Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

Here's the latest: We went up to our site yesterday. We added a lighting 
arrestor to the receive antenna. We grounded the chassis/rail/cabinet as it was 
only grounded via the power cord previously.  Didn't expect this to fix the 
paging problem, it just needed to be done. 

I did find a loose UHF connector on the Wacom. This is a two cavity BP filter 
on the receive side. I don't know if the loose connector was the problem but 
it's much cleaner now. We ran in carrier squelch for about an hour and didn't 
hear much of anything. A dramatic improvement and amazing for our dirty hill. 
Today there have been a couple of pages bust through the P/L but it's 1,000% 
better than it was and it's still pretty quite in carrier squelch. 

Do you think the loose connector and/or grounding could have helped or is this 
some sort of cruel coincidence?
--
Tim
:wq

On Aug 24, 2010, at 3:48 PM, Walter H wrote:

 We also had a problem with a 454 pager.
 Quintron with a 1/4 k amp.
 Only one in the metro area had a spur, but that one traveled as the PA cage 
 changed temperature.
 Got a hold of the paging company, and they turned each one off until we saw 
 the spur go away.
 Final tube had been replaced and not properly neutralized.
 
 WalterH
 
 --- In Repeater-Builder@yahoogroups.com, Tom W2MN w...@... wrote:
 
  We had a pager spur problem with our repeater (no pl). The problem would
  come and go. We determined it happened mostly with time of day (outside
  temperature). Sometime it was just a short 1 second event and sometimes it
  would hold for a bit more (maybe 2 -5 sec). We setup a satellite multimode
  radio (actually dial in the frequency with widest bandwidth setting) and
  monitored the repeater input with a tape recorder and vox. We did this to
  capture the audio so we could listen to characteristics and THE CW CALLSIGN.
  We captured enough of the callsign that we were able to indentify the whole
  call (and freq) from the FCC database. 
  
  With that, we were able to monitor the repeater and the pager for hits. Yes,
  it did hit some times and not others. The reason was, it was caused by an
  unstable spur that drifted up and down the ham band with temperature and the
  amount of pager traffic. It was also hitting other repeaters as it drifted
  but most of the other repeaters had pl. 
  
  There was a chain of pagers using the same freq and callsign and we had to
  figure out which tower it was. We used a beam antenna and chased the spur
  up/down the band until we were able to get a definite direction. The next
  step as to visit the site AREA with an HT and just scan the ham repeater
  input freqs during the likely time of day. Bingo, the spur was loud and
  clear!.
  
  Of course the pager owner was in denial but being a pest for a couple of
  weeks got the problem removed. They claim it was a spur in the final PA that
  had been serviced just at the time the problem started. They replaced the
  PA.
  
  Hope this story helps.
  
  Tom
 
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[DCFluX]

I've seen this before on Wacom BpBr duplexers. Remove the coupling loop from
the cavity and re-solder the connectors. Use 2% silver bearing solder if you
can find it.

On Wed, Aug 25, 2010 at 1:27 PM, Tim Sawyer tisaw...@gmail.com wrote:



 Here's the latest: We went up to our site yesterday. We added a lighting
 arrestor to the receive antenna. We grounded the chassis/rail/cabinet as it
 was only grounded via the power cord previously.  Didn't expect this to fix
 the paging problem, it just needed to be done.

 I did find a loose UHF connector on the Wacom. This is a two cavity BP
 filter on the receive side. I don't know if the loose connector was the
 problem but it's much cleaner now. We ran in carrier squelch for about an
 hour and didn't hear much of anything. A dramatic improvement and amazing
 for our dirty hill. Today there have been a couple of pages bust through the
 P/L but it's 1,000% better than it was and it's still pretty quite in
 carrier squelch.

 Do you think the loose connector and/or grounding could have helped or is
 this some sort of cruel coincidence?
 --
 Tim
 :wq

 On Aug 24, 2010, at 3:48 PM, Walter H wrote:



 We also had a problem with a 454 pager.
 Quintron with a 1/4 k amp.
 Only one in the metro area had a spur, but that one traveled as the PA cage
 changed temperature.
 Got a hold of the paging company, and they turned each one off until we saw
 the spur go away.
 Final tube had been replaced and not properly neutralized.

 WalterH

 --- In Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com,
 Tom W2MN w...@... wrote:
 
  We had a pager spur problem with our repeater (no pl). The problem would
  come and go. We determined it happened mostly with time of day (outside
  temperature). Sometime it was just a short 1 second event and sometimes
 it
  would hold for a bit more (maybe 2 -5 sec). We setup a satellite
 multimode
  radio (actually dial in the frequency with widest bandwidth setting) and
  monitored the repeater input with a tape recorder and vox. We did this to
  capture the audio so we could listen to characteristics and THE CW
 CALLSIGN.
  We captured enough of the callsign that we were able to indentify the
 whole
  call (and freq) from the FCC database.
 
  With that, we were able to monitor the repeater and the pager for hits.
 Yes,
  it did hit some times and not others. The reason was, it was caused by an
  unstable spur that drifted up and down the ham band with temperature and
 the
  amount of pager traffic. It was also hitting other repeaters as it
 drifted
  but most of the other repeaters had pl.
 
  There was a chain of pagers using the same freq and callsign and we had
 to
  figure out which tower it was. We used a beam antenna and chased the spur
  up/down the band until we were able to get a definite direction. The next
  step as to visit the site AREA with an HT and just scan the ham repeater
  input freqs during the likely time of day. Bingo, the spur was loud and
  clear!.
 
  Of course the pager owner was in denial but being a pest for a couple of
  weeks got the problem removed. They claim it was a spur in the final PA
 that
  had been serviced just at the time the problem started. They replaced the
  PA.
 
  Hope this story helps.
 
  Tom
 




 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

This is a couple of pass cavities, not a duplexer. Do the band pass cavities 
have the same problem?

--
Tim
:wq

On Aug 25, 2010, at 1:32 PM, DCFluX wrote:

 I've seen this before on Wacom BpBr duplexers. Remove the coupling loop from 
 the cavity and re-solder the connectors. Use 2% silver bearing solder if you 
 can find it.
 
 
 On Wed, Aug 25, 2010 at 1:27 PM, Tim Sawyer tisaw...@gmail.com wrote:
 
 
 Here's the latest: We went up to our site yesterday. We added a lighting 
 arrestor to the receive antenna. We grounded the chassis/rail/cabinet as it 
 was only grounded via the power cord previously.  Didn't expect this to fix 
 the paging problem, it just needed to be done. 
 
 I did find a loose UHF connector on the Wacom. This is a two cavity BP filter 
 on the receive side. I don't know if the loose connector was the problem but 
 it's much cleaner now. We ran in carrier squelch for about an hour and didn't 
 hear much of anything. A dramatic improvement and amazing for our dirty hill. 
 Today there have been a couple of pages bust through the P/L but it's 1,000% 
 better than it was and it's still pretty quite in carrier squelch. 
 
 Do you think the loose connector and/or grounding could have helped or is 
 this some sort of cruel coincidence?

Re: [Repeater-Builder] Re: Intermod Calculation

[DCFluX]

Possibly. Wiggle the connectors while looking at the cavity on a spectrum
analyzer and if the peaks and dips change significantly that's probably the
problem.

The one I had the solder kinda looked like it was sprayed out of one joint
at the top of the can, and there was a lot of flux around the joint.

On Wed, Aug 25, 2010 at 2:17 PM, Tim Sawyer tisaw...@gmail.com wrote:



 By the way, the Wacom model number is WP-430-2.
 --
 Tim
 :wq

 Begin forwarded message:

 *
 *
 *To: *repeater-buil...@yahoogroups.com
 *Subject: **Re: [Repeater-Builder] Re: Intermod Calculation*

 This is a couple of pass cavities, not a duplexer. Do the band pass
 cavities have the same problem?

 --
 Tim
 :wq

 On Aug 25, 2010, at 1:32 PM, DCFluX wrote:

 I've seen this before on Wacom BpBr duplexers. Remove the coupling loop
 from the cavity and re-solder the connectors. Use 2% silver bearing solder
 if you can find it.

 On Wed, Aug 25, 2010 at 1:27 PM, Tim Sawyer tisaw...@gmail.com wrote:



 Here's the latest: We went up to our site yesterday. We added a lighting
 arrestor to the receive antenna. We grounded the chassis/rail/cabinet as it
 was only grounded via the power cord previously.  Didn't expect this to fix
 the paging problem, it just needed to be done.

 I did find a loose UHF connector on the Wacom. This is a two cavity BP
 filter on the receive side. I don't know if the loose connector was the
 problem but it's much cleaner now. We ran in carrier squelch for about an
 hour and didn't hear much of anything. A dramatic improvement and amazing
 for our dirty hill. Today there have been a couple of pages bust through the
 P/L but it's 1,000% better than it was and it's still pretty quite in
 carrier squelch.

 Do you think the loose connector and/or grounding could have helped or is
 this some sort of cruel coincidence?





 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

Another tidbit about this problem is that it's clean in the mornings. The 
paging transmitter can be going off like crazy and the repeater will be totally 
clean in carrier squelch. As the day progresses it gets worse.  
--
Tim
:wq

On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:

 I agree, if you don't hear anything else in the mix, and it pretty much 
 happens for the full length of the page, it's likely a spur on the paging 
 transmitter, at least that's what I'd be looking at.
 
 Chuck
 WB2EDV
 
 
 
 - Original Message - 
 From: MCH m...@nb.net
 To: Repeater-Builder@yahoogroups.com
 Sent: Friday, August 20, 2010 10:46 PM
 Subject: Re: [Repeater-Builder] Re: Intermod Calculation
 
 
 Could be a spur. Can you hear any other audio with the page? (ever)
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 It seems to pick up most of the page. Occasionally the beginning is
 missing or it will get just the very end. It always seems to drop at the
 same time as the page.
 
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
 
 
 Does the entire page happen, or does it abruptly stop part way through
 some
 of the time? Partial page would indicate to me that another
 transmitter is
 in the mix and dropping before the pager does.
 
 However, I had a situation where there were four paging sites
 scattered in
 the county on the same frequency and one of the transmitters was 
 spurious
 and getting into my receiver. In that case, I always heard the entire
 page,
 but only when that particular transmitter came up.
 
 Chuck
 WB2EDV
 
 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation
 
 It occurs whether or not the repeater transmitter is keyed.
 
 --- In Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@...
 wrote:
 
 
 Before we get into the math, an important question that needs to be
 answered
 is whether or not this mix occurs when your repeater transmitter is
 unkeyed.
 
 
 --- Jeff WN3A
 
 -Original Message-
 From: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
 [mailto:Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Friday, August 20, 2010 6:36 PM
 To: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
 Subject: [Repeater-Builder] Intermod Calculation
 
 
 
 I have paging intermod from 157.740 Mhz. My receiver is on
 144.540 Mhz. I'm 100% sure there is another transmitter
 involved in the mix because sometimes the pager is
 transmitting and I have no interference.
 
 I have an intermod calculator program but it wants all the
 known transmitters and the target receiver. But I need to
 solve for an unknown transmitter. Is there a way to calculate
 the other possible soruce(s)?
 --
 Tim
 :wq
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 --
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
 14:35:00
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 
 
 
 
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10 
 14:35:00
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 

RE: [Repeater-Builder] Re: Intermod Calculation

[Mike Besemer (WM4B)]

I was just wondering.  Sounds like something we had going on here in middle
Georgia.

 

Good luck es 73,

 

Mike

WM4B

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
Sent: Saturday, August 21, 2010 12:43 AM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Intermod Calculation

 

  

I'm in Huntington Beach.

--
Tim
:wq

 

On Aug 20, 2010, at 8:52 PM, Mike Besemer (WM4B) wrote:





  

 

Tim,

 

Where are you located?

 

73,

 

Mike

WM4B

 

  _  

From:  mailto:Repeater-Builder@yahoogroups.com
Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com]
On Behalf Of Tim Sawyer
Sent: Friday, August 20, 2010 11:49 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Intermod Calculation

 

  

No, I never, ever have heard any other audio. But there is time when I don't
hear it at all... as if it takes two signals to occur. 

--
Tim
:wq

On Aug 20, 2010, at 7:46 PM, MCH wrote:

 Could be a spur. Can you hear any other audio with the page? (ever)
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 It seems to pick up most of the page. Occasionally the beginning is 
 missing or it will get just the very end. It always seems to drop at the 
 same time as the page. 
 
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
 
 
 Does the entire page happen, or does it abruptly stop part way through 
 some
 of the time? Partial page would indicate to me that another 
 transmitter is
 in the mix and dropping before the pager does.
 
 However, I had a situation where there were four paging sites 
 scattered in
 the county on the same frequency and one of the transmitters was
spurious
 and getting into my receiver. In that case, I always heard the entire 
 page,
 but only when that particular transmitter came up.
 
 Chuck
 WB2EDV
 
 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation
 
 It occurs whether or not the repeater transmitter is keyed.
 
 --- In Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@... 
 wrote:
 
 
 Before we get into the math, an important question that needs to be
 answered
 is whether or not this mix occurs when your repeater transmitter is
 unkeyed.
 
 
 --- Jeff WN3A
 
 -Original Message-
 From: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com
 [mailto:Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Friday, August 20, 2010 6:36 PM
 To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com
 Subject: [Repeater-Builder] Intermod Calculation
 
 
 
 I have paging intermod from 157.740 Mhz. My receiver is on
 144.540 Mhz. I'm 100% sure there is another transmitter
 involved in the mix because sometimes the pager is
 transmitting and I have no interference.
 
 I have an intermod calculator program but it wants all the
 known transmitters and the target receiver. But I need to
 solve for an unknown transmitter. Is there a way to calculate
 the other possible soruce(s)?
 --
 Tim
 :wq
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 --
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com http://www.avg.com/ 
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
 14:35:00
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 

 

 

RE: [Repeater-Builder] Re: Intermod Calculation

[Mike Besemer (WM4B)]

What about hot vs. cold days and sunny vs. cloudy?

 

We'd see our problem on hot days pretty much all the time.  Cool and cloudy
(or cold) days were quiet.  Cool days with full sun usually caused the
problem to occur.  You could almost set your watch by it.

 

73,

 

Mike

WM4B

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
Sent: Saturday, August 21, 2010 9:37 AM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Intermod Calculation

 

  

Another tidbit about this problem is that it's clean in the mornings. The
paging transmitter can be going off like crazy and the repeater will be
totally clean in carrier squelch. As the day progresses it gets worse. 
--
Tim
:wq

On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:

 I agree, if you don't hear anything else in the mix, and it pretty much 
 happens for the full length of the page, it's likely a spur on the paging 
 transmitter, at least that's what I'd be looking at.
 
 Chuck
 WB2EDV
 
 
 
 - Original Message - 
 From: MCH m...@nb.net mailto:mch%40nb.net 
 To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com 
 Sent: Friday, August 20, 2010 10:46 PM
 Subject: Re: [Repeater-Builder] Re: Intermod Calculation
 
 
 Could be a spur. Can you hear any other audio with the page? (ever)
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 It seems to pick up most of the page. Occasionally the beginning is
 missing or it will get just the very end. It always seems to drop at the
 same time as the page.
 
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
 
 
 Does the entire page happen, or does it abruptly stop part way through
 some
 of the time? Partial page would indicate to me that another
 transmitter is
 in the mix and dropping before the pager does.
 
 However, I had a situation where there were four paging sites
 scattered in
 the county on the same frequency and one of the transmitters was 
 spurious
 and getting into my receiver. In that case, I always heard the entire
 page,
 but only when that particular transmitter came up.
 
 Chuck
 WB2EDV
 
 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation
 
 It occurs whether or not the repeater transmitter is keyed.
 
 --- In Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@...
 wrote:
 
 
 Before we get into the math, an important question that needs to be
 answered
 is whether or not this mix occurs when your repeater transmitter is
 unkeyed.
 
 
 --- Jeff WN3A
 
 -Original Message-
 From: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
 [mailto:Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Friday, August 20, 2010 6:36 PM
 To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
 Subject: [Repeater-Builder] Intermod Calculation
 
 
 
 I have paging intermod from 157.740 Mhz. My receiver is on
 144.540 Mhz. I'm 100% sure there is another transmitter
 involved in the mix because sometimes the pager is
 transmitting and I have no interference.
 
 I have an intermod calculator program but it wants all the
 known transmitters and the target receiver. But I need to
 solve for an unknown transmitter. Is there a way to calculate
 the other possible soruce(s)?
 --
 Tim
 :wq
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 --
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date:
08/20/10
 14:35:00
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 
 --
 
 
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10 
 14:35:00
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[MCH]

Again, just like a spur.

Does it have a 'grungy' sound to it when you hear it on your input?

Might also be worth putting the Spectrum Analyzer on your input to see 
if you can see it drifting through the frequency - or drifting onto it.

Joe M.

Tim Sawyer wrote:
 Another tidbit about this problem is that it's clean in the mornings. The 
 paging transmitter can be going off like crazy and the repeater will be 
 totally clean in carrier squelch. As the day progresses it gets worse.  
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:
 
 I agree, if you don't hear anything else in the mix, and it pretty much 
 happens for the full length of the page, it's likely a spur on the paging 
 transmitter, at least that's what I'd be looking at.

 Chuck
 WB2EDV



 - Original Message - 
 From: MCH m...@nb.net
 To: Repeater-Builder@yahoogroups.com
 Sent: Friday, August 20, 2010 10:46 PM
 Subject: Re: [Repeater-Builder] Re: Intermod Calculation


 Could be a spur. Can you hear any other audio with the page? (ever)

 Joe M.

 Tim Sawyer wrote:

 It seems to pick up most of the page. Occasionally the beginning is
 missing or it will get just the very end. It always seems to drop at the
 same time as the page.

 --
 Tim
 :wq

 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:


 Does the entire page happen, or does it abruptly stop part way through
 some
 of the time? Partial page would indicate to me that another
 transmitter is
 in the mix and dropping before the pager does.

 However, I had a situation where there were four paging sites
 scattered in
 the county on the same frequency and one of the transmitters was 
 spurious
 and getting into my receiver. In that case, I always heard the entire
 page,
 but only when that particular transmitter came up.

 Chuck
 WB2EDV

 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation

 It occurs whether or not the repeater transmitter is keyed.

 --- In Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@...
 wrote:

 Before we get into the math, an important question that needs to be
 answered
 is whether or not this mix occurs when your repeater transmitter is
 unkeyed.


 --- Jeff WN3A

 -Original Message-
 From: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
 [mailto:Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Friday, August 20, 2010 6:36 PM
 To: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
 Subject: [Repeater-Builder] Intermod Calculation



 I have paging intermod from 157.740 Mhz. My receiver is on
 144.540 Mhz. I'm 100% sure there is another transmitter
 involved in the mix because sometimes the pager is
 transmitting and I have no interference.

 I have an intermod calculator program but it wants all the
 known transmitters and the target receiver. But I need to
 solve for an unknown transmitter. Is there a way to calculate
 the other possible soruce(s)?
 --
 Tim
 :wq








 



 Yahoo! Groups Links



 --

 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
 14:35:00





 



 Yahoo! Groups Links




 



 No virus found in this incoming message.
 Checked by AVG - www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10 
 14:35:00



 



 Yahoo! Groups Links



 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 
 
 
 Internal Virus Database is out of date.
 Checked by AVG - www.avg.com 
 Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: 03/14/10 
 03:33:00
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

I'm not sure what you mean by grungy.  What are you getting at?
--
Tim
:wq

On Aug 21, 2010, at 6:59 AM, MCH wrote:

 Does it have a 'grungy' sound to it when you hear it on your input?

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

I'm looking at the pager freq with the SA. The dev looks wide to me. I see 
about 15 Khz peak to peak. Is that normal?

Also I see much bigger spikes. 
 
--
Tim
:wq

On Aug 21, 2010, at 6:59 AM, MCH wrote:

 Again, just like a spur.
 
 Does it have a 'grungy' sound to it when you hear it on your input?
 
 Might also be worth putting the Spectrum Analyzer on your input to see 
 if you can see it drifting through the frequency - or drifting onto it.
 
 Joe M.
 
 Tim Sawyer wrote:
  Another tidbit about this problem is that it's clean in the mornings. The 
  paging transmitter can be going off like crazy and the repeater will be 
  totally clean in carrier squelch. As the day progresses it gets worse. 
  --
  Tim
  :wq
  
  On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:
  
  I agree, if you don't hear anything else in the mix, and it pretty much 
  happens for the full length of the page, it's likely a spur on the paging 
  transmitter, at least that's what I'd be looking at.
 
  Chuck
  WB2EDV
 
 
 
  - Original Message - 
  From: MCH m...@nb.net
  To: Repeater-Builder@yahoogroups.com
  Sent: Friday, August 20, 2010 10:46 PM
  Subject: Re: [Repeater-Builder] Re: Intermod Calculation
 
 
  Could be a spur. Can you hear any other audio with the page? (ever)
 
  Joe M.
 
  Tim Sawyer wrote:
 
  It seems to pick up most of the page. Occasionally the beginning is
  missing or it will get just the very end. It always seems to drop at the
  same time as the page.
 
  --
  Tim
  :wq
 
  On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
 
  Does the entire page happen, or does it abruptly stop part way through
  some
  of the time? Partial page would indicate to me that another
  transmitter is
  in the mix and dropping before the pager does.
 
  However, I had a situation where there were four paging sites
  scattered in
  the county on the same frequency and one of the transmitters was 
  spurious
  and getting into my receiver. In that case, I always heard the entire
  page,
  but only when that particular transmitter came up.
 
  Chuck
  WB2EDV
 
  - Original Message -
  From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
  To: Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com
  Sent: Friday, August 20, 2010 7:27 PM
  Subject: [Repeater-Builder] Re: Intermod Calculation
 
  It occurs whether or not the repeater transmitter is keyed.
 
  --- In Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@...
  wrote:
 
  Before we get into the math, an important question that needs to be
  answered
  is whether or not this mix occurs when your repeater transmitter is
  unkeyed.
 
 
  --- Jeff WN3A
 
  -Original Message-
  From: Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com
  [mailto:Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
  Sent: Friday, August 20, 2010 6:36 PM
  To: Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com
  Subject: [Repeater-Builder] Intermod Calculation
 
 
 
  I have paging intermod from 157.740 Mhz. My receiver is on
  144.540 Mhz. I'm 100% sure there is another transmitter
  involved in the mix because sometimes the pager is
  transmitting and I have no interference.
 
  I have an intermod calculator program but it wants all the
  known transmitters and the target receiver. But I need to
  solve for an unknown transmitter. Is there a way to calculate
  the other possible soruce(s)?
  --
  Tim
  :wq
 
 
 
 
 
 
 
 
  
 
 
 
  Yahoo! Groups Links
 
 
 
  --
 
  No virus found in this incoming message.
  Checked by AVG - www.avg.com http://www.avg.com
  Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
  14:35:00
 
 
 
 
 
  
 
 
 
  Yahoo! Groups Links
 
 
 
 
  --
 
 
 
  No virus found in this incoming message.
  Checked by AVG - www.avg.com
  Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10 
  14:35:00
 
 
 
  
 
 
 
  Yahoo! Groups Links
 
 
 
  
  
  
  
  
  
  
  Yahoo! Groups Links
  
  
  
  
  --
  
  
  Internal Virus Database is out of date.
  Checked by AVG - www.avg.com 
  Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: 03/14/10 
  03:33:00
  
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Matthew Kaufman]

Tim Sawyer wrote:


 It seems to pick up most of the page. Occasionally the beginning is 
 missing or it will get just the very end. It always seems to drop at 
 the same time as the page. 

Does the repeater run CTCSS on the input? If so, is the behavior the 
same if CTCSS is off? (CTCSS might clip the signal off at one end or the 
other, even though the receiver is hearing the whole thing)

Can you hear the signal using a completely different receiver on the 
same frequency at the site? (Preferably one that uses a different first 
IF frequency, tests to see if it is getting into the IF or if the 
intermod product is an image rather than the actual receive frequency)

Does it happen out of the blue with the repeater inactive, or only 
when the repeater has been in-use? (Tests to see if the repeater 
transmitter is part of the mix)

Does the paging sound exactly the same, or might you be hearing a link 
transmitter? (many are on 72 MHz, exactly half your input frequency)


Matthew Kaufman






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Re: [Repeater-Builder] Re: Intermod Calculation

[MCH]

Many times (but not all), there will be a grungy sound with the spur. 
Think of a very loud 60 cycle hum.

And 15 kHz is higher than normal. I think the typical shift is 5 kHz 
(+/- 2.5 kHz) if we are talking about digital paging. Analog might be 15 
kHz, as the bandwidth limit would be 16 kHz.

Joe M.

Tim Sawyer wrote:
 
 
 I'm not sure what you mean by grungy.  What are you getting at?
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 6:59 AM, MCH wrote:
 
 Does it have a 'grungy' sound to it when you hear it on your input?
 
 
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

Yes the repeater has CTCSS but I turn it off for testing. When on the CTCSS 
will false but that's not what I'm talking about when I say that the repeater 
sometimes keys up after the beginning of the page.  

I'm going to take another repeater which has a different 1st IF up and test 
with just as you suggest. It's a VXR-5000 with a 1st IF of 21.6 Mhz and a 2nd 
IF of 455. The current repeater (a Micor) has a 11.7 IF and is single 
conversion.

Yes, it happens out of the blue. I'm confident that the repeater TX is not part 
of the mix. 

The paging does sound a bit different. I've been think that's due to the wide 
dev (15 Khz plus) and that different receivers would hear that differently.

I talked to the tech and he told me the system has a satellite feed. He also 
told me the same feed goes to their transmitter on 929.0375 Mhz. Basically, 
there is one controller for both the 929.0375 and the 157.74 transmitters. They 
also have two other transmitters on 929.6375 and 931.6625.
--
Tim
:wq

On Aug 21, 2010, at 9:18 AM, Matthew Kaufman wrote:

 Tim Sawyer wrote:
 
 
 It seems to pick up most of the page. Occasionally the beginning is 
 missing or it will get just the very end. It always seems to drop at 
 the same time as the page. 
 
 Does the repeater run CTCSS on the input? If so, is the behavior the 
 same if CTCSS is off? (CTCSS might clip the signal off at one end or the 
 other, even though the receiver is hearing the whole thing)
 
 Can you hear the signal using a completely different receiver on the 
 same frequency at the site? (Preferably one that uses a different first 
 IF frequency, tests to see if it is getting into the IF or if the 
 intermod product is an image rather than the actual receive frequency)
 
 Does it happen out of the blue with the repeater inactive, or only 
 when the repeater has been in-use? (Tests to see if the repeater 
 transmitter is part of the mix)
 
 Does the paging sound exactly the same, or might you be hearing a link 
 transmitter? (many are on 72 MHz, exactly half your input frequency)
 
 
 Matthew Kaufman
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

I haven't noticed a hum. There's more of a scream on it. 

It's POCSAG. Is that analog? 

The dev is basically 15 Khz but there is, what I going to call splatter that is 
like 30 Khz. 
--
Tim
:wq

On Aug 21, 2010, at 10:14 AM, MCH wrote:

 Many times (but not all), there will be a grungy sound with the spur. 
 Think of a very loud 60 cycle hum.
 
 And 15 kHz is higher than normal. I think the typical shift is 5 kHz 
 (+/- 2.5 kHz) if we are talking about digital paging. Analog might be 15 
 kHz, as the bandwidth limit would be 16 kHz.
 
 Joe M.
 
 Tim Sawyer wrote:
  
  
  I'm not sure what you mean by grungy. What are you getting at?
  --
  Tim
  :wq
  
  On Aug 21, 2010, at 6:59 AM, MCH wrote:
  
  Does it have a 'grungy' sound to it when you hear it on your input?
  
  
  
  
 

RE: [Repeater-Builder] Re: Intermod Calculation

[Jeff DePolo]

The deviation is 15 kHz, or you're seeing 15 kHz of bandwidth on the
spectrum analyzer?  The latter would be normal, the former wouldn't be. 

 -Original Message-
 From: Repeater-Builder@yahoogroups.com 
 [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Saturday, August 21, 2010 1:33 PM
 To: Repeater-Builder@yahoogroups.com
 Subject: Re: [Repeater-Builder] Re: Intermod Calculation
 
   
 
 I haven't noticed a hum. There's more of a scream on it. 
 
 It's POCSAG. Is that analog? 
 
 The dev is basically 15 Khz but there is, what I going to 
 call splatter that is like 30 Khz. 
 
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 10:14 AM, MCH wrote:
 
 
 
 
   Many times (but not all), there will be a grungy sound 
 with the spur. 
   Think of a very loud 60 cycle hum.
   
   And 15 kHz is higher than normal. I think the typical 
 shift is 5 kHz 
   (+/- 2.5 kHz) if we are talking about digital paging. 
 Analog might be 15 
   kHz, as the bandwidth limit would be 16 kHz.
   
   Joe M.
   
   Tim Sawyer wrote:


I'm not sure what you mean by grungy. What are you getting at?
--
Tim
:wq

On Aug 21, 2010, at 6:59 AM, MCH wrote:

Does it have a 'grungy' sound to it when you hear it 
 on your input?




   
 
 
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[men...@pa.net]

Tim,

Digital paging (mostly POCSAG coding these days) is FSK and will  
easily occupy 15KHz of bandwidth.

