RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Commercial, Professional Radio and Personal Radio > System Administration and Maintenance


System Administration and Maintenance - Here is where radio system managers can discuss some of the more intricate details of managing their complex radio systems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 05-01-2018, 3:49 AM
Member
   
Join Date: Dec 2008
Location: Phoenix, Arizona
Posts: 45
Default Decibel Products DB4140-2A VHF Notch Duplexer

I have been trying to locate a specification sheet for a Decibel Products DB4140-2A VHF Notch Duplexer. I'm interested in the frequency range, Minimum frequency separation and insertion loss. Normally I can find spec sheets for most DB Products duplexers but this one seems to be some what of a mystery.

Any information will be appreciated.
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 05-01-2018, 6:11 AM
buddrousa's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jan 2003
Location: NW Tenn
Posts: 4,123
Default

What is the intended input frequency and the intended output frequency?
The set on ebay from AZ Highway Department range from 150-156's and are very old. We had a set that worked 300Kz they were a lot larger and very expensive.
__________________
Support your local FIRE & EMS. PRO197-18-107-668:PSR-410 X2: BC8500XLT 785d BCD436HP BCD536HPx3 BCT346 BCD996P2 x3 BCT15x2 BCT15X2 TRX-1 TRX-2 EFJ51SL MTX8250 Tk280 TK2180 MD380x4 NX5300 NX5200 Buddy

Last edited by buddrousa; 05-01-2018 at 6:20 AM..
Reply With Quote
  #3 (permalink)  
Old 05-01-2018, 10:50 PM
Member
   
Join Date: Dec 2008
Location: Phoenix, Arizona
Posts: 45
Default

This is another duplexer than the one on E-Bay. The output frequency is 145.210 MHZ and the input frequency is 144.610.

Thank You
Reply With Quote
  #4 (permalink)  
Old 05-13-2018, 10:17 PM
chief21's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Mar 2004
Location: Summer - western NC mountains; Winter - central FL gulf coast
Posts: 645
Default

spec sheet here...

http://www.repeater-builder.com/ante...structions.pdf
Reply With Quote
  #5 (permalink)  
Old 05-14-2018, 9:16 AM
Member
   
Join Date: Sep 2008
Location: In the 'patch
Posts: 4,914
Default

Quote:
Originally Posted by chief21 View Post
That is not a spec sheet.
__________________
Interoperatablity is not a technology, it is an attitude!!!
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 05-14-2018, 3:03 PM
Member
   
Join Date: Dec 2008
Location: Phoenix, Arizona
Posts: 45
Default

Thank you for the information sheet. I think this confirms my suspicion that the duplexer was constructed of individual filters and not as a set by the manufacturer. It should still work but I would be more confident if they were a matched set.

Thank you again for all your posts.
Reply With Quote
  #7 (permalink)  
Old 05-14-2018, 4:17 PM
chief21's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Mar 2004
Location: Summer - western NC mountains; Winter - central FL gulf coast
Posts: 645
Default

I think the important distinction here is that this item is listed as a "Notch Filter" rather than a "Duplexer". A typical VHF Pass/Reject duplexer is much larger and usually consists of multiple filters. This device is a single filter and is apparently intended to notch out a single interfering signal. I don't think that I would attempt to use this with a repeater in lieu of a true duplexer (if that is your intent) as I'm not sure that you would get the necessary isolation between the transmitter and the receiver.
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 9:55 AM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2015 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions