UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Hints, Tips and Solutions (Do NOT post requests for help here)

Notices

Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

Closed Thread
 
Thread Tools
Old 27th Aug 2021, 3:41 pm   #1
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Green goo in coax

You're all aware of the green goo interaction between old PVC and copper..I saw it in coax for the first time today. I suspect that digital signals are more vulnerable to bad connections caused by this sort of thing, leading to blocking, dropouts, pixellation, nerve shattering digital screeches etc. Hopefully resolving this will solve the issues i've been trying to ignore for months- only permanent cure in this case though, is to rip out all the cable and replace. Oh Joy..
Dave
The Philpott is offline  
Old 27th Aug 2021, 4:30 pm   #2
Trevor
Octode
 
Join Date: Aug 2006
Location: Stoke-on-Trent, Staffordshire, UK.
Posts: 1,082
Default Re: Green goo in coax

while I was in the trade I was called to a faulty Rotel tuner on opening it up i could see that the input socket was corroded on checking the installation I noted that the coax feeder cable when opened up was full of water ! My conclusion an open connection box at the arial end had allowed rain water in .This along with the height difference created enough pressure for the rain water to enter the tuner and create the corrosion
Trev
Trevor is offline  
Old 27th Aug 2021, 5:20 pm   #3
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
Default Re: Green goo in coax

I've seen the green goo in some coax; it's usually caused by the plasticiser degrading and reacting with the copper. Added moisture helps the process along.

Black corrosion on the braid is another nof-unusual thing; again, water ingress is usually to blame.

In either case the coax is scrap.
G6Tanuki is offline  
Old 27th Aug 2021, 5:22 pm   #4
SiriusHardware
Dekatron
 
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,482
Default Re: Green goo in coax

I saw a Freesat receiver completely ruined in the same way, satellite coax makes a great drainpipe if the connection at the LNB is not waterproofed with self-amalgamating tape. I've seen some dish installations where the bare 'F' connector was just left to fend for itself.
SiriusHardware is online now  
Old 27th Aug 2021, 6:01 pm   #5
Guest
Guest
 
Posts: n/a
Default Re: Green goo in coax

A generous slavering of Vaseline also helps, and I mean generous to the point of very messy.
 
Old 27th Aug 2021, 9:27 pm   #6
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Green goo in coax

Post No.3- Rightly or wrongly, I associate 'black rot' with exposure to salty air. I've known it travel more than 12 inches up inside automotive wiring.
Dave
The Philpott is offline  
Old 27th Aug 2021, 11:24 pm   #7
Top Cap
Octode
 
Top Cap's Avatar
 
Join Date: Mar 2006
Location: Watford, Hertfordshire, UK.
Posts: 1,270
Default Re: Green goo in coax

Quote:
Originally Posted by Trevor View Post
while I was in the trade I was called to a faulty Rotel tuner on opening it up i could see that the input socket was corroded on checking the installation I noted that the coax feeder cable when opened up was full of water ! My conclusion an open connection box at the aerial end had allowed rain water in .This along with the height difference created enough pressure for the rain water to enter the tuner and create the corrosion
Trev
When in the trade many many many years ago, my boss and I went to fix a TV suffering from poor picture. The coax was full of water as could be seen by the water dripping from the aerial plug. When the customer asked how could that be, my boss said "You've been watching too much Thames Television" . It's appreciated youngsters may not get that joke.
__________________
Whether the Top Cap is Grid or Anode - touching it will give you a buzz either way!
Top Cap is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 5:07 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.