Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 29-09-2018, 15:41   #1
Registered User

Join Date: Jun 2018
Posts: 29
Need help identifying antenna connector and advice going forward

Photo album: https://imgur.com/a/CHX40Lg

Helping a friend with a project boat. He's getting ready to close the coach (house?) deck so I have to run the wires that are concealed there. The original builder ran the VHF antenna cable under the headliner to the point pictured, where there is a tight radius needed to bend the wires through the deck before entering the deck-stepped mast. Not sure if this is best but it's how it was done.

The whip antenna has a connector much smaller than a PL259. The cable is labeled Network Lab Inc and is RG58C/U.

Thinking of replacing with 213 cable, Metz whip, and 259 connectors. Worried about the radius. Comments?
__________________

chollapete is offline   Reply With Quote
Old 29-09-2018, 16:07   #2
Registered User
 
S/V Illusion's Avatar

Join Date: Oct 2007
Location: Lakewood Ranch, FLORIDA
Boat: Alden 50, Sarasota, Florida
Posts: 1,891
Re: Need help identifying antenna connector and advice going forward

Difficult to provide a reliable answer as we have no clue what you refer to as a "tight radius". It's possible to compromise the dielectric spacing with RG213 depending on how "tight" the turn is but if you are worried about it, use LMR 200 or equivalent and check the bending specs on the cable manufacturer's web site.
__________________

S/V Illusion is offline   Reply With Quote
Old 30-09-2018, 06:07   #3
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 33,653
Images: 240
Re: Need help identifying antenna connector and advice going forward

PL259 connectors come in a 90 Deg version. Perhaps yours do, as well.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 30-09-2018, 06:11   #4
Registered User

Join Date: Aug 2013
Location: Laboe - Germany
Posts: 536
Re: Need help identifying antenna connector and advice going forward

Quote:
Thinking of replacing with 213 cable, .... Worried about the radius. Comments?
Most (if not all) RG-213 cables are specified to need 10cm (4") radius (for a 'one-time bend'), around 15cm if bended more than once.

Regards,

Carsten
CarstenWL is offline   Reply With Quote
Old 30-09-2018, 07:37   #5
Registered User

Join Date: Jun 2018
Posts: 29
Re: Need help identifying antenna connector and advice going forward

@Carsten: Thanks. I had also found 5x cable diameter as a rough guide for coax. I think I'll be going with RG-8X, as I believe it is stranded and somewhere I saw it specec'ed for 1/2 inch bends--but 1-1/4 inch will be sufficient.

Could you or anyone else identify the antenna socket? I found reference to a "mini-UHF" plug. Again, this is an unlabeled antenna, but if it came as a kit with the cable, it would be Network Lab Inc., which has a website.

My friend's budget seems tight, so I'd rather keep the existing whip and find the correct connector. This isn't my area of knowledge.

PS. On second thought, I'll just order a mini-UHF connector and see if it fits. They're easy to find online. Sorry to seem so needy. Lol.
chollapete is offline   Reply With Quote
Old 30-09-2018, 08:39   #6
Registered User

Join Date: Aug 2013
Location: Laboe - Germany
Posts: 536
Re: Need help identifying antenna connector and advice going forward

@collapete:

RG8X or any cable with a tinned / silvered outer jacket would be my preference too.

Can you post a picture "how the connection looks inside the antenna"?
Could it be a FME connector? (https://tinyurl.com/y8h6mlcl)

Regards,

Carsten
CarstenWL is offline   Reply With Quote
Old 30-09-2018, 08:49   #7
Registered User
 
Nicholson58's Avatar

Join Date: Jan 2011
Location: Caribbean live aboard
Boat: Camper & Nicholson58 Ketch - ROXY Traverse City, Michigan No.668283
Posts: 4,046
Images: 83
Re: Need help identifying antenna connector and advice going forward

You should use the low impedance cable, particularly for a long run.
Nicholson58 is offline   Reply With Quote
Old 30-09-2018, 08:53   #8
Registered User

Join Date: Aug 2013
Location: Laboe - Germany
Posts: 536
Re: Need help identifying antenna connector and advice going forward

Quote:
You should use the low impedance cable, particularly for a long run.
You should use 52 Ohm impedance cable (might qualify as low impedance ;-)) ...
You should use low loss cable, especially for a long run ...

:-)

Carsten
CarstenWL is offline   Reply With Quote
Old 30-09-2018, 09:20   #9
Registered User
 
Nicholson58's Avatar

Join Date: Jan 2011
Location: Caribbean live aboard
Boat: Camper & Nicholson58 Ketch - ROXY Traverse City, Michigan No.668283
Posts: 4,046
Images: 83
Re: Need help identifying antenna connector and advice going forward

Quote:
Originally Posted by CarstenWL View Post
You should use 52 Ohm impedance cable (might qualify as low impedance ;-)) ...
You should use low loss cable, especially for a long run ...

:-)

Carsten
Yes.

