RE: [Repeater-Builder] Noise Level on a Duplexer

[Eric Vincent]

Hello Kent,

 

Everybody go in the same trail but not at the same time…  

Many year ago I have had a trouble and similar than yours, a Q202 duplexer
refuse to work properly and my final approach was to replace all the N type
T connectors by new one, good one, silver plated with real Mil spec and our
problem disappear.

 

Some T adaptor use a little spring in between the line to do contact on the
center pin of the T, these type are so cheap and they are made by Provo.
(Please, NEVER USE THAT KIND OF ... )

 

I hope this help you a little bit...

73’ Eric VE2VXT / VE7YBC

 

  _  

De : Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] De la part de Kent Chong
Envoyé : 10 mars 2010 07:12
À : Repeater-Builder@yahoogroups.com
Objet : Re: [Repeater-Builder] Noise Level on a Duplexer

 

  


Dear Eric,

Thank you for your mail.

Yes, we found that the interconnect T-Join between two system is heated up.
Could we just cool down the T-Join for there is other way to solve this
issue?

Best Regards,

Kent

--- On Wed, 10/3/10, Eric Lowell  wrote:


From: Eric Lowell 
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
To: Repeater-Builder@yahoogroups.com
Date: Wednesday, 10 March, 2010, 8:54 PM

  

Kent, 

 

I have seen this sort of problem before in a simaler application. I believe
that your duplexer may have a bad internal connection, possibly at a
fingerstock contact. In my case the problem was solved by replacing the
duplexer. I believe the problem was caused by tuning the duplexer under
power rather than with a network analyser. This occured many years ago, so
my memory may be faulty.

 

Best Regards de Eric (W1EL)
 

Eric Lowell
Eastern Maine Electronics Inc.
48 Loon Road
Wesley ME 04686
eme@starband. net
www.satnetmaine. com
207-210-7469 

 

 

  _  

From: Kent Chong 
To: Repeater-Builder@ yahoogroups. com
Sent: Tue, March 9, 2010 10:31:30 AM
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer

  


Dear Joe,

Yes, we have observed the signal with a spectrum analyser. It is a broadband
noise covering our entire TETRA band.

Yes, the transmitter is keyed up continually. 

Regarding oscillation, what circuitry will develop the oscillation in 3
days? We are thinking about the heat problem too, as heat may be developed
overtime.

Best Regards,

Kent



--- On Tue, 9/3/10, Joe  wrote:


From: Joe 
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
To: Repeater-Builder@ yahoogroups. com
Date: Tuesday, 9 March, 2010, 8:52 PM

  

Hello Kent,

Have you looked at the noise on a spectrum analyzer? Is is broadbanded 
noise, or is it just on your receiver frequencies? If it is only on 
specific frequencies, is it frequency stable or does it drift around? 

Also, do any of your transmitters stay constantly keyed up?

I'm wondering if something external to your system is oscillating. Your 
signals may be causing it to go into self-oscillation. When you shut 
your system off it stops. This is just a guess right now.

73, Joe, K1ike

>
>
> <http://sg.rd. yahoo.com/ sg/mail/domainch oice/mail/
<http://sg.rd.yahoo.com/sg/mail/domainchoice/mail/signature/*http:/mail.prom
otions.yahoo.com/newdomains/sg/>  signature/ *http://mail. promotions.
yahoo.com/ newdomains/ sg/>

 

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otions.yahoo.com/newdomains/sg/> 
Grab the Email name you've always wanted before someone else does! 

 

 

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Re: [Repeater-Builder] Noise Level on a Duplexer

[Kris Kirby]

On Wed, 10 Mar 2010, Kent Chong wrote:
> Yes, we found that the interconnect T-Join between two system is 
> heated up. Could we just cool down the T-Join for there is other way 
> to solve this issue?

Replace the tee. It has failed, or one of the connectors attached to the 
coax has failed and the heat is conducting into the tee. 

--
Kris Kirby, KE4AHR
Disinformation Analyst

Re: [Repeater-Builder] Noise Level on a Duplexer

[Kent Chong]

Dear Eric,

Thank you for your mail.

Yes, we found that the interconnect T-Join between two system is heated up. 
Could we just cool down the T-Join for there is other way to solve this issue?

Best Regards,

Kent

--- On Wed, 10/3/10, Eric Lowell  wrote:

From: Eric Lowell 
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
To: Repeater-Builder@yahoogroups.com
Date: Wednesday, 10 March, 2010, 8:54 PM







 



  



  
  
  
Kent, 
 
I have seen this sort of problem before in a simaler application. I believe 
that your duplexer may have a bad internal connection, possibly at a 
fingerstock contact. In my case the problem was solved by replacing the 
duplexer. I believe the problem was caused by tuning the duplexer under power 
rather than with a network analyser. This occured many years ago, so my memory 
may be faulty.
 
Best Regards de Eric (W1EL)
 Eric Lowell
Eastern Maine Electronics Inc.
48 Loon Road
Wesley ME 04686
eme@starband. net
www.satnetmaine. com
207-210-7469 






From: Kent Chong 
To: Repeater-Builder@ yahoogroups. com
Sent: Tue, March 9, 2010 10:31:30 AM
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer

  





Dear Joe,

Yes, we have observed the signal with a spectrum analyser. It is a broadband 
noise covering our entire TETRA band.

Yes, the transmitter is keyed up continually. 

Regarding oscillation, what circuitry will develop the oscillation in 3 days? 
We are thinking about the heat problem too, as heat may be developed overtime.

Best Regards,

Kent



--- On Tue, 9/3/10, Joe  wrote:


From: Joe 
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
To: Repeater-Builder@ yahoogroups. com
Date: Tuesday, 9 March, 2010, 8:52 PM


  

Hello Kent,

Have you looked at the noise on a spectrum analyzer? Is is broadbanded 
noise, or is it just on your receiver frequencies? If it is only on 
specific frequencies, is it frequency stable or does it drift around? 

Also, do any of your transmitters stay constantly keyed up?

I'm wondering if something external to your system is oscillating. Your 
signals may be causing it to go into self-oscillation. When you shut 
your system off it stops. This is just a guess right now.

73, Joe, K1ike

>
>
> <http://sg.rd. yahoo.com/ sg/mail/domainch oice/mail/ signature/ 
> *http://mail. promotions. yahoo.com/ newdomains/ sg/>



Get your new Email address! 
Grab the Email name you've always wanted before someone else does! 





  


 





 



  






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Re: [Repeater-Builder] Noise Level on a Duplexer

[Eric Lowell]

Kent, 

I have seen this sort of problem before in a simaler application. I believe 
that your duplexer may have a bad internal connection, possibly at a 
fingerstock contact. In my case the problem was solved by replacing the 
duplexer. I believe the problem was caused by tuning the duplexer under power 
rather than with a network analyser. This occured many years ago, so my memory 
may be faulty.

Best Regards de Eric (W1EL)
 Eric Lowell
Eastern Maine Electronics Inc.
48 Loon Road
Wesley ME 04686
eme@starband.net
www.satnetmaine.com
207-210-7469 





From: Kent Chong 
To: Repeater-Builder@yahoogroups.com
Sent: Tue, March 9, 2010 10:31:30 AM
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer

  
Dear Joe,

Yes, we have observed the signal with a spectrum analyser. It is a broadband 
noise covering our entire TETRA band.

Yes, the transmitter is keyed up continually. 

Regarding oscillation, what circuitry will develop the oscillation in 3 days? 
We are thinking about the heat problem too, as heat may be developed overtime.

Best Regards,

Kent



--- On Tue, 9/3/10, Joe  wrote:


>From: Joe 
>Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
>To: Repeater-Builder@ yahoogroups. com
>Date: Tuesday, 9 March, 2010, 8:52 PM
>
>
>  
>Hello Kent,
>
>Have you looked at the noise on a spectrum analyzer? Is is broadbanded 
>noise, or is it just on your receiver frequencies? If it is only on 
>specific frequencies, is it frequency stable or does it drift around? 
>
>Also, do any of your transmitters stay constantly keyed up?
>
>I'm wondering if something external to your system is oscillating. Your 
>signals may be causing it to go into self-oscillation. When you shut 
>your system off it stops. This is just a guess right now.
>
>73, Joe, K1ike
>
>>
>>
>> <http://sg.rd. yahoo.com/ sg/mail/domainch oice/mail/ signature/ 
>> *http://mail. promotions. yahoo.com/ newdomains/ sg/>
> 


Get your new Email address! 
Grab the Email name you've always wanted before someone else does! 



  

Re: [Repeater-Builder] Noise Level on a Duplexer

[Kent Chong]

Dear Joe,

Yes, we have observed the signal with a spectrum analyser. It is a broadband 
noise covering our entire TETRA band.

Yes, the transmitter is keyed up continually. 

Regarding oscillation, what circuitry will develop the oscillation in 3 days? 
We are thinking about the heat problem too, as heat may be developed overtime.

Best Regards,

Kent



--- On Tue, 9/3/10, Joe  wrote:

From: Joe 
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
To: Repeater-Builder@yahoogroups.com
Date: Tuesday, 9 March, 2010, 8:52 PM







 



  



  
  
  Hello Kent,



Have you looked at the noise on a spectrum analyzer?  Is is broadbanded 

noise, or is it just on your receiver frequencies?  If it is only on 

specific frequencies, is it frequency stable or does it drift around? 



Also, do any of your transmitters stay constantly keyed up?



I'm wondering if something external to your system is oscillating.  Your 

signals may be causing it to go into self-oscillation.  When you shut 

your system off it stops.  This is just a guess right now.



73, Joe, K1ike



>

>

> <http://sg.rd. yahoo.com/ sg/mail/domainch oice/mail/ signature/ 
> *http://mail. promotions. yahoo.com/ newdomains/ sg/>




 





 



  






  

Re: [Repeater-Builder] Noise Level on a Duplexer

[Joe]

Hello Kent,

Have you looked at the noise on a spectrum analyzer?  Is is broadbanded 
noise, or is it just on your receiver frequencies?  If it is only on 
specific frequencies, is it frequency stable or does it drift around? 

Also, do any of your transmitters stay constantly keyed up?

I'm wondering if something external to your system is oscillating.  Your 
signals may be causing it to go into self-oscillation.  When you shut 
your system off it stops.  This is just a guess right now.

73, Joe, K1ike


>
>
> 

Re: [Repeater-Builder] Noise Level on a Duplexer

[Kent Chong]

Dear Nate,

They are TETRA & TETRAPOL systems. It seems like our Duplexer that is causing 
the problem, as the TETRA system bypasses the Combiner, the noise is removed.

At first, we were thinking it is the heat problem, but the system is installed 
in an air-condition room at 25 deg C, and the Duplexer is not heated up.

Best Regards,

Kent

--- On Tue, 9/3/10, Nate Duehr  wrote:

From: Nate Duehr 
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
To: Repeater-Builder@yahoogroups.com
Date: Tuesday, 9 March, 2010, 6:08 AM







 



  



  
  
  



What specific radios, and would 3 hours be enough for the radios
themselves or any other components they might be heating to return to
room-temperature (whatever that is where they're installed)?



Nate WY0X



On 3/8/2010 10:03 AM, Kent Chong wrote:
 

  
  
  

  
Hello Everybody,



Good day.



We have developed a Duplexer to combine to two signals form two systems
for in-building application. The Dupluxer (or combiner) has
specifications of 1.7dB insertion loss and >60dB isolation. When we
set up the system and power on the two systems, the combiner works fine.



However, we notice that the noise level (up link) on the two systems
will slowly increase, and until 3~4 days later, the noise level has
increased to -80~-60dBm level. We then power down the systems for 3
hours, and power them up again. The systems work fine again.



Anybody could help?



Best Regards,



Kent


  

  
  
  
  
  









 





 



  






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Re: [Repeater-Builder] Noise Level on a Duplexer

[Kent Chong]

Dear Joe,

One system is on 380~400Mhz, and the other one is on 470~490Mhz.

Best Regards,

Kent

--- On Tue, 9/3/10, Joe  wrote:

From: Joe 
Subject: Re: [Repeater-Builder] Noise Level on a Duplexer
To: Repeater-Builder@yahoogroups.com
Date: Tuesday, 9 March, 2010, 7:29 AM







 



  



  
  
  What frequency are you on?



Joe



Kent Chong wrote:

>

>

> Hello Everybody,

>

> Good day.

>

> We have developed a Duplexer to combine to two signals form two 

> systems for in-building application. The Dupluxer (or combiner) has 

> specifications of 1.7dB insertion loss and >60dB isolation. When we 

> set up the system and power on the two systems, the combiner works fine.

>

> However, we notice that the noise level (up link) on the two systems 

> will slowly increase, and until 3~4 days later, the noise level has 

> increased to -80~-60dBm level. We then power down the systems for 3 

> hours, and power them up again. The systems work fine again.

>

> Anybody could help?

>

> Best Regards,

>

> Kent

>

>

>

>  - - - - - -

> New Email names for you! 

> <http://sg.rd. yahoo.com/ sg/mail/domainch oice/mail/ signature/ 
> *http://mail. promotions. yahoo.com/ newdomains/ sg/> 

>

> Get the Email name you've always wanted on the new @ymail and @rocketmail.

> Hurry before someone else does!

>

> 






 





 



  






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Re: [Repeater-Builder] Noise Level on a Duplexer

[Joe]

What frequency are you on?

Joe

Kent Chong wrote:
>
>
> Hello Everybody,
>
> Good day.
>
> We have developed a Duplexer to combine to two signals form two 
> systems for in-building application. The Dupluxer (or combiner) has 
> specifications of 1.7dB insertion loss and >60dB isolation. When we 
> set up the system and power on the two systems, the combiner works fine.
>
> However, we notice that the noise level (up link) on the two systems 
> will slowly increase, and until 3~4 days later, the noise level has 
> increased to -80~-60dBm level. We then power down the systems for 3 
> hours, and power them up again. The systems work fine again.
>
> Anybody could help?
>
> Best Regards,
>
> Kent
>
>
>
> 
> New Email names for you! 
> 
>  
>
> Get the Email name you've always wanted on the new @ymail and @rocketmail.
> Hurry before someone else does!
>
> 

Re: [Repeater-Builder] Noise Level on a Duplexer

[Nate Duehr]

What specific radios, and would 3 hours be enough for the radios 
themselves or any other components they might be heating to return to 
room-temperature (whatever that is where they're installed)?


Nate WY0X

On 3/8/2010 10:03 AM, Kent Chong wrote:


Hello Everybody,

Good day.

We have developed a Duplexer to combine to two signals form two 
systems for in-building application. The Dupluxer (or combiner) has 
specifications of 1.7dB insertion loss and >60dB isolation. When we 
set up the system and power on the two systems, the combiner works fine.


However, we notice that the noise level (up link) on the two systems 
will slowly increase, and until 3~4 days later, the noise level has 
increased to -80~-60dBm level. We then power down the systems for 3 
hours, and power them up again. The systems work fine again.


Anybody could help?

Best Regards,

Kent

[Repeater-Builder] Noise Level on a Duplexer

[Kent Chong]

Hello Everybody,

Good day.

We have developed a Duplexer to combine to two signals form two systems for 
in-building application. The Dupluxer (or combiner) has specifications of 1.7dB 
insertion loss and >60dB isolation. When we set up the system and power on the 
two systems, the combiner works fine.

However, we notice that the noise level (up link) on the two systems will 
slowly increase, and until 3~4 days later, the noise level has increased to 
-80~-60dBm level. We then power down the systems for 3 hours, and power them up 
again. The systems work fine again.

Anybody could help?

Best Regards,

Kent







 



  






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Get the Email name you've always wanted on the new @ymail and @rocketmail. 
Hurry before someone else does!
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