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 > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Closed Thread
 
Thread Tools
Old 9th Dec 2008, 9:32 pm   #1
Racalfanatic
Pentode
 
Racalfanatic's Avatar
 
Join Date: Aug 2007
Location: Stoke-on-Trent, Staffordshire, UK.
Posts: 105
Default Tin Whiskers in an OC171. AF114, AF117 etc..

Hi All,
I removed three faulty OC171 transistors from my Eddystone EC10 Receiver.
I removed the base and the following photos are what I saw:


http://img.photobucket.com/albums/v2.../OC171/tw2.jpg
http://img.photobucket.com/albums/v2.../OC171/tw3.jpg
http://img.photobucket.com/albums/v2.../OC171/tw5.jpg
__________________
Cheers,

Ian G1DRP

Last edited by Racalfanatic; 9th Dec 2008 at 10:01 pm.
Racalfanatic is offline  
Old 9th Dec 2008, 11:09 pm   #2
mark pirate
Dekatron
 
mark pirate's Avatar
 
Join Date: Mar 2008
Location: Worthing, West Sussex, UK
Posts: 5,147
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Excellent photos . If you search the forums you will find a very interesting thread on this very subject.

Paul Stenning sent some AF11x transistors to NASA for disection, fascinating thread.

Mark

Last edited by Darren-UK; 9th Dec 2008 at 11:13 pm. Reason: FSK problem fixed.
mark pirate is offline  
Old 9th Dec 2008, 11:45 pm   #3
Colin
Heptode
 
Colin's Avatar
 
Join Date: Jun 2004
Location: Ilkley, West Yorkshire, UK.
Posts: 656
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Wonderful pics ... how did you take them?
__________________
Colin Armstrong
Colin is offline  
Old 10th Dec 2008, 12:46 pm   #4
kalee20
Dekatron
 
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 6,423
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Brilliant photos, congratulations!

What always beats me about this, is why Mullard et al used a tin plated metal can? Tin whiskering wasn't a new phenomenon in the 1960's, even though it was not well understood!
kalee20 is offline  
Old 13th Dec 2008, 11:58 am   #5
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 19,601
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Perhaps they thought that the equipment these transistors were installed in would be thrown away after a few years. They wouldn't have expected people to be repairing such sets nearly 50 years later.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 13th Dec 2008, 12:17 pm   #6
Steve_P
Dekatron
 
Steve_P's Avatar
 
Join Date: Sep 2003
Location: Bolton, Greater Manchester, UK.
Posts: 6,634
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Maybe not here, but NASA are involved in research on this because of (and this would be a great idea for a sci-fi film)....

AF117's in space.

Cheers,

Steve P.
__________________
If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?
Steve_P is offline  
Old 13th Dec 2008, 3:01 pm   #7
Geoff 555
Heptode
 
Geoff 555's Avatar
 
Join Date: Jan 2008
Location: Bristol, UK.
Posts: 979
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

UMM I wonder what they used in HAL?

Cheers.
Geoff.
Geoff 555 is offline  
Old 13th Dec 2008, 3:43 pm   #8
ukcol
Rest in Peace
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

This would be the thread that Mark was refering to.

https://www.vintage-radio.net/forum/...light=whiskers
ukcol is offline  
Old 13th Dec 2008, 5:27 pm   #9
Steve_P
Dekatron
 
Steve_P's Avatar
 
Join Date: Sep 2003
Location: Bolton, Greater Manchester, UK.
Posts: 6,634
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Geoff - They probably used AF117's. Why it wen't strange....

Cheers,

Steve P.
__________________
If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?
Steve_P is offline  
Old 14th Dec 2008, 12:31 am   #10
JHGibson
Hexode
 
Join Date: Apr 2003
Location: Salt Spring Island, BC, Canada
Posts: 368
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

VK3JEG had a problem with a whiskered OC171 in his EC10 and replaced it with a modern silicon transistor. For his notes, go to www.qsl.net/vk3jeg/edd_ec10.html
John.
JHGibson is offline  
Old 15th Dec 2008, 10:01 pm   #11
Racalfanatic
Pentode
 
Racalfanatic's Avatar
 
Join Date: Aug 2007
Location: Stoke-on-Trent, Staffordshire, UK.
Posts: 105
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Quote:
Originally Posted by Colin View Post
Wonderful pics ... how did you take them?
Hi Colin,
I used a simple compact camera in macro mode, aperture priority with the aperture stopped right down, spot metering and a halogen reading lamp!
__________________
Cheers,

Ian G1DRP
Racalfanatic is offline  
Old 15th Dec 2008, 10:33 pm   #12
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 24,894
Default Re: Tin Whiskers in an OC171. AF114, AF117 etc..

Quote:
Originally Posted by Racalfanatic View Post
I used a simple compact camera in macro mode, aperture priority with the aperture stopped right down, spot metering and a halogen reading lamp!
It shows what excellent pictures can be taken with quite modest equipment these days.

No more discussion of cameras in this thread please folks, it's OT for the forum.

Paul
paulsherwin is offline  
Closed Thread

Thread Tools



All times are GMT. The time now is 10:37 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 - 2022, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.