On a Service Monitor deviation screen you will see a square wave  
pattern that looks like it is overdeviated unless you are very close  
to the transmitter in question.  Read on and you will see why a  
deviation measurement is of little use.

On a Spectrum Analyser you will see a single spike that jumps back and  
forth between a freq higher than the channel center and a freq lower  
than the channel center.  The typical digital paging transmitter  
settings are +4KHz above the assigned freq and - 4KHz below the  
assigned freq.  If the system uses multiple transmitters the + and -  
settings may be asymmetrical to allow for slight offsets between  
transmitters.  As demodulated at the paging receiver the signal is a  
1200 baud pattern of square waves.

Newer systems such as FLEX may have two levels of + and -  with  
settings of say +4K +2K -2K and -4K.

If the problem is the digital paging transmitter you need to determine  
how close the transmitter is to your installation.  Paging receivers  
represent a compromised antenna system and most paging transmitters  
compensate for the shortcomings of the receiver by sending at very  
high power levels.  If the paging transmitter is close to you, it  
might be meeting spec but the low level grundge could be causing you  
problems.

Milt
N3LTQ




Quoting Tim Sawyer tisaw...@gmail.com:

 I'm looking at the pager freq with the SA. The dev looks wide to me.  
 I see about 15 Khz peak to peak. Is that normal?

 Also I see much bigger spikes.

 --
 Tim
 :wq

 On Aug 21, 2010, at 6:59 AM, MCH wrote:

 Again, just like a spur.

 Does it have a 'grungy' sound to it when you hear it on your input?

 Might also be worth putting the Spectrum Analyzer on your input to see
 if you can see it drifting through the frequency - or drifting onto it.

 Joe M.

 Tim Sawyer wrote:
  Another tidbit about this problem is that it's clean in the  
 mornings. The paging transmitter can be going off like crazy and  
 the repeater will be totally clean in carrier squelch. As the day  
 progresses it gets worse.
  --
  Tim
  :wq
 
  On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:
 
  I agree, if you don't hear anything else in the mix, and it pretty much
  happens for the full length of the page, it's likely a spur on the paging
  transmitter, at least that's what I'd be looking at.
 
  Chuck
  WB2EDV
 
 
 
  - Original Message -
  From: MCH m...@nb.net
  To: Repeater-Builder@yahoogroups.com
  Sent: Friday, August 20, 2010 10:46 PM
  Subject: Re: [Repeater-Builder] Re: Intermod Calculation
 
 
  Could be a spur. Can you hear any other audio with the page? (ever)
 
  Joe M.
 
  Tim Sawyer wrote:
 
  It seems to pick up most of the page. Occasionally the beginning is
  missing or it will get just the very end. It always seems to  
 drop at the
  same time as the page.
 
  --
  Tim
  :wq
 
  On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
 
  Does the entire page happen, or does it abruptly stop part way through
  some
  of the time? Partial page would indicate to me that another
  transmitter is
  in the mix and dropping before the pager does.
 
  However, I had a situation where there were four paging sites
  scattered in
  the county on the same frequency and one of the transmitters was
  spurious
  and getting into my receiver. In that case, I always heard the entire
  page,
  but only when that particular transmitter came up.
 
  Chuck
  WB2EDV
 
  - Original Message -
  From: Tim - WD6AWP tisaw...@gmail.com  
 mailto:tisawyer%40gmail.com
  To: Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com
  Sent: Friday, August 20, 2010 7:27 PM
  Subject: [Repeater-Builder] Re: Intermod Calculation
 
  It occurs whether or not the repeater transmitter is keyed.
 
  --- In Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@...
  wrote:
 
  Before we get into the math, an important question that needs to be
  answered
  is whether or not this mix occurs when your repeater transmitter is
  unkeyed.
 
 
  --- Jeff WN3A
 
  -Original Message-
  From: Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com
  [mailto:Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
  Sent: Friday, August 20, 2010 6:36 PM
  To: Repeater-Builder@yahoogroups.com
  mailto:Repeater-Builder%40yahoogroups.com
  Subject: [Repeater-Builder] Intermod Calculation
 
 
 
  I have paging intermod from 157.740 Mhz. My receiver is on
  144.540 Mhz. I'm 100% sure there is another transmitter
  involved in the mix because sometimes the pager is
  transmitting and I have no interference.
 
  I have an intermod calculator program but it wants all the
  known transmitters and the target receiver. But I need to
  solve for an unknown transmitter. Is there a way

Re: [Repeater-Builder] Re: Intermod Calculation

[MCH]

Before you said 15 kHz P-P (IOW bandwidth). Now you're saying 15 kHz 
deviation. 15 kHz deviation would be way too high.

Joe M.

Tim Sawyer wrote:
 
 
 I haven't noticed a hum. There's more of a scream on it. 
 
 It's POCSAG. Is that analog? 
 
 The dev is basically 15 Khz but there is, what I going to call splatter 
 that is like 30 Khz. 
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 10:14 AM, MCH wrote:
 
  

 Many times (but not all), there will be a grungy sound with the spur.
 Think of a very loud 60 cycle hum.

 And 15 kHz is higher than normal. I think the typical shift is 5 kHz
 (+/- 2.5 kHz) if we are talking about digital paging. Analog might be 15
 kHz, as the bandwidth limit would be 16 kHz.

 Joe M.

 Tim Sawyer wrote:
 
 
  I'm not sure what you mean by grungy. What are you getting at?
  --
  Tim
  :wq
 
  On Aug 21, 2010, at 6:59 AM, MCH wrote:
 
  Does it have a 'grungy' sound to it when you hear it on your input?
 
 
 
 

 
 
 
 
 
 
 
 
 
 Internal Virus Database is out of date.
 Checked by AVG - www.avg.com 
 Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: 03/14/10 
 03:33:00
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

The deviation is 15 Khz.
--
Tim
:wq

On Aug 21, 2010, at 10:52 AM, Jeff DePolo wrote:

 
 The deviation is 15 kHz, or you're seeing 15 kHz of bandwidth on the
 spectrum analyzer? The latter would be normal, the former wouldn't be. 
 
  -Original Message-
  From: Repeater-Builder@yahoogroups.com 
  [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
  Sent: Saturday, August 21, 2010 1:33 PM
  To: Repeater-Builder@yahoogroups.com
  Subject: Re: [Repeater-Builder] Re: Intermod Calculation
  
  
  
  I haven't noticed a hum. There's more of a scream on it. 
  
  It's POCSAG. Is that analog? 
  
  The dev is basically 15 Khz but there is, what I going to 
  call splatter that is like 30 Khz. 
  
  --
  Tim
  :wq
  
  On Aug 21, 2010, at 10:14 AM, MCH wrote:
  
  
  
  
  Many times (but not all), there will be a grungy sound 
  with the spur. 
  Think of a very loud 60 cycle hum.
  
  And 15 kHz is higher than normal. I think the typical 
  shift is 5 kHz 
  (+/- 2.5 kHz) if we are talking about digital paging. 
  Analog might be 15 
  kHz, as the bandwidth limit would be 16 kHz.
  
  Joe M.
  
  Tim Sawyer wrote:
   
   
   I'm not sure what you mean by grungy. What are you getting at?
   --
   Tim
   :wq
   
   On Aug 21, 2010, at 6:59 AM, MCH wrote:
   
   Does it have a 'grungy' sound to it when you hear it 
  on your input?
   
   
   
   
  
  
  
  
  
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

My service monitor (HP 8924C) has both a deviation meter and an oscilloscope to 
display the demodulated audio. Both the numbers on the dev meter and the peak 
to peak on the scope read about 15 Khz.  

I see another paging system (152.84) that shows the same 15 Khz dev, and a 
bunch of other ones that show 5 Khz dev.

--
Tim
:wq

On Aug 21, 2010, at 12:18 PM, MCH wrote:

 Before you said 15 kHz P-P (IOW bandwidth). Now you're saying 15 kHz 
 deviation. 15 kHz deviation would be way too high.
 
 Joe M.
 
 Tim Sawyer wrote:
  
  
  I haven't noticed a hum. There's more of a scream on it. 
  
  It's POCSAG. Is that analog? 
  
  The dev is basically 15 Khz but there is, what I going to call splatter 
  that is like 30 Khz. 
  --
  Tim
  :wq
  
  On Aug 21, 2010, at 10:14 AM, MCH wrote:
  
  
 
  Many times (but not all), there will be a grungy sound with the spur.
  Think of a very loud 60 cycle hum.
 
  And 15 kHz is higher than normal. I think the typical shift is 5 kHz
  (+/- 2.5 kHz) if we are talking about digital paging. Analog might be 15
  kHz, as the bandwidth limit would be 16 kHz.
 
  Joe M.
 
  Tim Sawyer wrote:
  
  
   I'm not sure what you mean by grungy. What are you getting at?
   --
   Tim
   :wq
  
   On Aug 21, 2010, at 6:59 AM, MCH wrote:
  
   Does it have a 'grungy' sound to it when you hear it on your input?
  
  
  
  
 
  
  
  
  
  
  
  --
  
  
  Internal Virus Database is out of date.
  Checked by AVG - www.avg.com 
  Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: 03/14/10 
  03:33:00
  
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

I have noticed the carrier appears to jump between +4 and -4 Khz of center. 

The transmitter is about 75 yards from me. It's running 225 watts according to 
the tech.

The interference is pretty strong. It competes with my base station on low 
power. I'm 25 miles from the repeater.  
--
Tim
:wq

On Aug 21, 2010, at 11:25 AM, men...@pa.net wrote:

 Tim,
 
 Digital paging (mostly POCSAG coding these days) is FSK and will 
 easily occupy 15KHz of bandwidth.
 
 On a Service Monitor deviation screen you will see a square wave 
 pattern that looks like it is overdeviated unless you are very close 
 to the transmitter in question. Read on and you will see why a 
 deviation measurement is of little use.
 