AIS especially suffers on high impedance cable.
Nicholson58 is offline   Reply With Quote
Old 30-09-2018, 09:48   #10
Registered User

Join Date: Jun 2018
Posts: 29
Re: Need help identifying antenna connector and advice going forward

Quote:
Originally Posted by Nicholson58 View Post
You should use the low impedance cable, particularly for a long run.
Thanks. I know. I'd prefer RG-213, but do to cost and bending radius I'm leaning toward Ancor RG-8X.

The run is about 55 feet, so a table at West Marine shows attenuation at 60 feet for RG-213 at -1.6dB and RG-8X at -2.7dB. I don't entirely understand decibel math, but exp(-1.6) ~ 0.2 while exp(-2.7) ~ 0.07.

He had been running (and was happy with) old RG-58CU with attenuation of -3.6dB ~ exp(-3.6) ~ 0.03. Not sure how to convert all this into percentages.

Also, it may have been that he could hear others clearly, but others heard garble when *he* transmitted.
chollapete is offline   Reply With Quote
Old 30-09-2018, 09:53   #11
Registered User

Join Date: Jul 2018
Posts: 83
Re: Need help identifying antenna connector and advice going forward

Quote:
Originally Posted by chollapete View Post
Thanks. I know. I'd prefer RG-213, but do to cost and bending radius I'm leaning toward Ancor RG-8X.

...
If you need a tigher turn radius then LMR400 has a 1 inch turn radius.
RG8x has about twice the loss over lrm400 or rg213. Avoid id it you can.
__________________
Gary
ohgary is offline   Reply With Quote
Old 30-09-2018, 11:39   #12
Registered User

Join Date: Jan 2010
Location: St Michaels, MD
Boat: Cal 46-3, 46' ketch
Posts: 217
Re: Need help identifying antenna connector and advice going forward

Spent my career in telecommunications working with coax of all sizes/ types and a ham and sailer for 40+ yrs... if you use right angle RG-259/8 adapters make sure you tighten with plyers, paint with liquid tape, and use ‘outdoor/ weather resistant heat shrink material (has sticky goo inside). This is especially true when such adapters are going into inaccessible areas in marine environments. If at all possible, avoid the hidden adapters and adhere to the recommended coax radius spec. Consider that coax installation a ‘safety of life’ install where someone’s life may depend on choices made & workmanship.
W3GAC is offline   Reply With Quote
Old 30-09-2018, 11:48   #13
Registered User

Join Date: Sep 2017
Location: Langley, WA
Boat: Nordic 44
Posts: 520
Re: Need help identifying antenna connector and advice going forward

Quote:
Originally Posted by ohgary View Post
If you need a tigher turn radius then LMR400 has a 1 inch turn radius.
RG8x has about twice the loss over lrm400 or rg213. Avoid id it you can.
LMR400 is a foam dielectric and has a bend radius far greater than one inch. It also has a solid, copper plated aluminum center conductor that will cut through the foam core and short to the shield if bent too tight.

RG213 has a stranded copper core and a solid core that is far more resistant to shorting when bent. There is marine grade RG213 cable available that is tinned.

The DB signal loss translates to a reduction of signal strength of 50% for every 3 db. IOW a three db loss means that half the signal strength received at the antenna is lost.
stormalong is offline   Reply With Quote
Old 30-09-2018, 11:52   #14
Registered User

Join Date: Jan 2016
Location: San Diego, CA
Boat: Beneteau 40.7
Posts: 155
Re: Need help identifying antenna connector and advice going forward

PL-259 connectors do not have have a controlled impedance which means they can be somewhat inconsistent in their loss characteristics. At typical marine frequencies this is not a big problem. I would prefer TNC connectors in critical applications. Probably the best cable for this application is Times Microwave LMR-400. It has a solid center conductor so it is not suitable for frequent flex applications but it has the lowest loss in its class.

Do not use right angle connectors or adapters because of their loss issues except for "swept" (curved) components.

Probably more important than all this is to ensure all exposed connections are weathertight on a long term basis. I like heat shrink sleeving with a flexible adhesive inside or an overall coat of silicone adhesive.
thunderhoof is offline   Reply With Quote
Old 30-09-2018, 11:57   #15
Registered User
 
Cadence's Avatar

Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 7,645
Re: Need help identifying antenna connector and advice going forward

Quote:
Originally Posted by GordMay View Post
PL259 connectors come in a 90 Deg version. Perhaps yours do, as well.
That would be my solution. Placing an abrupt turn in coax probably wouldn't help a match.
__________________

Cadence is offline   Reply With Quote
Reply

Tags
antenna

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need help identifying a sail and a question. bermudabob General Sailing Forum 1 23-05-2015 16:06
Need Help Identifying Westerbeke Block phorvati Engines and Propulsion Systems 8 23-11-2011 13:09
Need Help Identifying this Dinghy . . . MarkRoadley General Sailing Forum 7 25-09-2011 08:15
Need Help Identifying a Yacht DDabs Monohull Sailboats 3 18-08-2011 13:00
Need Help Identifying this Boat joblob Powered Boats 8 26-04-2011 22:27



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:47.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.