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.

Reply
 
Thread Tools
Old 23rd May 2024, 1:36 pm   #1
ScottBouch
Octode
 
ScottBouch's Avatar
 
Join Date: Feb 2013
Location: Leicestershire, UK.
Posts: 1,190
Default Plessey E3030 capacitors (red positive end)

Hi all,

Can anyone please shed some light on these Plessey E3030 capacitors? What type of capacitor are they?

The equipment is an early 1960's design, these may have been replaced before during service life, which may explain the different body colours, and numbers (date/batch codes perhaps).

They are suspect, part of a multivibrator circuit, that does not work. Other components are just two BJTs, and resistors. All will be checked, but the caps are the most obvious culprit to look at first.

Due to how they are fitted, I can only make out the first half of the numbers, will have to de-solder to attain the rest:
  • Plessey E3030-4262... (yellowy varnish looking colour)
  • Plessey E3030-78400.. (pale aluminium colour)

Can I tell the capacitance and voltage rating from the numbers? Does anyone have a catalogue?

I want to replace them, possibly with the more reliable Mullard Mustards, or failing that, something modern.

Cheers, Scott
Attached Thumbnails
Click image for larger version

Name:	plessey-e3030-1.jpg
Views:	109
Size:	77.1 KB
ID:	297916   Click image for larger version

Name:	plessey-e3030-2.jpg
Views:	91
Size:	55.6 KB
ID:	297917   Click image for larger version

Name:	plessey-e3030-3.jpg
Views:	70
Size:	58.1 KB
ID:	297918  
__________________
www.scottbouch.com
ScottBouch is offline   Reply With Quote
Old 23rd May 2024, 1:45 pm   #2
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,167
Default Re: Plessey E3030 capacitors (red positive end)

That sort of shiny red epoxy resin sealing to the positive end reminds me of the wet Tantalum electrolytic capacitors that are a regular nuisance in some Sixties and Seventies designed military gear.
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk.
G6Tanuki is online now   Reply With Quote
Old 23rd May 2024, 2:00 pm   #3
turretslug
Dekatron
 
turretslug's Avatar
 
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,423
Default Re: Plessey E3030 capacitors (red positive end)

I've seen very similar looking capacitors of that era from Hunts ("Huntalic") and STC ("Stantelum") - in both cases I think it reasonable to assume that the trade name implies a tantalum type.
turretslug is offline   Reply With Quote
Old 23rd May 2024, 2:08 pm   #4
ScottBouch
Octode
 
ScottBouch's Avatar
 
Join Date: Feb 2013
Location: Leicestershire, UK.
Posts: 1,190
Default Re: Plessey E3030 capacitors (red positive end)

Thanks guys, Tantalum wouldn't surprise me.

Could E3030 mean 30 V, 30 uF perhaps? (They are part of a 28 V DC powered system.)

Really need to understand the Plessey numbering system to identify a capacitance value for accurate replacement.

Cheers, Scott
__________________
www.scottbouch.com
ScottBouch is offline   Reply With Quote
Old 23rd May 2024, 2:15 pm   #5
ScottBouch
Octode
 
ScottBouch's Avatar
 
Join Date: Feb 2013
Location: Leicestershire, UK.
Posts: 1,190
Default Re: Plessey E3030 capacitors (red positive end)

PS: here is the circuit diagram, unfortunately there is no capacitance stated: https://www.scottbouch.com/mcfs/ligh...tivibrator.jpg

And the wider system it's part of: https://www.scottbouch.com/mcfs/ligh...ype-c.2780.htm

The multivibrator flashes some warning lamps. I am trying to find out the capacitance value in order to establish the time constant = flashing frequency.

Cheers, Scott
__________________
www.scottbouch.com
ScottBouch is offline   Reply With Quote
Old 23rd May 2024, 3:31 pm   #6
ScottBouch
Octode
 
ScottBouch's Avatar
 
Join Date: Feb 2013
Location: Leicestershire, UK.
Posts: 1,190
Default Re: Plessey E3030 capacitors (red positive end)

I have desoldered the capacitors now. They are now confirmed as marked:
  • Plessey E3030-62621 (yellowy varnish looking colour)
  • Plessey E3030-784001N (pale aluminium colour, looks like a newer one)

Maybe the numbers relate to 1962 and 1978?

My Fluke 87 DMM can only test small capacitances, so I'd need to rig something up to test these.

But my most pressing query is:
"What is their original capacitance value? Can we tell from decoding the numbers?"

Thanks, Scott
__________________
www.scottbouch.com
ScottBouch is offline   Reply With Quote
Old 24th May 2024, 8:43 am   #7
ScottBouch
Octode
 
ScottBouch's Avatar
 
Join Date: Feb 2013
Location: Leicestershire, UK.
Posts: 1,190
Default Re: Plessey E3030 capacitors (red positive end)

I tested these last night with a square wave, charge/discharge via resistors, and scope. They both appeared to work fine! Same wavform from both, and from this I estimated their value to be approximately 30uF, which also coincides with my assumption theory about the part number.

With the resitors in circuit, this gives a multivibrator frequency of about 2.4Hz, which sounds about right, I now need to verify this against old videos showing these lamps flashing. This video I took shows the lamps flashing, but the condition of the capacitors is unknown in this instance, so lamp frequency may be correct, or may be treated with a pinch of salt: https://scottbouch.com/English-Elect...on-getters.mp4

But the multivibrator I have is still not functioning, I have checked all resistors, these are OK, so the next suspect parts to be checked will be the GET110 and GET111 transistors.

Cheers, Scott
__________________
www.scottbouch.com

Last edited by ScottBouch; 24th May 2024 at 8:51 am.
ScottBouch is offline   Reply With Quote
Old 24th May 2024, 4:39 pm   #8
ScottBouch
Octode
 
ScottBouch's Avatar
 
Join Date: Feb 2013
Location: Leicestershire, UK.
Posts: 1,190
Default Re: Plessey E3030 capacitors (red positive end)

Fixed it! I found a bad earth connection, turns out the multivibrator was fine all along! It now works well with all original parts!

Video showing end result here under the heading of "Experiment No.1:" https://www.scottbouch.com/mcfs/ligh...unit-d8700.htm

Cheers, Scott.
__________________
www.scottbouch.com
ScottBouch is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 8:21 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.