 On a Spectrum Analyser you will see a single spike that jumps back and 
 forth between a freq higher than the channel center and a freq lower 
 than the channel center. The typical digital paging transmitter 
 settings are +4KHz above the assigned freq and - 4KHz below the 
 assigned freq. If the system uses multiple transmitters the + and - 
 settings may be asymmetrical to allow for slight offsets between 
 transmitters. As demodulated at the paging receiver the signal is a 
 1200 baud pattern of square waves.
 
 Newer systems such as FLEX may have two levels of + and - with 
 settings of say +4K +2K -2K and -4K.
 
 If the problem is the digital paging transmitter you need to determine 
 how close the transmitter is to your installation. Paging receivers 
 represent a compromised antenna system and most paging transmitters 
 compensate for the shortcomings of the receiver by sending at very 
 high power levels. If the paging transmitter is close to you, it 
 might be meeting spec but the low level grundge could be causing you 
 problems.
 
 Milt
 N3LTQ
 
 Quoting Tim Sawyer tisaw...@gmail.com:
 
  I'm looking at the pager freq with the SA. The dev looks wide to me. 
  I see about 15 Khz peak to peak. Is that normal?
 
  Also I see much bigger spikes.
 
  --
  Tim
  :wq
 
  On Aug 21, 2010, at 6:59 AM, MCH wrote:
 
  Again, just like a spur.
 
  Does it have a 'grungy' sound to it when you hear it on your input?
 
  Might also be worth putting the Spectrum Analyzer on your input to see
  if you can see it drifting through the frequency - or drifting onto it.
 
  Joe M.
 
  Tim Sawyer wrote:
   Another tidbit about this problem is that it's clean in the 
  mornings. The paging transmitter can be going off like crazy and 
  the repeater will be totally clean in carrier squelch. As the day 
  progresses it gets worse.
   --
   Tim
   :wq
  
   On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:
  
   I agree, if you don't hear anything else in the mix, and it pretty much
   happens for the full length of the page, it's likely a spur on the 
   paging
   transmitter, at least that's what I'd be looking at.
  
   Chuck
   WB2EDV
  
  
  
   - Original Message -
   From: MCH m...@nb.net
   To: Repeater-Builder@yahoogroups.com
   Sent: Friday, August 20, 2010 10:46 PM
   Subject: Re: [Repeater-Builder] Re: Intermod Calculation
  
  
   Could be a spur. Can you hear any other audio with the page? (ever)
  
   Joe M.
  
   Tim Sawyer wrote:
  
   It seems to pick up most of the page. Occasionally the beginning is
   missing or it will get just the very end. It always seems to 
  drop at the
   same time as the page.
  
   --
   Tim
   :wq
  
   On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
  
  
   Does the entire page happen, or does it abruptly stop part way 
   through
   some
   of the time? Partial page would indicate to me that another
   transmitter is
   in the mix and dropping before the pager does.
  
   However, I had a situation where there were four paging sites
   scattered in
   the county on the same frequency and one of the transmitters was
   spurious
   and getting into my receiver. In that case, I always heard the entire
   page,
   but only when that particular transmitter came up.
  
   Chuck
   WB2EDV
  
   - Original Message -
   From: Tim - WD6AWP tisaw...@gmail.com 
  mailto:tisawyer%40gmail.com
   To: Repeater-Builder@yahoogroups.com
   mailto:Repeater-Builder%40yahoogroups.com
   Sent: Friday, August 20, 2010 7:27 PM
   Subject: [Repeater-Builder] Re: Intermod Calculation
  
   It occurs whether or not the repeater transmitter is keyed.
  
   --- In Repeater-Builder@yahoogroups.com
   mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@...
   wrote:
  
   Before we get into the math, an important question that needs to be
   answered
   is whether or not this mix occurs when your repeater transmitter is
   unkeyed.
  
  
   --- Jeff WN3A
  
   -Original Message-
   From: Repeater-Builder@yahoogroups.com
   mailto:Repeater-Builder%40yahoogroups.com
   [mailto:Repeater-Builder@yahoogroups.com
   mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
   Sent: Friday, August 20, 2010 6:36 PM
   To: Repeater-Builder@yahoogroups.com
   mailto:Repeater

Re: [Repeater-Builder] Re: Intermod Calculation

[MCH]

There is something wrong with your SM, then, as it should not show a 
deviation of 15 kHz on a signal that is 15 kHz P-P unless it's only 
deviating in one direction from the carrier.

The +/- 4 kHz sounds about right. But, it should be centered around the 
carrier frequency of 157.740 (Or, on 157.736 and 157.744). It would also 
equate to a P-P of about 8 kHz as there is nothing but a shifted carrier 
involved.

Regardless, I suspect none of this relates to your problem.

If it's only 75 yards from you, I bet it's a very weak spur. It's likely 
down far enough that it's legal, too. If that is the case, the only 
thing that will solve it is putting a filter on its TX to notch your 
repeater RX frequency (good luck getting that to happen if it's not on 
the same site - and often if it is on the same site).

Joe M.

Tim Sawyer wrote:
 
 
 My service monitor (HP 8924C) has both a deviation meter and an 
 oscilloscope to display the demodulated audio. Both the numbers on the 
 dev meter and the peak to peak on the scope read about 15 Khz.  
 
 I see another paging system (152.84) that shows the same 15 Khz dev, and 
 a bunch of other ones that show 5 Khz dev.
 
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 12:18 PM, MCH wrote:
 
  

 Before you said 15 kHz P-P (IOW bandwidth). Now you're saying 15 kHz
 deviation. 15 kHz deviation would be way too high.

 Joe M.

 Tim Sawyer wrote:
 
 
  I haven't noticed a hum. There's more of a scream on it.
 
  It's POCSAG. Is that analog?
 
  The dev is basically 15 Khz but there is, what I going to call splatter
  that is like 30 Khz.
  --
  Tim
  :wq
 
  On Aug 21, 2010, at 10:14 AM, MCH wrote:
 
 
 
  Many times (but not all), there will be a grungy sound with the spur.
  Think of a very loud 60 cycle hum.
 
  And 15 kHz is higher than normal. I think the typical shift is 5 kHz
  (+/- 2.5 kHz) if we are talking about digital paging. Analog might 
 be 15
  kHz, as the bandwidth limit would be 16 kHz.
 
  Joe M.
 
  Tim Sawyer wrote:
  
  
   I'm not sure what you mean by grungy. What are you getting at?
   --
   Tim
   :wq
  
   On Aug 21, 2010, at 6:59 AM, MCH wrote:
  
   Does it have a 'grungy' sound to it when you hear it on your input?
  
  
  
  
 
 
 
 
 
 
 
  --
 
 
  Internal Virus Database is out of date.
  Checked by AVG - www.avg.com http://www.avg.com
  Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: 
 03/14/10 03:33:00
 

 
 
 
 






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Re: [Repeater-Builder] Re: Intermod Calculation

[MCH]

You might be able to get the paging company to swap out the transmitter 
or at least the PA. That may solve the problem, too. Or, if you can show 
them the interference, and they are sympathetic, they may fix it.

One bright side: Paging companies are going the way of the dinosaur, so 
it may not be on the air much longer. There used to be a couple dozen 
paging companies in my area. Now there are 5 or 6 left - mostly on UHF/900.

Joe M.

Tim Sawyer wrote:
 
 
 I have noticed the carrier appears to jump between +4 and -4 Khz of center. 
 
 The transmitter is about 75 yards from me. It's running 225 watts 
 according to the tech.
 
 The interference is pretty strong. It competes with my base station on 
 low power. I'm 25 miles from the repeater.  
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 11:25 AM, men...@pa.net mailto:men...@pa.net wrote:
 
  

 Tim,

 Digital paging (mostly POCSAG coding these days) is FSK and will
 easily occupy 15KHz of bandwidth.

 On a Service Monitor deviation screen you will see a square wave
 pattern that looks like it is overdeviated unless you are very close
 to the transmitter in question. Read on and you will see why a
 deviation measurement is of little use.

 On a Spectrum Analyser you will see a single spike that jumps back and
 forth between a freq higher than the channel center and a freq lower
 than the channel center. The typical digital paging transmitter
 settings are +4KHz above the assigned freq and - 4KHz below the
 assigned freq. If the system uses multiple transmitters the + and -
 settings may be asymmetrical to allow for slight offsets between
 transmitters. As demodulated at the paging receiver the signal is a
 1200 baud pattern of square waves.

 Newer systems such as FLEX may have two levels of + and - with
 settings of say +4K +2K -2K and -4K.

 If the problem is the digital paging transmitter you need to determine
 how close the transmitter is to your installation. Paging receivers
 represent a compromised antenna system and most paging transmitters
 compensate for the shortcomings of the receiver by sending at very
 high power levels. If the paging transmitter is close to you, it
 might be meeting spec but the low level grundge could be causing you
 problems.

 Milt
 N3LTQ

 Quoting Tim Sawyer tisaw...@gmail.com mailto:tisawyer%40gmail.com:

  I'm looking at the pager freq with the SA. The dev looks wide to me.
  I see about 15 Khz peak to peak. Is that normal?
 
  Also I see much bigger spikes.
 
  --
  Tim
  :wq
 
  On Aug 21, 2010, at 6:59 AM, MCH wrote:
 
  Again, just like a spur.
 
  Does it have a 'grungy' sound to it when you hear it on your input?
 
  Might also be worth putting the Spectrum Analyzer on your input to see
  if you can see it drifting through the frequency - or drifting onto it.
 
  Joe M.
 
  Tim Sawyer wrote:
   Another tidbit about this problem is that it's clean in the
  mornings. The paging transmitter can be going off like crazy and
  the repeater will be totally clean in carrier squelch. As the day
  progresses it gets worse.
   --
   Tim
   :wq
  
   On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:
  
   I agree, if you don't hear anything else in the mix, and it 
 pretty much
   happens for the full length of the page, it's likely a spur on 
 the paging
   transmitter, at least that's what I'd be looking at.
  
   Chuck
   WB2EDV
  
  
  
   - Original Message -
   From: MCH m...@nb.net mailto:mch%40nb.net
   To: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
   Sent: Friday, August 20, 2010 10:46 PM
   Subject: Re: [Repeater-Builder] Re: Intermod Calculation
  
  
   Could be a spur. Can you hear any other audio with the page? (ever)
  
   Joe M.
  
   Tim Sawyer wrote:
  
   It seems to pick up most of the page. Occasionally the 
 beginning is
   missing or it will get just the very end. It always seems to
  drop at the
   same time as the page.
  
   --
   Tim
   :wq
  
   On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
  
  
   Does the entire page happen, or does it abruptly stop part 
 way through
   some
   of the time? Partial page would indicate to me that another
   transmitter is
   in the mix and dropping before the pager does.
  
   However, I had a situation where there were four paging sites
   scattered in
   the county on the same frequency and one of the transmitters was
   spurious
   and getting into my receiver. In that case, I always heard 
 the entire
   page,
   but only when that particular transmitter came up.
  
   Chuck
   WB2EDV
  
   - Original Message -
   From: Tim - WD6AWP tisaw...@gmail.com 
 mailto:tisawyer%40gmail.com
  mailto:tisawyer%40gmail.com
   To: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
   mailto:Repeater-Builder%40yahoogroups.com
   Sent: Friday, August 20, 2010 7:27 PM
   Subject: [Repeater-Builder] Re: Intermod Calculation
  
   It occurs whether or not the repeater transmitter is keyed

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

The meter reads P-P just like the scope. I generally set dev with the meter and 
confirm it on the scope. But your right, this really doesn't matter. I was just 
making sure they didn't have the dev out of wack and from what I gather here 
they don't.

We're going up Tuesday with another repeater and the 8924c to check it out. 
I'll be looking to see what comes down the antenna. If there are no big signals 
that shouldn't be there, and we can see/hear the paging on channel, and I there 
is no activity on 151.14 (actually 151.145 is San Bernardino County) or 170.94 
(ULS FCC DB shows nothing) then I'll assume it's a spur. 

I have talked to the tech and he was friendly. I'm going to contact him again 
and see if he will come up the hill with us and inspect his transmitter. 
 
--
Tim
:wq

On Aug 21, 2010, at 12:59 PM, MCH wrote:

 There is something wrong with your SM, then, as it should not show a 
 deviation of 15 kHz on a signal that is 15 kHz P-P unless it's only 
 deviating in one direction from the carrier.
 
 The +/- 4 kHz sounds about right. But, it should be centered around the 
 carrier frequency of 157.740 (Or, on 157.736 and 157.744). It would also 
 equate to a P-P of about 8 kHz as there is nothing but a shifted carrier 
 involved.
 
 Regardless, I suspect none of this relates to your problem.
 
 If it's only 75 yards from you, I bet it's a very weak spur. It's likely 
 down far enough that it's legal, too. If that is the case, the only 
 thing that will solve it is putting a filter on its TX to notch your 
 repeater RX frequency (good luck getting that to happen if it's not on 
 the same site - and often if it is on the same site).
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 My service monitor (HP 8924C) has both a deviation meter and an 
 oscilloscope to display the demodulated audio. Both the numbers on the 
 dev meter and the peak to peak on the scope read about 15 Khz.  
 
 I see another paging system (152.84) that shows the same 15 Khz dev, and 
 a bunch of other ones that show 5 Khz dev.
 
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 12:18 PM, MCH wrote:
 
 
 
 Before you said 15 kHz P-P (IOW bandwidth). Now you're saying 15 kHz
 deviation. 15 kHz deviation would be way too high.
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 I haven't noticed a hum. There's more of a scream on it.
 
 It's POCSAG. Is that analog?
 
 The dev is basically 15 Khz but there is, what I going to call splatter
 that is like 30 Khz.
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 10:14 AM, MCH wrote:
 
 
 
 Many times (but not all), there will be a grungy sound with the spur.
 Think of a very loud 60 cycle hum.
 
 And 15 kHz is higher than normal. I think the typical shift is 5 kHz
 (+/- 2.5 kHz) if we are talking about digital paging. Analog might 
 be 15
 kHz, as the bandwidth limit would be 16 kHz.
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 I'm not sure what you mean by grungy. What are you getting at?
 --
 Tim
 :wq
 
 On Aug 21, 2010, at 6:59 AM, MCH wrote:
 
 Does it have a 'grungy' sound to it when you hear it on your input?
 
 
 
 
 
 
 
 
 
 
 
 --
 
 
 Internal Virus Database is out of date.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: 
 03/14/10 03:33:00
 
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

Apparently, from what the tech said, this one is slated to go off the air in 
coming months, too. But I can't wait that long as our repeater is basically 
useless at this point. And you never know, it might take them longer than that 
to actually kill it. 
--
Tim
:wq

On Aug 21, 2010, at 1:02 PM, MCH wrote:

 One bright side: Paging companies are going the way of the dinosaur, so 
 it may not be on the air much longer. There used to be a couple dozen 
 paging companies in my area. Now there are 5 or 6 left - mostly on UHF/900.

Re: [Repeater-Builder] Re: Intermod Calculation

[men...@pa.net]

How long has the pager been in operation?
If it has been there for a long time either something changed in the  
pager setup or something changed on your end.

What you have is a case of RF overload.  No other frequencies are  
involved, not even your own transmitter.

225 watts RF + how much antenna gain on the pager end or is that the  
total ERP of the pager?

What is the difference in vertical height between the pager transmit  
antenna and your repeater antenna?

What sort of filtering are you using?  Duplexer?  Dual antennas?

The HP8924 in the Spectrum Analyser mode will show you the transmitted  
frequency shifting between the upper and lower limits.  The deviation  
measurement will be useless since you are not measuring deviation of  
an analog signal.  Setting up a digital paging transmitter usually  
involves activating a test mode which will place the unmodulated TX  
signal at the the limits.  The adjustment is made to set the amount of  
shift from the center channel according to the enginnering for the  
system.  When the incoming signal from the paging terminal is received  
it causes the transmitter to shift to one of the two limits which can  
be thought of as a 1 or a 0.  Ironically the systems I saw usually  
used AFSK on the link from the paging terminal (modem to modem).

If there is more than one transmitter involved measuring off the air  
cannot give you an accurate deviation measurement since any  
hetrodyne between the two or more carriers will also be seen by the  
service monitor and will distort the measurement.


Milt
N3LTQ


Quoting Tim Sawyer tisaw...@gmail.com:

 I have noticed the carrier appears to jump between +4 and -4 Khz of center.

 The transmitter is about 75 yards from me. It's running 225 watts  
 according to the tech.

 The interference is pretty strong. It competes with my base station  
 on low power. I'm 25 miles from the repeater.
 --
 Tim
 :wq

 On Aug 21, 2010, at 11:25 AM, men...@pa.net wrote:

 Tim,

 Digital paging (mostly POCSAG coding these days) is FSK and will
 easily occupy 15KHz of bandwidth.

 On a Service Monitor deviation screen you will see a square wave
 pattern that looks like it is overdeviated unless you are very close
 to the transmitter in question. Read on and you will see why a
 deviation measurement is of little use.

 On a Spectrum Analyser you will see a single spike that jumps back and
 forth between a freq higher than the channel center and a freq lower
 than the channel center. The typical digital paging transmitter
 settings are +4KHz above the assigned freq and - 4KHz below the
 assigned freq. If the system uses multiple transmitters the + and -
 settings may be asymmetrical to allow for slight offsets between
 transmitters. As demodulated at the paging receiver the signal is a
 1200 baud pattern of square waves.

 Newer systems such as FLEX may have two levels of + and - with
 settings of say +4K +2K -2K and -4K.

 If the problem is the digital paging transmitter you need to determine
 how close the transmitter is to your installation. Paging receivers
 represent a compromised antenna system and most paging transmitters
 compensate for the shortcomings of the receiver by sending at very
 high power levels. If the paging transmitter is close to you, it
 might be meeting spec but the low level grundge could be causing you
 problems.

 Milt
 N3LTQ

 Quoting Tim Sawyer tisaw...@gmail.com:

  I'm looking at the pager freq with the SA. The dev looks wide to me.
  I see about 15 Khz peak to peak. Is that normal?
 
  Also I see much bigger spikes.
 
  --
  Tim
  :wq
 
  On Aug 21, 2010, at 6:59 AM, MCH wrote:
 
  Again, just like a spur.
 
  Does it have a 'grungy' sound to it when you hear it on your input?
 
  Might also be worth putting the Spectrum Analyzer on your input to see
  if you can see it drifting through the frequency - or drifting onto it.
 
  Joe M.
 
  Tim Sawyer wrote:
   Another tidbit about this problem is that it's clean in the
  mornings. The paging transmitter can be going off like crazy and
  the repeater will be totally clean in carrier squelch. As the day
  progresses it gets worse.
   --
   Tim
   :wq
  
   On Aug 20, 2010, at 7:51 PM, Chuck Kelsey wrote:
  
   I agree, if you don't hear anything else in the mix, and it  
 pretty much
   happens for the full length of the page, it's likely a spur  
 on the paging
   transmitter, at least that's what I'd be looking at.
  
   Chuck
   WB2EDV
  
  
  
   - Original Message -
   From: MCH m...@nb.net
   To: Repeater-Builder@yahoogroups.com
   Sent: Friday, August 20, 2010 10:46 PM
   Subject: Re: [Repeater-Builder] Re: Intermod Calculation
  
  
   Could be a spur. Can you hear any other audio with the page? (ever)
  
   Joe M.
  
   Tim Sawyer wrote:
  
   It seems to pick up most of the page. Occasionally the beginning is
   missing or it will get just the very end. It always seems to
  drop at the
   same time as the page.
  
   --
   Tim
   :wq

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

If that was the issue I'd think every other two meter repeater on the hill (and 
there are many) would have the my same problem. But they don't. 
--
Tim
:wq

On Aug 21, 2010, at 7:27 PM, larynl2 wrote:

 
 
 --- In Repeater-Builder@yahoogroups.com, Tim Sawyer tisaw...@... wrote:
 
  
  Basically, there is one controller for both the 929.0375 and the 157.74 
  transmitters. They also have two other transmitters on 929.6375 and 
  931.6625.
 
 Are the 929.0375 and 929.6375 transmitters at the same site as your repeater? 
 I'm seeing 600 kc. difference there...
 
 Laryn K8TVZ
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

On Aug 21, 2010, at 6:38 PM, men...@pa.net wrote:

 How long has the pager been in operation?
 If it has been there for a long time either something changed in the 
 pager setup or something changed on your end.
 
 
We've been having many problems at the site (including a broken tower cross 
arm, now fixed) for a while now and lots of things have been changing. I'm 
aware that it could be our problem as likely as theirs.  We've been up there 
for 30 years, don't know how long they have been there, certianly longer than 
this problem.

 What you have is a case of RF overload. No other frequencies are 
 involved, not even your own transmitter.
 
 
I'm thinking spurious pager TX , not our RX overload at this point. But I'm 
going to go have a look at things. 

 225 watts RF + how much antenna gain on the pager end or is that the 
 total ERP of the pager?
 
 
That's power out of the transmitter. I think they are allowed 999 watts ERP but 
I don't know what theirs is.  

 What is the difference in vertical height between the pager transmit 
 antenna and your repeater antenna?
 
 
Our antenna is a little higher and about 75 yards away.

 What sort of filtering are you using? Duplexer? Dual antennas?
 
 
Split TX/RX antennas about 40 feet apart with near straight vertical 
separation. Six cavity BP/BR duplexer plus two bottle Wacom filter on the RX. 
TX has a 3 pole circulator and low pass filter. 

 The HP8924 in the Spectrum Analyser mode will show you the transmitted 
 frequency shifting between the upper and lower limits. The deviation 
 measurement will be useless since you are not measuring deviation of 
 an analog signal. Setting up a digital paging transmitter usually 
 involves activating a test mode which will place the unmodulated TX 
 signal at the the limits. The adjustment is made to set the amount of 
 shift from the center channel according to the enginnering for the 
 system. When the incoming signal from the paging terminal is received 
 it causes the transmitter to shift to one of the two limits which can 
 be thought of as a 1 or a 0. Ironically the systems I saw usually 
 used AFSK on the link from the paging terminal (modem to modem).
 
 
Yea, ok. I'm not that familiar with what these paging systems look like on the 
SA. It looked odd to me. But the consensus here seems to be that dev is ok. I 
did see another paging system with this same looking modulation. 

 If there is more than one transmitter involved measuring off the air 
 cannot give you an accurate deviation measurement since any 
 hetrodyne between the two or more carriers will also be seen by the 
 service monitor and will distort the measurement.
 
 
They do have more than 1 transmitter. I can't tell for sure if I can hear more 
than one. It's possible.

 

Re: [Repeater-Builder] Re: Intermod Calculation

[Chuck Kelsey]

Does the entire page happen, or does it abruptly stop part way through some 
of the time? Partial page would indicate to me that another transmitter is 
in the mix and dropping before the pager does.

However, I had a situation where there were four paging sites scattered in 
the county on the same frequency and one of the transmitters was spurious 
and getting into my receiver. In that case, I always heard the entire page, 
but only when that particular transmitter came up.

Chuck
WB2EDV


- Original Message - 
From: Tim - WD6AWP tisaw...@gmail.com
To: Repeater-Builder@yahoogroups.com
Sent: Friday, August 20, 2010 7:27 PM
Subject: [Repeater-Builder] Re: Intermod Calculation


 It occurs whether or not the repeater transmitter is keyed.

 --- In Repeater-Builder@yahoogroups.com, Jeff DePolo j...@... wrote:


 Before we get into the math, an important question that needs to be 
 answered
 is whether or not this mix occurs when your repeater transmitter is 
 unkeyed.


 --- Jeff WN3A

  -Original Message-
  From: Repeater-Builder@yahoogroups.com
  [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
  Sent: Friday, August 20, 2010 6:36 PM
  To: Repeater-Builder@yahoogroups.com
  Subject: [Repeater-Builder] Intermod Calculation
 
 
 
  I have paging intermod from 157.740 Mhz. My receiver is on
  144.540 Mhz. I'm 100% sure there is another transmitter
  involved in the mix because sometimes the pager is
  transmitting and I have no interference.
 
  I have an intermod calculator program but it wants all the
  known transmitters and the target receiver. But I need to
  solve for an unknown transmitter. Is there a way to calculate
  the other possible soruce(s)?
  --
  Tim
  :wq
 
 
 
 
 





 



 Yahoo! Groups Links









No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10 
14:35:00

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

It seems to pick up most of the page. Occasionally the beginning is missing or 
it will get just the very end. It always seems to drop at the same time as the 
page. 

--
Tim
:wq

On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:

 Does the entire page happen, or does it abruptly stop part way through some 
 of the time? Partial page would indicate to me that another transmitter is 
 in the mix and dropping before the pager does.
 
 However, I had a situation where there were four paging sites scattered in 
 the county on the same frequency and one of the transmitters was spurious 
 and getting into my receiver. In that case, I always heard the entire page, 
 but only when that particular transmitter came up.
 
 Chuck
 WB2EDV
 
 - Original Message - 
 From: Tim - WD6AWP tisaw...@gmail.com
 To: Repeater-Builder@yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation
 
  It occurs whether or not the repeater transmitter is keyed.
 
  --- In Repeater-Builder@yahoogroups.com, Jeff DePolo j...@... wrote:
 
 
  Before we get into the math, an important question that needs to be 
  answered
  is whether or not this mix occurs when your repeater transmitter is 
  unkeyed.
 
 
  --- Jeff WN3A
 
   -Original Message-
   From: Repeater-Builder@yahoogroups.com
   [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
   Sent: Friday, August 20, 2010 6:36 PM
   To: Repeater-Builder@yahoogroups.com
   Subject: [Repeater-Builder] Intermod Calculation
  
  
  
   I have paging intermod from 157.740 Mhz. My receiver is on
   144.540 Mhz. I'm 100% sure there is another transmitter
   involved in the mix because sometimes the pager is
   transmitting and I have no interference.
  
   I have an intermod calculator program but it wants all the
   known transmitters and the target receiver. But I need to
   solve for an unknown transmitter. Is there a way to calculate
   the other possible soruce(s)?
   --
   Tim
   :wq
  
  
  
  
  
 
 
 
 
 
  
 
 
 
  Yahoo! Groups Links
 
 
 
 
 --
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10 
 14:35:00
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[MCH]

Could be a spur. Can you hear any other audio with the page? (ever)

Joe M.

Tim Sawyer wrote:
 
 
 It seems to pick up most of the page. Occasionally the beginning is 
 missing or it will get just the very end. It always seems to drop at the 
 same time as the page. 
 
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
  

 Does the entire page happen, or does it abruptly stop part way through 
 some
 of the time? Partial page would indicate to me that another 
 transmitter is
 in the mix and dropping before the pager does.

 However, I had a situation where there were four paging sites 
 scattered in
 the county on the same frequency and one of the transmitters was spurious
 and getting into my receiver. In that case, I always heard the entire 
 page,
 but only when that particular transmitter came up.

 Chuck
 WB2EDV

 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation

  It occurs whether or not the repeater transmitter is keyed.
 
  --- In Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@... 
 wrote:
 
 
  Before we get into the math, an important question that needs to be
  answered
  is whether or not this mix occurs when your repeater transmitter is
  unkeyed.
 
 
  --- Jeff WN3A
 
   -Original Message-
   From: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
   [mailto:Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
   Sent: Friday, August 20, 2010 6:36 PM
   To: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
   Subject: [Repeater-Builder] Intermod Calculation
  
  
  
   I have paging intermod from 157.740 Mhz. My receiver is on
   144.540 Mhz. I'm 100% sure there is another transmitter
   involved in the mix because sometimes the pager is
   transmitting and I have no interference.
  
   I have an intermod calculator program but it wants all the
   known transmitters and the target receiver. But I need to
   solve for an unknown transmitter. Is there a way to calculate
   the other possible soruce(s)?
   --
   Tim
   :wq
  
  
  
  
  
 
 
 
 
 
  
 
 
 
  Yahoo! Groups Links
 
 
 

 --

 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
 14:35:00

 
 
 
 






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Re: [Repeater-Builder] Re: Intermod Calculation

[Chuck Kelsey]

I agree, if you don't hear anything else in the mix, and it pretty much 
happens for the full length of the page, it's likely a spur on the paging 
transmitter, at least that's what I'd be looking at.

Chuck
WB2EDV



- Original Message - 
From: MCH m...@nb.net
To: Repeater-Builder@yahoogroups.com
Sent: Friday, August 20, 2010 10:46 PM
Subject: Re: [Repeater-Builder] Re: Intermod Calculation


 Could be a spur. Can you hear any other audio with the page? (ever)

 Joe M.

 Tim Sawyer wrote:


 It seems to pick up most of the page. Occasionally the beginning is
 missing or it will get just the very end. It always seems to drop at the
 same time as the page.

 --
 Tim
 :wq

 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:



 Does the entire page happen, or does it abruptly stop part way through
 some
 of the time? Partial page would indicate to me that another
 transmitter is
 in the mix and dropping before the pager does.

 However, I had a situation where there were four paging sites
 scattered in
 the county on the same frequency and one of the transmitters was 
 spurious
 and getting into my receiver. In that case, I always heard the entire
 page,
 but only when that particular transmitter came up.

