A Marconi CR.100 dilemna.

[Yorkie]

Thank you gentlemen for your replies: insightful and informative.

First, as promised, there are some photos. below. Andy: silicon rubber-covered wiring; sounds good: I will look into it.

Alan: I will contact Phil via P.M. on this. Al. / Nov. 21, 2011 //
 

Hi name is Phil Marrison and he's a really nice guy. He started getting reels of the wire for his own restorations, but the minimum quantity (I think 100M) was higher than his own requirments so he started to sell it to fellow enthusiasts. I've been buying it from Phil for some years and haven't found anything better. I've mentioned in other posts that it's in a wide range of 'vintage' colours, unlike gaudy modern PVC wire which is totally out of keeping with our requirments, and unlike PVC, the wire is heat proof, strips very easily and is nice and flexible. It comes in two gauges, but the actual sizes eludes me.

Frankly, it's remarkable that so many of these old military radios - especially R1155s - have survived well beyond their intended or expected lifespan. Although we tend to think that they were built to last, in fact they weren't. True, they were well built and rugged as befitted their role, but the life-span of a bomber in WW2 averaged about 17 weeks. The cold reality is that in 1942, less than half of all bomber crews would survive their first tour, and one in five wouldn't make it through a second. In 1943, the picture was even more grim - one in six could expect to survive their first tour, and just one in forty their second. In trainnig, me were told that if shot down, there was a realistic chance of survival, but that was rarely the case. In the 'Battle of Berlin' of 4,319 men aboard the 607 heavy bombers shot down, just 992 (22.9%) survived. The odds depended on which aircraft you were in - despite their reputation for ruggedness and reliaiblity, Lancasters were difficult to escape from. Of a seven-man crew in a doomed bomber, survival rates averaged: Lancaster 1.3 , Stirling 1.8, Halifax 2.45.

I appreciate that I'm rambling right off-topic, but it does serve to illustrate why it made little sense to make things such as radios to be any other than reliable for their short expected life-span, with longevity the last thing on the mind of the designers. There are two ways of viewing the actual life of the end product. Namely, as a testment to good design and manufacture that they're still in good shape today, or as a lack of understanding back in the 1940s of what has become known as 'limit state technnology' whereby things are designed only to last as long as their intended/expected life. Anything that goes beyond that is needless redundancy. To put this into a modern context, we don't need cars that are built like tanks, but cars that are built like cars, and that's what we get - cars which are built with crumple zones to maximise our chance of survival in a collision.

Whichever way this is viewed, the fact is that as restorers, we have benefitted greatly from this 'over-engineering' of old radios, both military and civilian, and with care and enthusism, are capable of making this old kit factory fresh again!

Al's CR100 does in fact look in quite good shape from the pics.

I hope these largely irrelevant ramblings are of passing interest.