Remember when searching for info on the CR100 to include in the search 'B28' and R1297 - same set, depending on whether used by the Army, Navy, or RAF. Such a complex set, rather like Racals, that you never quite know whther it's working right or not, without the necessary test gear. A much under-rated set in my view far superior to sets such as R1155's, which enjoy an iconic status that isn't backed up by its basic spec.
Some sites you night find helful Al are:
http://www.philipstorr.id.au/radio/sixte...s_rx11.htm
He undertook a complete restoration - a total stripdown and rebuild, which is very well illustrated on his site. Some of his comments are:
"I searched the internet for details of the B28/CR100 and I found quite a few pages devoted to restoration and I even found the original workshop manual on the Boat Anchor site. From reading the stories of peoples restorations I soon realised I would have to replace all twenty two 0.1 uF chassis mount capacitors as they were always leaky twenty years ago so what is the chance of any of them being OK today. The electrolytics had already been replaced but as that was perhaps forty years ago they all had to go also. Getting the chassis mount caps out proved to be more difficult than I thought and I soon realised whoever had replaced a lot of the wiring thirty or forty years ago had made a mess of it".
"Well in for a "penny in for a pound", take the thing apart and replace all the caps, most of the resistors and all the wiring. While ripping it apart I discovered some old pitch covered caps deep inside the coil shields. To my relief I soon discovered the receiver was made to come apart, right down to the shields around each coil assembly, making replacing the bits around the coils quite easy. Just as well I reduced to a big box of bits, the wiring in the coil assemblies left a lot to be desired. In investigating the IF coils I found the BFO coil is open circuit but as the "opening" is where it terminates on a capacitor I should be able to fix it".
End quote.
I don't know if you've downloaded Chris Parry's excellent 'e-book' on the restoration of Military radios, but if not, it can be found here:
http://www.vk2bv.org/radio/radio-files/r...050723.pdf
There's an interesting article about screen printing a new front panel for a CR100, albeit you aren't contemplating that:
http://www.jonkster.com/radio/
Hope that's of interest.
A lot of these military radios - AR88s, HROs etc, like the CR100 B28 etc, are very cheap because of the sheer size, weight, complexity, and the fact that some don't lend themselves to non-military use without considerable modification. I once stripped an 1155 back to the IFTs and coilpack and rebuilt it with modern valves, based on an article in Short Wave mag. I plated all the original valvholder holes to fit B9 valveholders, built in a PSU and audio stage, fitted an 'S' Meter, made a new front panel. It was quite an undertaking, but the end result was far superior to the 1155, which I considered only fit as a donor.
Best of luck with the restoration Al!
Some sites you night find helful Al are:
http://www.philipstorr.id.au/radio/sixte...s_rx11.htm
He undertook a complete restoration - a total stripdown and rebuild, which is very well illustrated on his site. Some of his comments are:
"I searched the internet for details of the B28/CR100 and I found quite a few pages devoted to restoration and I even found the original workshop manual on the Boat Anchor site. From reading the stories of peoples restorations I soon realised I would have to replace all twenty two 0.1 uF chassis mount capacitors as they were always leaky twenty years ago so what is the chance of any of them being OK today. The electrolytics had already been replaced but as that was perhaps forty years ago they all had to go also. Getting the chassis mount caps out proved to be more difficult than I thought and I soon realised whoever had replaced a lot of the wiring thirty or forty years ago had made a mess of it".
"Well in for a "penny in for a pound", take the thing apart and replace all the caps, most of the resistors and all the wiring. While ripping it apart I discovered some old pitch covered caps deep inside the coil shields. To my relief I soon discovered the receiver was made to come apart, right down to the shields around each coil assembly, making replacing the bits around the coils quite easy. Just as well I reduced to a big box of bits, the wiring in the coil assemblies left a lot to be desired. In investigating the IF coils I found the BFO coil is open circuit but as the "opening" is where it terminates on a capacitor I should be able to fix it".
End quote.
I don't know if you've downloaded Chris Parry's excellent 'e-book' on the restoration of Military radios, but if not, it can be found here:
http://www.vk2bv.org/radio/radio-files/r...050723.pdf
There's an interesting article about screen printing a new front panel for a CR100, albeit you aren't contemplating that:
http://www.jonkster.com/radio/
Hope that's of interest.
A lot of these military radios - AR88s, HROs etc, like the CR100 B28 etc, are very cheap because of the sheer size, weight, complexity, and the fact that some don't lend themselves to non-military use without considerable modification. I once stripped an 1155 back to the IFTs and coilpack and rebuilt it with modern valves, based on an article in Short Wave mag. I plated all the original valvholder holes to fit B9 valveholders, built in a PSU and audio stage, fitted an 'S' Meter, made a new front panel. It was quite an undertaking, but the end result was far superior to the 1155, which I considered only fit as a donor.
Best of luck with the restoration Al!
Regards, David.
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
