RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Topic Specific Forums > Antennas and Associated Hardware > Coax Cable and Connectors

Coax Cable and Connectors For general discussion of all things pertaining to coax cable, wave guide or any other medium for passing RF energy. This includes connectors, weather proofing and grounding.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 10-17-2011, 11:14 AM
dcorby's Avatar
Member
   
Join Date: Jul 2005
Location: Colden, NY
Posts: 5
Question Splitter with cables

I am putting up a new Diamond Discone antenna with a 16 port powered splitter (Multi-Coupler) from Digital Loggers. The antenna run is LMR-400 with Type N Connectors. The length is 100' total. From the multicoupler I am trying to decide what cable to run. Each cable from the Multi-Coupler is less than 30 feet. They will need BNC connectors on each. I was debating on using RG6 Quad Shielded. Will the losses be too great? I am running multiple scanners throughout my house, and monitor frequencies from 37 Mhz up to 800 Mhz. Thanks!
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 10-19-2011, 7:21 PM
R1VINCE's Avatar
Member
   
Join Date: Mar 2008
Location: Fairfield, Ca.
Posts: 412
Default

I have the exact same setup as you.

I acquired a partially used roll of RG6-Quad shield and bought my connectors via ebay and made my own various length pigtails going to different parts of my office. Also, I would suggest different colored heat shrink to color code your connectors on both ends for easier reference.

The connectors that I got are the "twist" on style.
Attached Images
 
__________________
My Youtube page
Reply With Quote
  #3 (permalink)  
Old 10-23-2011, 8:33 PM
mpddigital's Avatar
Member
   
Join Date: Jul 2010
Location: SW GA - 30 years South of Atlanta
Posts: 102
Default

What you are doing will work. The LMR-400 run to the antenna will not match with the 75 ohm rg-6 but the mismatch will not cause much additional loss in scanner use.
Reply With Quote
  #4 (permalink)  
Old 10-24-2011, 1:48 AM
n5ims's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2004
Posts: 2,911
Default

Quote:
Originally Posted by R1VINCE View Post
I have the exact same setup as you.

I acquired a partially used roll of RG6-Quad shield and bought my connectors via ebay and made my own various length pigtails going to different parts of my office. Also, I would suggest different colored heat shrink to color code your connectors on both ends for easier reference.

The connectors that I got are the "twist" on style.
That's a nice looking setup, but I would suggest a few changes. You can get some BNC connectors for RG-6 that are very easy to install and work much better than the twist on ones. These connectors (FS6BNCU compression connector for RG6 or the right angle version FSBNC6URA compression connector for RG6) use the standard compression tools used for the standard Cable-TV F connectors. They're commonly used for CCTV or home theater installs, but work great for BNC scanners. The ones I linked to are simply to show you what's available so Google "BNC Compression Connector" to help find the best price, etc.

Also instead of simply color coding the cables, get one of the label makers and some clear shrinkable tubing. That way instead of remembering that the short yellow with long pink is the living room you can simply read the label (the clear tubing is simply to protect the label from dirt and prevent it from working loose/falling off).
Reply With Quote
  #5 (permalink)  
Old 10-25-2011, 9:37 PM
R1VINCE's Avatar
Member
   
Join Date: Mar 2008
Location: Fairfield, Ca.
Posts: 412
Default

Quote:
Originally Posted by n5ims View Post
That's a nice looking setup, but I would suggest a few changes. You can get some BNC connectors for RG-6 that are very easy to install and work much better than the twist on ones. These connectors (FS6BNCU compression connector for RG6 or the right angle version FSBNC6URA compression connector for RG6) use the standard compression tools used for the standard Cable-TV F connectors. They're commonly used for CCTV or home theater installs, but work great for BNC scanners. The ones I linked to are simply to show you what's available so Google "BNC Compression Connector" to help find the best price, etc.

Also instead of simply color coding the cables, get one of the label makers and some clear shrinkable tubing. That way instead of remembering that the short yellow with long pink is the living room you can simply read the label (the clear tubing is simply to protect the label from dirt and prevent it from working loose/falling off).

My setup was actually like that some time ago. Im not saying in anyway that your suggestions are not good. They are in fact what I had initially done to get my radios set up. I changed from that setup to what you currently see in the above pic. I changed for a few reasons:

1. I actually have a Brother label maker that I used to label all pigtail ends with. It worked fine, but I found myself picking the wrong one anyway when assembling my radio hutch together because all the labels were "white" in color and all looked the same anyway when reaching from behind a shelf to connect. All pigtails come from the same place, but not all are the same length. So switching them back and forth was trial and error in some cases. I found the colors to be a lot more beneficial in quicker identificationI(although I dont seem to be back there all the time anyway).


