Cossor transistor radio identification. Identified as a CR7243T. - UK Vintage Radio Repair and Restoration Discussion Forum

Thripster · 24th Jun 2019, 4:57 pm

Hello, I am looking for help in identifying the radio pictured please. I have opened the case and there is no indication of model number. I would be grateful. Thanks.

Maarten · 25th Jun 2019, 11:01 am

The type label should be in the battery compartment. Also, there should be a chassis label on the pcb or chassis.

Thripster · 25th Jun 2019, 11:19 am

Thank you Maarten, there is no identification label in the battery compartment. I think it must have fallen off long ago. There is no discernible label on the component side of the PCB or chassis. I am keen to obtain a service sheet in order to know how to remove the PCB from the front of the radio without the possibility of disturbing the tuning cords. But if not forthcoming, I will have a look in the next few weeks.

dazzlevision · 25th Jun 2019, 12:00 pm

At the time this radio was made (early to mid 1960s), Cossor was a brand name used in the UK by Philips.

There will almost certainly be a Philips branded equivalent model, which will be identical internally to the Cossor badged radio. Although, your radio being made in Denmark, is a little unusual for a Cossor radio during the Philips "badge engineering" era.

A photo of the internals will assist in identifying the radio.

Thripster · 25th Jun 2019, 12:37 pm

Thank you dazzle, I'll get onto that this pm.

Thripster · 25th Jun 2019, 1:15 pm

Here are some pictures of the internals, which I hope may help.

paulsherwin · 25th Jun 2019, 2:40 pm

This looks rather like it: https://www.radiomuseum.org/r/philip...m_ldk453t.html

Thripster · 25th Jun 2019, 2:59 pm

Agreed Paul, that is very similar - but not quite. Still, it gives me another variant to search for. Thank you.

AC/HL · 25th Jun 2019, 3:23 pm

A bit clearer here: https://www.doctsf.com/ldk-453-t-fam...e334c2ac81e535

Herald1360 · 25th Jun 2019, 3:28 pm

I hope it works...... it looks like it's stuffed full of AF11x series RF transistors which are renowned for tin whiskers shorting out the chip inside

Thripster · 25th Jun 2019, 3:32 pm

Very interesting, thank you. That has to be the same base model though I note it has four auxiliary controls on the top surface as opposed to my two. (The two push buttons on the top of my model which are separate from the on/off and wave change switches control a bulb to light the clear perspex display. At least the RHS button does, the LHS button does not appear to do anything. From memory, the LHS button lit the display bulb as well.)

I have a query out with Philips who promise to respond in 24 working hours - I'll let you know what I hear from them. Many thanks for your help so far.

Thripster · 25th Jun 2019, 3:35 pm

Hi Herald, yes it works on VHF and has a very clear sound. The SW/MW and LW functions do not work so needs to be investigated which is why I am intent on finding the exact service sheet if possible. I haven't explained here but I used to have one of these in the early eighties but was lost in my mothers house clearance. I have recently managed to obtain this item so an interesting project.

paulsherwin · 25th Jun 2019, 5:27 pm

Changing AF11x transistors (if necessary) is usually easy unless physical access is difficult.

Thripster · 25th Jun 2019, 8:01 pm

Yes, thanks Paul. I cannot easily see how the PCB is removed from the front cover - I am hoping that a service manual will explain.

Regards

Herald1360 · 25th Jun 2019, 10:51 pm

Sounds like the AF11x are still OK then- they're used on all wavebands.

crackle · 26th Jun 2019, 10:45 am

Searching Radio Museum for Philips, Denmark came up with another model, this time with a list of the transistors.
Putting into the Radio Museum's advance search facility the transistor list from one of the similar models and wavebands we have a short list cossor radios.xls of possible similar radios.
The most likely in my view is the French Radiola RA7243T

There does not seem to be any information on removal of the chassis.

Mike

Thripster · 26th Jun 2019, 11:09 am

Crackle,

I am very grateful for this information. Hopefully this new information will allow me to get closer to the true identity.

Thripster · 26th Jun 2019, 11:19 am

Crackle, having had a look at the links provided, I agree that this is it. Would it be fair to suggest that the same design was licensed for production by two (or more) manufacturers in different countries?

Andrewausfa · 26th Jun 2019, 11:53 am

Seems it wasn't just Cossor and Radiola who re-badged this set. More from our counterparts in Holland.

Andrew

http://www.transistorforum.nl/forum/...thread&id=6628

Thripster · 26th Jun 2019, 11:58 am

OK, I think I have it. Based upon Crackle's information I believe this to be a Cossor CR7243T. The only reference I have found for it is in an online document https://www.americanradiohistory.com...PW-1964-11.pdf which highlights pages from a 1964 edition of PW. This disusses new release radios and confirms ten transistors with a price tag of 38 guineas! A considerable sum. The hacker sovreign 18 is listed at 39 gns in the same article. I do not take any credit for the information printed in that PDF file.

24th Jun 2019, 4:57 pm	#1
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Cossor transistor radio identification. Identified as a CR7243T. Hello, I am looking for help in identifying the radio pictured please. I have opened the case and there is no indication of model number. I would be grateful. Thanks. Attached Thumbnails

25th Jun 2019, 11:01 am	#2
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: Cossor transistor radio identification The type label should be in the battery compartment. Also, there should be a chassis label on the pcb or chassis.