 Chuck
 WB2EDV

 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation

  It occurs whether or not the repeater transmitter is keyed.
 
  --- In Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@...
 wrote:
 
 
  Before we get into the math, an important question that needs to be
  answered
  is whether or not this mix occurs when your repeater transmitter is
  unkeyed.
 
 
  --- Jeff WN3A
 
   -Original Message-
   From: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
   [mailto:Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
   Sent: Friday, August 20, 2010 6:36 PM
   To: Repeater-Builder@yahoogroups.com
 mailto:Repeater-Builder%40yahoogroups.com
   Subject: [Repeater-Builder] Intermod Calculation
  
  
  
   I have paging intermod from 157.740 Mhz. My receiver is on
   144.540 Mhz. I'm 100% sure there is another transmitter
   involved in the mix because sometimes the pager is
   transmitting and I have no interference.
  
   I have an intermod calculator program but it wants all the
   known transmitters and the target receiver. But I need to
   solve for an unknown transmitter. Is there a way to calculate
   the other possible soruce(s)?
   --
   Tim
   :wq
  
  
  
  
  
 
 
 
 
 
  
 
 
 
  Yahoo! Groups Links
 
 
 

 --

 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
 14:35:00







 



 Yahoo! Groups Links









No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10 
14:35:00







Yahoo! Groups Links

* To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/

* Your email settings:
Individual Email | Traditional

* To change settings online go to:
http://groups.yahoo.com/group/Repeater-Builder/join
(Yahoo! ID required)

* To change settings via email:
repeater-builder-dig...@yahoogroups.com 
repeater-builder-fullfeatu...@yahoogroups.com

* To unsubscribe from this group, send an email to:
repeater-builder-unsubscr...@yahoogroups.com

* Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

No, I never, ever have heard any other audio. But there is time when I don't 
hear it at all... as if it takes two signals to occur. 

--
Tim
:wq

On Aug 20, 2010, at 7:46 PM, MCH wrote:

 Could be a spur. Can you hear any other audio with the page? (ever)
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 It seems to pick up most of the page. Occasionally the beginning is 
 missing or it will get just the very end. It always seems to drop at the 
 same time as the page. 
 
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
 
 
 Does the entire page happen, or does it abruptly stop part way through 
 some
 of the time? Partial page would indicate to me that another 
 transmitter is
 in the mix and dropping before the pager does.
 
 However, I had a situation where there were four paging sites 
 scattered in
 the county on the same frequency and one of the transmitters was spurious
 and getting into my receiver. In that case, I always heard the entire 
 page,
 but only when that particular transmitter came up.
 
 Chuck
 WB2EDV
 
 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation
 
 It occurs whether or not the repeater transmitter is keyed.
 
 --- In Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@... 
 wrote:
 
 
 Before we get into the math, an important question that needs to be
 answered
 is whether or not this mix occurs when your repeater transmitter is
 unkeyed.
 
 
 --- Jeff WN3A
 
 -Original Message-
 From: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
 [mailto:Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Friday, August 20, 2010 6:36 PM
 To: Repeater-Builder@yahoogroups.com 
 mailto:Repeater-Builder%40yahoogroups.com
 Subject: [Repeater-Builder] Intermod Calculation
 
 
 
 I have paging intermod from 157.740 Mhz. My receiver is on
 144.540 Mhz. I'm 100% sure there is another transmitter
 involved in the mix because sometimes the pager is
 transmitting and I have no interference.
 
 I have an intermod calculator program but it wants all the
 known transmitters and the target receiver. But I need to
 solve for an unknown transmitter. Is there a way to calculate
 the other possible soruce(s)?
 --
 Tim
 :wq
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 --
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
 14:35:00
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 

RE: [Repeater-Builder] Re: Intermod Calculation

[Mike Besemer (WM4B)]

Tim,

 

Where are you located?

 

73,

 

Mike

WM4B

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
Sent: Friday, August 20, 2010 11:49 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Intermod Calculation

 

  

No, I never, ever have heard any other audio. But there is time when I don't
hear it at all... as if it takes two signals to occur. 

--
Tim
:wq

On Aug 20, 2010, at 7:46 PM, MCH wrote:

 Could be a spur. Can you hear any other audio with the page? (ever)
 
 Joe M.
 
 Tim Sawyer wrote:
 
 
 It seems to pick up most of the page. Occasionally the beginning is 
 missing or it will get just the very end. It always seems to drop at the 
 same time as the page. 
 
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
 
 
 
 Does the entire page happen, or does it abruptly stop part way through 
 some
 of the time? Partial page would indicate to me that another 
 transmitter is
 in the mix and dropping before the pager does.
 
 However, I had a situation where there were four paging sites 
 scattered in
 the county on the same frequency and one of the transmitters was
spurious
 and getting into my receiver. In that case, I always heard the entire 
 page,
 but only when that particular transmitter came up.
 
 Chuck
 WB2EDV
 
 - Original Message -
 From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
mailto:tisawyer%40gmail.com
 To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com
 Sent: Friday, August 20, 2010 7:27 PM
 Subject: [Repeater-Builder] Re: Intermod Calculation
 
 It occurs whether or not the repeater transmitter is keyed.
 
 --- In Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@... 
 wrote:
 
 
 Before we get into the math, an important question that needs to be
 answered
 is whether or not this mix occurs when your repeater transmitter is
 unkeyed.
 
 
 --- Jeff WN3A
 
 -Original Message-
 From: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com
 [mailto:Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Friday, August 20, 2010 6:36 PM
 To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com  
 mailto:Repeater-Builder%40yahoogroups.com
 Subject: [Repeater-Builder] Intermod Calculation
 
 
 
 I have paging intermod from 157.740 Mhz. My receiver is on
 144.540 Mhz. I'm 100% sure there is another transmitter
 involved in the mix because sometimes the pager is
 transmitting and I have no interference.
 
 I have an intermod calculator program but it wants all the
 known transmitters and the target receiver. But I need to
 solve for an unknown transmitter. Is there a way to calculate
 the other possible soruce(s)?
 --
 Tim
 :wq
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 
 
 --
 
 No virus found in this incoming message.
 Checked by AVG - www.avg.com http://www.avg.com
 Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
 14:35:00
 
 
 
 
 
 
 
 
 
 
 
 Yahoo! Groups Links
 
 
 

Re: [Repeater-Builder] Re: Intermod Calculation

[Tim Sawyer]

I'm in Huntington Beach.
--
Tim
:wq

On Aug 20, 2010, at 8:52 PM, Mike Besemer (WM4B) wrote:

 
 Tim,
 
  
 
 Where are you located?
 
  
 
 73,
 
  
 
 Mike
 
 WM4B
 
  
 
 From: Repeater-Builder@yahoogroups.com 
 [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Sawyer
 Sent: Friday, August 20, 2010 11:49 PM
 To: Repeater-Builder@yahoogroups.com
 Subject: Re: [Repeater-Builder] Re: Intermod Calculation
 
  
 
  
 
 No, I never, ever have heard any other audio. But there is time when I don't 
 hear it at all... as if it takes two signals to occur. 
 
 --
 Tim
 :wq
 
 On Aug 20, 2010, at 7:46 PM, MCH wrote:
 
  Could be a spur. Can you hear any other audio with the page? (ever)
  
  Joe M.
  
  Tim Sawyer wrote:
  
  
  It seems to pick up most of the page. Occasionally the beginning is 
  missing or it will get just the very end. It always seems to drop at the 
  same time as the page. 
  
  --
  Tim
  :wq
  
  On Aug 20, 2010, at 4:38 PM, Chuck Kelsey wrote:
  
  
  
  Does the entire page happen, or does it abruptly stop part way through 
  some
  of the time? Partial page would indicate to me that another 
  transmitter is
  in the mix and dropping before the pager does.
  
  However, I had a situation where there were four paging sites 
  scattered in
  the county on the same frequency and one of the transmitters was spurious
  and getting into my receiver. In that case, I always heard the entire 
  page,
  but only when that particular transmitter came up.
  
  Chuck
  WB2EDV
  
  - Original Message -
  From: Tim - WD6AWP tisaw...@gmail.com mailto:tisawyer%40gmail.com
  To: Repeater-Builder@yahoogroups.com 
  mailto:Repeater-Builder%40yahoogroups.com
  Sent: Friday, August 20, 2010 7:27 PM
  Subject: [Repeater-Builder] Re: Intermod Calculation
  
  It occurs whether or not the repeater transmitter is keyed.
  
  --- In Repeater-Builder@yahoogroups.com 
  mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@... 
  wrote:
  
  
  Before we get into the math, an important question that needs to be
  answered
  is whether or not this mix occurs when your repeater transmitter is
  unkeyed.
  
  
  --- Jeff WN3A
  
  -Original Message-
  From: Repeater-Builder@yahoogroups.com 
  mailto:Repeater-Builder%40yahoogroups.com
  [mailto:Repeater-Builder@yahoogroups.com 
  mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tim Sawyer
  Sent: Friday, August 20, 2010 6:36 PM
  To: Repeater-Builder@yahoogroups.com 
  mailto:Repeater-Builder%40yahoogroups.com
  Subject: [Repeater-Builder] Intermod Calculation
  
  
  
  I have paging intermod from 157.740 Mhz. My receiver is on
  144.540 Mhz. I'm 100% sure there is another transmitter
  involved in the mix because sometimes the pager is
  transmitting and I have no interference.
  
  I have an intermod calculator program but it wants all the
  known transmitters and the target receiver. But I need to
  solve for an unknown transmitter. Is there a way to calculate
  the other possible soruce(s)?
  --
  Tim
  :wq
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  Yahoo! Groups Links
  
  
  
  
  --
  
  No virus found in this incoming message.
  Checked by AVG - www.avg.com http://www.avg.com
  Version: 9.0.851 / Virus Database: 271.1.1/3084 - Release Date: 08/20/10
  14:35:00
  
  
  
  
  
  
  
  
  
  
  
  Yahoo! Groups Links