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 > General Vintage Technology Discussions

Notices

General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc.

Closed Thread
 
Thread Tools
Old 16th Mar 2014, 9:53 pm   #181
AC/HL
Dekatron
 
AC/HL's Avatar
 
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
Default Re: Forgotten Knowledge

Anybody have any Vintage Radioey type reminiscences to squeeze a bit of relevance back into this thread before the inevitable?
AC/HL is offline  
Old 16th Mar 2014, 10:38 pm   #182
G8HQP Dave
Rest in Peace
 
Join Date: Sep 2008
Location: Solihull, West Midlands, UK.
Posts: 4,872
Default Re: Forgotten Knowledge

I suspect a generic skill which may be disappearing is the ability to knock up (from whatever is available to hand) a cheap approximation to whatever test equipment is needed but lacking for a debugging or faultfinding session. For example, measuring inductance without an L meter.
G8HQP Dave is offline  
Old 16th Mar 2014, 10:58 pm   #183
Biggles
Rest in Peace
 
Join Date: Feb 2004
Location: Hexham, Northumberland, UK.
Posts: 2,234
Default Re: Forgotten Knowledge

Before the advent of remote controls, having to actually get up to change the TV to one of the other two channels which were available, then twiddling the fine tune on the turret tuner for the best picture with least video on sound?
Biggles is offline  
Old 17th Mar 2014, 12:06 am   #184
G0HZU_JMR
Dekatron
 
Join Date: Sep 2010
Location: Cheltenham, Gloucestershire, UK.
Posts: 3,077
Default Re: Forgotten Knowledge

Quote:
Originally Posted by G8HQP Dave View Post
I suspect a generic skill which may be disappearing is the ability to knock up (from whatever is available to hand) a cheap approximation to whatever test equipment is needed but lacking for a debugging or faultfinding session. For example, measuring inductance without an L meter.
I've tried to explain to people on other forums how easy it is the measure the capacitance and ESR vs frequency for an electrolytic cap by just using a dual channel scope + a sig gen and a sense resistor (and some basic trig/vector maths in an excel spreadsheet)

You can quickly measure ESR and capacitance across several frequencies and also spot where the cap is series resonant.

The cost is nothing if they already have the scope and sig gen.

But the above method isn't as 'cool' as having something from ebay with a digital display even if it means the thing with the digital display is less versatile, less accurate, gives less information over a limited frequency range and is far more expensive.
__________________
Regards, Jeremy G0HZU
G0HZU_JMR is offline  
Old 17th Mar 2014, 2:40 am   #185
fetteler
Octode
 
fetteler's Avatar
 
Join Date: Jul 2011
Location: Staffordshire Moorlands, UK.
Posts: 1,464
Default Re: Forgotten Knowledge

Quote:
Originally Posted by G0HZU_JMR View Post
I've tried to explain to people on other forums how easy it is the measure the capacitance and ESR vs frequency for an electrolytic cap by just using a dual channel scope + a sig gen and a sense resistor (and some basic trig/vector maths in an excel spreadsheet)
You can quickly measure ESR and capacitance across several frequencies and also spot where the cap is series resonant.
There's huge gaps in my knowledge and I'd love to know how to do this!! Please explain to me here

Steve.
__________________
Those who lack imagination cannot imagine what is lacking...
fetteler is offline  
Old 17th Mar 2014, 9:35 am   #186
broadgage
Nonode
 
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
Default Re: Forgotten Knowledge

Remembering when an inverter was not solid state but consisted of a DC motor driving an alternator, the really clever ones used a thermionic valve to adjust the alternator field and thereby regulate the output voltage.

Carbon filament lamps, and knowing the handful of applications for which these were better than metal filament lamps.

Use of a basic and home made forge for basic blacksmithing work. An old vaccuum cleaner makes a good blower, speed adjusted by lamps of varying number and wattage in series with it.

Use of 240 volt GLS lamps on 415 volts so as to give an extremely bright light for cine filming. They only lasted an hour or so but were much cheaper than the purpose made "photoflood" lamps that only lasted a few hours anyway.
broadgage is offline  
Old 17th Mar 2014, 10:16 am   #187
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,801
Default Re: Forgotten Knowledge

Knowing that the red terminal went negative when you selected the ohms range

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline  
Old 17th Mar 2014, 12:43 pm   #188
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
Default Re: Forgotten Knowledge

I think we've let this thread ramble on for long enough now, and it's time to call a halt.
paulsherwin is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 8:54 am.


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.