 04:00:00

Put simply, whether you hear 1 side or both of the conversation depends upon
the termination that the call meets in the phone PSTN system.  If its to an
ordinary phone, or local you often hear both sides because of the side tone
feature of the phones i.e. you are hearing the other side rebroadcast via
the receivers phone / termination.  ISDN and calls to digital phone system
have far better rejection so the cross talk does not occur hence you only
hear one side.

BS


>One thing that didn't get answered here, though, that I am VERY curious
>about.  Why is it that sometimes you only hear 1/2 of the conversation and
>other times you get both sides?  I am talking about when you are in the
>Tower Xmit frequency range.  Do some tower head-ends actually re-xmit the
>signal that they get from the mobile unit right back to the mobile unit?
>That is the only explanation I can conjure up.  Sometimes you can only hear
>the side of the conversation that is going to the mobile unit, and you hear
>absolutely nothing from the mobil.  Other times you can hear the mobile
unit
>just as well as you can the tower.

>Or is there some type of feedback path in certain landline phones that
cause
>the audio coming from the mobile unit to go back to the mobile unit on the
>Tower xmit freq?  This has been bugging me for a while, so any help you can
>offer is greatly appreciated.

>Mike



>> The scanner in my car is hitting some frequencies like 868.7875 and
>> a couple others in the 860's which appear to be phone conversations, I
>> think one sided, often more than one at once.  But I've read that
>> cordless 900mhz phones are 900-928 and old cordless are in the 40's, so
>> what am I hearing?

>> I know that frequency is used by some trunking systems but this isn't a
>> trunking scanner and these people are clearly just casually talking to
>> each other, usually female - that's what got me paying attention because
>> most of the police frequncies (sorry that's just the way it is here in
>> Central PA) are male.  It seems to disappear quickly as I drive by the
>> source and it is heavy in residential areas.

>> Anybody know?  Thanks!

>> Sent via Deja.com http://www.deja.com/
>> Before you buy.

 
 
 

What is 868mhz - Phone Conversations??

Post by Dave Martinda » Mon, 27 Mar 2000 04:00:00


Quote:>I'm very curious WHY you'd want to discuss something that is illegal
>for most of the users here, including yourself in Georgia.

I'm curious why you think that most of the readers of this newsgroup
live in the USA, where listening to cellphone calls is illegal?

Besides, the frequencies that the guy quoted aren't in the cellular
band, and it hasn't even been established that they *are* cellphones.
Why jump on him so quickly?

        Dave

 
 
 

What is 868mhz - Phone Conversations??

Post by Michael B. Tinsle » Tue, 28 Mar 2000 04:00:00

You're about one big jerk, aren't you Bud?  I bet you're just loaded with
friends and loved ones in the real world, eh?

And to restate... I am NOT accessing the net from Georgia.  I guess you're
just not the net savvy guru you thought you were.

Correct me if I'm wrong.... I think it is perfectly legal to discuss illegal
activities all day long as long as you don't actually participate?  There's
something called... oh let me see.. the 1st Amendment that allows that.  But
I am sure you knew that seeing as how you seem to know everything.

Mike





> >>I'm very curious WHY you'd want to discuss something that is illegal
> >>for most of the users here, including yourself in Georgia.

> >I'm curious why you think that most of the readers of this newsgroup
> >live in the USA, where listening to cellphone calls is illegal?

> Well GEE, Goober, it MIGHT be because I checked where HE was
> accessing the net from, and also the fact that I've been active in
> this newsgroup for over 10 years.

> To reply by email, remove the XYZ.

> Lumber Cartel (tinlc) #2063. Spam this account at your own risk.