Transistors type CDC8000 and CDC9000 - UK Vintage Radio Repair and Restoration Discussion Forum

Sideband · 22nd Sep 2008, 4:04 pm

Has anyone got data on these silicon transistors? They are used in the output stage of the comms receiver I'm repairing at the moment. I can best describe them as 'button' style transistors fitted flush to the PCB...probably about 4mm high and about 10mm dia. They are in a standard push-pull arrangement...one is NPN the other is PNP. Date back to about 1970.

Thanks for any info.

Rich.

davidw · 23rd Sep 2008, 10:24 am

The only place I can find CDC types is in a 1990 edition of Archer (Tandy) reference guide,which is very limited. It shows CDC8000 as their 276-1617 which in turn is replacable (according to Archer ) by 2N2222, NPN, 500mW, 60v, Si, TO18. HOWEVER it also shows a CDC8000-1 as MPS2222A,NPN 625mW,75v,Si, TO92.
The CDC9000 is only mentioned with suffix ie. 9000-1 which purports to be MPS2907 ,PNP,625mW,60v,Si,TO92.
I find this "reference" book limited as it reduces thousands of semiconductors down a few tens,presumably, those stocked by Tandy!!!
Hope this helps put you in the right area.

Sideband · 23rd Sep 2008, 10:33 am

Thanks Dave.

Limited info is better than no info!

I reckon I can find some Philips/Mullard transistors to replace those...seem fairly conventional types and ratings. If the 100uF speaker coupling capacitor hadn't been acting like a resistor of a few K, the originals may have survived!

Rich.

ppppenguin · 23rd Sep 2008, 10:47 am

I doubt that they will be critical. Any medium power silicon types should work. BFY50 series as an example for the NPN. 500mW seems a bit much for the 2N2222 which ISTR is in a TO18 can. 2N2218 is an NPN in TO5. 2N2907 is a PNP in TO5. Both are fairly HF devices so watch out for parasitic oscillation in an audio circuit.

Ray Cooper · 24th Sep 2008, 11:15 am

Quote:

...500mW seems a bit much for the 2N2222 which ISTR is in a TO18 can. ...

Point of information. Mr. Chairman...

According to the data I have, 2N2222 is indeed in a TO18 can and is rated at 500mW dissipation in free air at 25deg C. If you can heat-sink it so as to keep the case temperature down to 25deg C, you can push it up to 1.8watts.

Other statistics to boggle at: Vcb max 60V, Vce max 30V. Ic max 0.8Amp. fT better than 250MHz. hFE better than 100 at 150mA collector current.

Rather a meaty little device, then. If you want more dissipation you could try the 2N2219 which is exactly the same gizmo in a TO5 case, gives 0.8W dissipation free air, 3W heatsinked.

ppppenguin · 24th Sep 2008, 11:50 am

I have been reminded that the 2N2907 is in TO18 case. I meant 2N2905 which is in TO5.

Ray, I'm surprised the 2N2222 will dissipate up to 500mW but as usual, the secret is keeping it cool.

22nd Sep 2008, 4:04 pm	#1
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,577	Transistors type CDC8000 and CDC9000 Has anyone got data on these silicon transistors? They are used in the output stage of the comms receiver I'm repairing at the moment. I can best describe them as 'button' style transistors fitted flush to the PCB...probably about 4mm high and about 10mm dia. They are in a standard push-pull arrangement...one is NPN the other is PNP. Date back to about 1970. Thanks for any info. Rich. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

23rd Sep 2008, 10:24 am	#2
davidw Heptode Join Date: Sep 2006 Location: Woodbridge, Suffolk, UK. Posts: 643	Re: Transistors type CDC8000 and CDC9000 The only place I can find CDC types is in a 1990 edition of Archer (Tandy) reference guide,which is very limited. It shows CDC8000 as their 276-1617 which in turn is replacable (according to Archer ) by 2N2222, NPN, 500mW, 60v, Si, TO18. HOWEVER it also shows a CDC8000-1 as MPS2222A,NPN 625mW,75v,Si, TO92. The CDC9000 is only mentioned with suffix ie. 9000-1 which purports to be MPS2907 ,PNP,625mW,60v,Si,TO92. I find this "reference" book limited as it reduces thousands of semiconductors down a few tens,presumably, those stocked by Tandy!!! Hope this helps put you in the right area. __________________ Dave G1AGK. My perception is my reality!

23rd Sep 2008, 10:33 am	#3
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,577	Re: Transistors type CDC8000 and CDC9000 Thanks Dave. Limited info is better than no info! I reckon I can find some Philips/Mullard transistors to replace those...seem fairly conventional types and ratings. If the 100uF speaker coupling capacitor hadn't been acting like a resistor of a few K, the originals may have survived! Rich. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

23rd Sep 2008, 10:47 am	#4
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Transistors type CDC8000 and CDC9000 I doubt that they will be critical. Any medium power silicon types should work. BFY50 series as an example for the NPN. 500mW seems a bit much for the 2N2222 which ISTR is in a TO18 can. 2N2218 is an NPN in TO5. 2N2907 is a PNP in TO5. Both are fairly HF devices so watch out for parasitic oscillation in an audio circuit.

24th Sep 2008, 11:50 am	#6
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Transistors type CDC8000 and CDC9000 I have been reminded that the 2N2907 is in TO18 case. I meant 2N2905 which is in TO5. Ray, I'm surprised the 2N2222 will dissipate up to 500mW but as usual, the secret is keeping it cool.