Impex Transistors - UK Vintage Radio Repair and Restoration Discussion Forum

samoca58 · 5th Dec 2014, 3:29 pm

I have just obtained a Perdio Spinney that is a rebadged PR36 Fanfare (also available in Westminster , Challenge and EAR clones).

My question is: this Spinney has Impex transistors fitted in the first 3 mixer/osc IF positions. A label in the back advises that this model can have either Impex or Mullard (OC44/5) types fitted. If you do a google search for Impex transistors there is practically nothing.

How can a manufacturer of transistors from fifty years ago just vanish from history?

Can anybody point me in the direction of data sheets?

Herald1360 · 5th Dec 2014, 4:41 pm

Impex sounds suspiciously like a "brand" rather than a make.

Whatever they are, the characteristics for OC44/45 will be close enough.

vidjoman · 5th Dec 2014, 5:18 pm

I remember Impex Transistors - Can't remember what they were labled. We were given a quantity by an equipment manufacturer to build PCB's for them. Not sure where they came from but were metal cased and we had previously used Mullard OC44's on those boards.

Cobaltblue · 5th Dec 2014, 5:39 pm

A quick search and I found this at Pig Dog

Never seen this brand in the flesh as far as I remmember.

Cheers

Mike T

samoca58 · 5th Dec 2014, 5:40 pm

For the OC44 position the Impex is marked "Impex S44T" on the metal can and the OC45 positions are marked "Impex S45T" (one with orange spot the other a blue spot)

paulsherwin · 5th Dec 2014, 5:58 pm

'Impex' sounds suspiciously like an abbreviation of import-export so maybe they were sourced from Japan and remarked in the UK.

G6Tanuki · 5th Dec 2014, 5:59 pm

There exists a trail for a company "Philips Impex Limited" with a history going back to 1939.

Given the historical incestuous bond between Philips and Mullard, it doesn't take much to hypothesize that "IMPEX" was an IMPort-EXport division of the company?

[exit left thinking of James Bond and http://jamesbond.wikia.com/wiki/Universal_Exports ]

samoca58 · 5th Dec 2014, 6:02 pm

Import export - Interesting idea .

m0cemdave · 5th Dec 2014, 6:09 pm

I have an S31T and an S30T here, unused. They are in metal OC72 type cans. Interestingly, careful inspection reveals Mullard markings that have been mostly rubbed off, although I can't make out the original type numbers.

AC/HL · 5th Dec 2014, 11:41 pm

I've always understood Impex to be a Mullard/Philips brand, although why they needed another I don't know.

5th Dec 2014, 3:29 pm	#1
samoca58 Triode Join Date: Sep 2014 Location: Ringwood, Hampshire, UK. Posts: 29	Impex Transistors I have just obtained a Perdio Spinney that is a rebadged PR36 Fanfare (also available in Westminster , Challenge and EAR clones). My question is: this Spinney has Impex transistors fitted in the first 3 mixer/osc IF positions. A label in the back advises that this model can have either Impex or Mullard (OC44/5) types fitted. If you do a google search for Impex transistors there is practically nothing. How can a manufacturer of transistors from fifty years ago just vanish from history? Can anybody point me in the direction of data sheets?

5th Dec 2014, 4:41 pm	#2
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,652	Re: Impex Transistors Impex sounds suspiciously like a "brand" rather than a make. Whatever they are, the characteristics for OC44/45 will be close enough. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

5th Dec 2014, 5:18 pm	#3
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,698	Re: Impex Transistors I remember Impex Transistors - Can't remember what they were labled. We were given a quantity by an equipment manufacturer to build PCB's for them. Not sure where they came from but were metal cased and we had previously used Mullard OC44's on those boards.

5th Dec 2014, 5:39 pm	#4
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 7,793	Re: Impex Transistors A quick search and I found this at Pig Dog Never seen this brand in the flesh as far as I remmember. Cheers Mike T Attached Thumbnails __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

5th Dec 2014, 5:40 pm	#5
samoca58 Triode Join Date: Sep 2014 Location: Ringwood, Hampshire, UK. Posts: 29	Re: Impex Transistors For the OC44 position the Impex is marked "Impex S44T" on the metal can and the OC45 positions are marked "Impex S45T" (one with orange spot the other a blue spot)

5th Dec 2014, 5:58 pm	#6
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 30,593	Re: Impex Transistors 'Impex' sounds suspiciously like an abbreviation of import-export so maybe they were sourced from Japan and remarked in the UK.

5th Dec 2014, 5:59 pm	#7
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 15,908	Re: Impex Transistors There exists a trail for a company "Philips Impex Limited" with a history going back to 1939. Given the historical incestuous bond between Philips and Mullard, it doesn't take much to hypothesize that "IMPEX" was an IMPort-EXport division of the company? [exit left thinking of James Bond and http://jamesbond.wikia.com/wiki/Universal_Exports ]

5th Dec 2014, 6:02 pm	#8
samoca58 Triode Join Date: Sep 2014 Location: Ringwood, Hampshire, UK. Posts: 29	Re: Impex Transistors Import export - Interesting idea . Attached Thumbnails

5th Dec 2014, 6:09 pm	#9
m0cemdave Octode Join Date: Feb 2009 Location: Bletchley, Buckinghamshire, UK. Posts: 1,481	Re: Impex Transistors I have an S31T and an S30T here, unused. They are in metal OC72 type cans. Interestingly, careful inspection reveals Mullard markings that have been mostly rubbed off, although I can't make out the original type numbers.

5th Dec 2014, 11:41 pm	#10
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,651	Re: Impex Transistors I've always understood Impex to be a Mullard/Philips brand, although why they needed another I don't know.