25th Jun 2019, 11:19 am	#3
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Thank you Maarten, there is no identification label in the battery compartment. I think it must have fallen off long ago. There is no discernible label on the component side of the PCB or chassis. I am keen to obtain a service sheet in order to know how to remove the PCB from the front of the radio without the possibility of disturbing the tuning cords. But if not forthcoming, I will have a look in the next few weeks.

25th Jun 2019, 12:00 pm	#4
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,608	Re: Cossor transistor radio identification At the time this radio was made (early to mid 1960s), Cossor was a brand name used in the UK by Philips. There will almost certainly be a Philips branded equivalent model, which will be identical internally to the Cossor badged radio. Although, your radio being made in Denmark, is a little unusual for a Cossor radio during the Philips "badge engineering" era. A photo of the internals will assist in identifying the radio. Last edited by dazzlevision; 25th Jun 2019 at 12:09 pm.

25th Jun 2019, 12:37 pm	#5
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Thank you dazzle, I'll get onto that this pm.

25th Jun 2019, 1:15 pm	#6
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Here are some pictures of the internals, which I hope may help. Attached Thumbnails

25th Jun 2019, 2:40 pm	#7
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,937	Re: Cossor transistor radio identification This looks rather like it: https://www.radiomuseum.org/r/philip...m_ldk453t.html

25th Jun 2019, 2:59 pm	#8
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Agreed Paul, that is very similar - but not quite. Still, it gives me another variant to search for. Thank you.

25th Jun 2019, 3:23 pm	#9
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Cossor transistor radio identification A bit clearer here: https://www.doctsf.com/ldk-453-t-fam...e334c2ac81e535

25th Jun 2019, 3:28 pm	#10
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Cossor transistor radio identification I hope it works...... it looks like it's stuffed full of AF11x series RF transistors which are renowned for tin whiskers shorting out the chip inside __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

25th Jun 2019, 3:32 pm	#11
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Very interesting, thank you. That has to be the same base model though I note it has four auxiliary controls on the top surface as opposed to my two. (The two push buttons on the top of my model which are separate from the on/off and wave change switches control a bulb to light the clear perspex display. At least the RHS button does, the LHS button does not appear to do anything. From memory, the LHS button lit the display bulb as well.) I have a query out with Philips who promise to respond in 24 working hours - I'll let you know what I hear from them. Many thanks for your help so far.

25th Jun 2019, 3:35 pm	#12
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Hi Herald, yes it works on VHF and has a very clear sound. The SW/MW and LW functions do not work so needs to be investigated which is why I am intent on finding the exact service sheet if possible. I haven't explained here but I used to have one of these in the early eighties but was lost in my mothers house clearance. I have recently managed to obtain this item so an interesting project.

25th Jun 2019, 5:27 pm	#13
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,937	Re: Cossor transistor radio identification Changing AF11x transistors (if necessary) is usually easy unless physical access is difficult.

25th Jun 2019, 8:01 pm	#14
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Yes, thanks Paul. I cannot easily see how the PCB is removed from the front cover - I am hoping that a service manual will explain. Regards

25th Jun 2019, 10:51 pm	#15
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Cossor transistor radio identification Sounds like the AF11x are still OK then- they're used on all wavebands. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

26th Jun 2019, 10:45 am	#16
crackle Rest in Peace Join Date: Mar 2011 Location: Basildon, Essex, UK. Posts: 4,100	Re: Cossor transistor radio identification Searching Radio Museum for Philips, Denmark came up with another model, this time with a list of the transistors. Putting into the Radio Museum's advance search facility the transistor list from one of the similar models and wavebands we have a short list cossor radios.xls of possible similar radios. The most likely in my view is the French Radiola RA7243T There does not seem to be any information on removal of the chassis. Mike Last edited by crackle; 26th Jun 2019 at 10:53 am.

26th Jun 2019, 11:09 am	#17
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Crackle, I am very grateful for this information. Hopefully this new information will allow me to get closer to the true identity.

26th Jun 2019, 11:19 am	#18
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification Crackle, having had a look at the links provided, I agree that this is it. Would it be fair to suggest that the same design was licensed for production by two (or more) manufacturers in different countries?

26th Jun 2019, 11:53 am	#19
Andrewausfa Octode Join Date: Dec 2010 Location: St Ives, Cambridgeshire, UK. Posts: 1,180	Re: Cossor transistor radio identification Seems it wasn't just Cossor and Radiola who re-badged this set. More from our counterparts in Holland. Andrew http://www.transistorforum.nl/forum/...thread&id=6628 __________________ Invisible airwaves crackle with life. Or they should do. BVWS Member

26th Jun 2019, 11:58 am	#20
Thripster Retired Dormant Member Join Date: Jun 2019 Location: Northampton, Northamptonshire, UK. Posts: 21	Re: Cossor transistor radio identification OK, I think I have it. Based upon Crackle's information I believe this to be a Cossor CR7243T. The only reference I have found for it is in an online document https://www.americanradiohistory.com...PW-1964-11.pdf which highlights pages from a 1964 edition of PW. This disusses new release radios and confirms ten transistors with a price tag of 38 guineas! A considerable sum. The hacker sovreign 18 is listed at 39 gns in the same article. I do not take any credit for the information printed in that PDF file.