Cossor CDU 150 Semiconductor Cross Reference List - UK Vintage Radio Repair and Restoration Discussion Forum

Chris55000 · 22nd May 2020, 11:21 am

Hi!

There were two Manuals issued by Cossor for the CDU150/CT531 oscilloscope, I can confirm that Issue 1 dated does indeed give only Cossor Part Numbers for the semiconductor devices used with no further detail on the circuits themselves! Fortunately, Issue 2 which I obtained by online purchase does contain full semiconductor details, so I'll put the two together and provide a cross–reference list for each panel/assembly in alphabetical order from Panel A to J2, followed by the chassis assembly at the end.

Chris Williams

MelJon66 · 22nd May 2020, 12:17 pm

Hi Chris,

I have Issue 2 of the manual which you made available via your Dropbox earlier this year. It does indeed have semiconductor details but some of them appear to be military types that are hard to find even if you do have the manufacturer's part numbers.

Fairchild U17718's are used on PCB H1. These are double transistors and two are used on each channel. The only thing I could find was that Ellison Electronics say they stock them in the UK. I don't need them yet but it would be fantastic if you could find and list suitable substitutes for those

.

Cheers
Mel

Chris55000 · 22nd May 2020, 1:39 pm

Hi!

Dual TO–78 transistors have a habit of being expensive, but I can suggest an excellent matched pair in TO–78 cans currently available from RS, Mouser, etc., this is the Analog Devices MAT01GHZ, rated 45V at 25mA, hFE 400–500, fT 450 MHz, currently priced about £14 each from RS.

https://www.google.com/url?sa=t&sour...AiqWGex3fnc8AR

Looking at the datasheet, I'd be very surprised if any modern oscilloscope amplifier objected to these!

Chris Williams

I can still supply more CDU150 parts, including the dual transistors, if you have a blow–up emergency!

MelJon66 · 22nd May 2020, 3:12 pm

Hi Chris,

Great information but they are a bit pricey to have just in case aren't they. If they blow I might take you up on your offer.

I do need something for the Cossor now so I will PM you.

Cheers
Mel

22nd May 2020, 11:21 am	#1
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,874	Cossor CDU 150 Semiconductor Cross Reference List Hi! There were two Manuals issued by Cossor for the CDU150/CT531 oscilloscope, I can confirm that Issue 1 dated does indeed give only Cossor Part Numbers for the semiconductor devices used with no further detail on the circuits themselves! Fortunately, Issue 2 which I obtained by online purchase does contain full semiconductor details, so I'll put the two together and provide a cross–reference list for each panel/assembly in alphabetical order from Panel A to J2, followed by the chassis assembly at the end. Chris Williams __________________ It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed!

22nd May 2020, 12:17 pm	#2
MelJon66 Pentode Join Date: Apr 2020 Location: Somerset, UK. Posts: 174	Re: Cossor CDU 150 Semiconductor Cross Reference List Hi Chris, I have Issue 2 of the manual which you made available via your Dropbox earlier this year. It does indeed have semiconductor details but some of them appear to be military types that are hard to find even if you do have the manufacturer's part numbers. Fairchild U17718's are used on PCB H1. These are double transistors and two are used on each channel. The only thing I could find was that Ellison Electronics say they stock them in the UK. I don't need them yet but it would be fantastic if you could find and list suitable substitutes for those . Cheers Mel

22nd May 2020, 1:39 pm	#3
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,874	Re: Cossor CDU 150 Semiconductor Cross Reference List Hi! Dual TO–78 transistors have a habit of being expensive, but I can suggest an excellent matched pair in TO–78 cans currently available from RS, Mouser, etc., this is the Analog Devices MAT01GHZ, rated 45V at 25mA, hFE 400–500, fT 450 MHz, currently priced about £14 each from RS. https://www.google.com/url?sa=t&sour...AiqWGex3fnc8AR Looking at the datasheet, I'd be very surprised if any modern oscilloscope amplifier objected to these! Chris Williams I can still supply more CDU150 parts, including the dual transistors, if you have a blow–up emergency! __________________ It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed! Last edited by Chris55000; 22nd May 2020 at 1:45 pm.

22nd May 2020, 3:12 pm	#4
MelJon66 Pentode Join Date: Apr 2020 Location: Somerset, UK. Posts: 174	Re: Cossor CDU 150 Semiconductor Cross Reference List Hi Chris, Great information but they are a bit pricey to have just in case aren't they. If they blow I might take you up on your offer. I do need something for the Cossor now so I will PM you. Cheers Mel