receive no transmit - Page 2 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #11  
Old 07-02-2008
Senior Member
 
Join Date: Jun 2007
Posts: 2,708
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
SEMIJim will become famous soon enough SEMIJim will become famous soon enough
Quote:
Originally Posted by jdair101 View Post
Ok== today I picked up an emergency antenna and guess what-- I can both receive and transmit.
That narrows it down a bit .

Quote:
Originally Posted by jdair101 View Post
Before I made the purchace I checked the wiring from the radio to the base of the mast and it was ok.
Define "checked the wiring."

Quote:
Originally Posted by jdair101 View Post
Next I checked for resistance at the base of the mast and it was open.
Did you read that article to which I pointed you earlier? Under "Testing":
Quote:
Simple Test. It may be possible to perform a simple test on the antenna after you have installed the connector by measuring the DC resistance between the connector's center pin and outer shield (obvously, the radio must be disconnected from the antenna to do this). Oddly enough, you may measure either an open (high resistance) or a short (low resistance). This characteristic is dependant on the antenna's design,...
Quote:
Originally Posted by jdair101 View Post
So I guess up the mast I go.
Indeed. But you'd be well-served by reading that article, first, so you have a better idea of what you're doing.

Simple test of coax:
  1. Disconnect from radio and antenna
  2. Check at either end for open between center-conductor and shield
  3. Short center-conductor to shield at either end (doing this well is harder than it seems)
  4. Check for near-zero ohms resistance at other end (getting the meter probes electrically firmly on both center-conductor and shield is harder than it looks)
You can check the antenna for it's characteristic DC resistance, assuming it's not (already) broken, by putting the meter across the center-conductor and shield before connecting the coax, too. It will measure either open, or extremely close to zero. Knowing which of those it should be is important, of course.

But: DC resistance tests on antenna systems are a crude check, at best. Assuming they check out, DC-wise, you really need to put an SWR bridge on the system, as well.

Then, if/when that all checks out: You need to test it in real life with some test communications.

Good Luck.

Jim

Last edited by SEMIJim; 07-02-2008 at 09:01 AM.
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
VHF Radio won't transmit scurvy Gear & Maintenance 19 07-14-2007 08:45 PM
Eye-splicing lines... beatkiddo Seamanship & Navigation 11 09-20-2006 02:28 PM
Superfluous Sextant? akoutdoors1 Seamanship & Navigation 4 08-10-2006 11:51 AM
What''s the best way to receive mail? prussell Cruising & Liveaboard Forum 5 04-02-2003 09:22 AM
High-Frequency Radio Basics Kathy Barron Her Sailnet Articles 0 10-14-2000 09:00 PM


All times are GMT -4. The time now is 10:21 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.