2. I couldnt find crimp style connectors with the center dielectric foam surround that I wanted to have.
I used to use crimp style connectors on all my connections. But I didnt have enough when I switched from 8way to 16way. So i used an extra pair of these twist-ons. I noticed a small but significant difference in the amount of noise and lack of spurious signals coming in on a particular radio. That one radio had the only assembled pigtail with the twist-on BNC's.When I switched the cable to the crimp-on the noise and spurious activity was back. I moved the twist-on set to another radio, and the same results. My squelch settings got tighter and the spurious activity decreased. Same RG-6/Quad from the same spool, just different connectors. I dont exactly know the science behind it, but I switched all my connectors over to the twist-ons and experienced much better results on all my receivers. Im guessing that that missing center dielectric foam in the middle has something to do with it.
I had a hard time trying to find crimp-ons with the center foam for RG-6/Quad. There are a few out there, but were expensive or I had to buy in huge bulk, and/or it took 6-8 weeks delivery from overseas.


This pic shows the Twist-on BNC on the left and the Crimp-on style BNC on the right.
Im sure you can all see the difference - I can hear it!
Attached Images
 
__________________
My Youtube page
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 10-25-2011, 10:37 PM
jfhtm350's Avatar
Member
   
Join Date: Dec 2010
Location: New Market TN
Posts: 839
Default

Quote:
Originally Posted by R1VINCE View Post
This pic shows the Twist-on BNC on the left and the Crimp-on style BNC on the right.
Im sure you can all see the difference - I can hear it!
To me it looks like the white insulator is supposed to be there, just missing. Why would they make connectors without the insulator like that? You are right not to want the connector without the insulator.
Reply With Quote
  #7 (permalink)  
Old 10-25-2011, 10:49 PM
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jun 2006
Posts: 3,444
Default

BNC connectors without the dielectric insulation around the pin are usually 75 ohm versions.
prcguy

Quote:
Originally Posted by jfhtm350 View Post
To me it looks like the white insulator is supposed to be there, just missing. Why would they make connectors without the insulator like that? You are right not to want the connector without the insulator.
Reply With Quote
  #8 (permalink)  
Old 10-25-2011, 11:10 PM
jfhtm350's Avatar
Member
   
Join Date: Dec 2010
Location: New Market TN
Posts: 839
Default

Well let me ask you this if you know. If one of those connectors is a 50ohm and the other is a 75ohm, what is the difference besides the insulator? Is one made for a bigger wire or something? There should not be a difference in resistance if you measure them both with a multimeter in my way of thinking. Couldnt you use a 75ohm connector on a 50ohm cable and vice versa and it still be the same thing is basically what im asking.
Reply With Quote
  #9 (permalink)  
Old 10-25-2011, 11:14 PM
jfhtm350's Avatar
Member
   
Join Date: Dec 2010
Location: New Market TN
Posts: 839
Default

I see a difference on the outer rim of the connector at the base. One has rounded semi holes cut out and the other has squared semi holes cut out. I guess that must be so that it fits the correct ohm bnc connector, right? But other than that couldnt you use either one?
Reply With Quote
Sponsored links
  #10 (permalink)  
Old 10-25-2011, 11:27 PM
gmclam's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Sep 2006
Location: Fair Oaks, CA
Posts: 4,898
Smile Your setup sounds good

Quote:
Originally Posted by dcorby View Post
I am putting up a new Diamond Discone antenna with a 16 port powered splitter (Multi-Coupler) from Digital Loggers. The antenna run is LMR-400 with Type N Connectors. The length is 100' total.
I am running a discone with about 50' of Air-802 coax (sold as LMR-400 compatible) to my splitting station. First I run through high pass and band notch filters before an 8 way multicoupler. I use BNC or N connectors made for the coax with no adapters. I feel this portion of the run is most important since it is unamplified and feeding an amp. The notch filters remove FM broadcast, the strongest signals from the antenna.

Quote:
From the multicoupler I am trying to decide what cable to run. Each cable from the Multi-Coupler is less than 30 feet. They will need BNC connectors on each. I was debating on using RG6 Quad Shielded. Will the losses be too great? I am running multiple scanners throughout my house, and monitor frequencies from 37 Mhz up to 800 Mhz.
That is what I am doing as well -- RG6 quad low loss with BNCs on both ends. My shortest run is 10' and the longest is 70' from the multicoupler. My listening is from 42MHz (CHP) to 860MHz (state parks).

The thing here is that all RG6 (or any type) of coax is not created equal. There is some awful stuff out there, but there is some great stuff too. The loss on the RG6 I am using is less than the loss of many types of RG8 or RG11 at 800MHz. Plus there are several practical issues to deal with such as trying to connect a very rigid coax (LMR-400) directly to a radio. Also, do not forget to terminate all non-connected coaxes. Each output of the multi-coupler should see a 50 ohm load.
__________________
PRO-95 | PRO-10 | PRO-97 | PRO-77 | PRO-92 | PSR-300 | PSR-310

Last edited by gmclam; 10-25-2011 at 11:30 PM..
Reply With Quote
Reply

Tags
cable, multi output, type

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 1:37 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2011 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions