Post by trombone on Aug 8, 2020 13:38:13 GMT 12
Perhaps in childhood,like me ,you made"tanks".You hammered 4 carpet tacks into the end of a wooden cotton reel,wound a long rubber band round the heads of the tacks and threaded the rubber band down through the hole and then looped the other end of the rubber band over a stick about 2 1/2 - 3 inches long. Grasping the cotton reel between thumb and fore finger of the left hand you would twirl the stick round and round winding up the rubber band like the propeller of a rubber powered plane and put the "tank" on the floor.As the rubber unwound the "tank "would lumber across the lino ,its clumsy gait mimicking the action of a WW1 tank. And sometimes flipping right over,again ,sadly, authentically. A washer between the stick and the reel and some candle grease made your "tank" perform better than your sister's.Such were the pastimes of childhood.
Nowadays ,in an attempt to secure the moral high ground in the oceans of waste in which we live we call making a toy from a cotton reel "re-purposing".
Recently I put on the bench a 1947 Chevrolet car radio Model B47. There's a picture of one on Radio Museum.It is an "in dash" set boasting a lineup of loctal valves (bar the OZ4 rectifier),permeability tuning with four push buttons,a tone control slide switch and volume and tuning controlled by thumb wheels.Except that the tuning thumb wheel didn't work as the dial cord was broken. If you do look up the illustration on Radio Museum you'll see that the dial is a small rotating drum,turned, when all is as it should be , by the thumb wheel.Not so in this case.
Time to "go in".
There,once the plastic escutcheon had been removed , was "re purposing" from a bygone era.
Where there should have been a translucent plastic drum with the frequency numbers printed on was now a humble cotton reel ,obtusely opaque, but sporting a bit of paper tape from which the hand written N.Z. station designations had long since faded.I say "obtusely opaque" because the Chev engineers had carefully arranged a dial light cleverly hooded but with a tiny hole to focus the light through the original and translucent drum so the station chosen would be visible.
I didn't recognise this as the dial light at first .The hood made it look like a greasy paper capacitor.
The set now goes .Hooked up initially to the bench power supply each stage proved lively.The converter ,noisy at first ,quietened gratifyingly once the valve prongs had been given a scrape.Long ago a kind person had replaced most of the caps with (now elderly ) plastic caps and that same person may have been responsible for the replacement of the original e.m. speaker with a p.m.Though it has no R.F. stage the set seems sensitive .The original vibrator was not a go-er but I found one that did work. Later I fitted a solid state one made by a colleague here in Ch Ch which performed exceptionally well.
Hint for young recruits - don't leave the vibrator in ,especially one with frozen contacts, when you hook the filaments up to the bench 6.3 volt supply for initial testing.
Why put all this tedious and long winded blether onto general chat? Okay - Does any one know what sort of plastic I should get to fabricate a new dial drum? Can they recommend a supplier? Cheers everyone.
Nowadays ,in an attempt to secure the moral high ground in the oceans of waste in which we live we call making a toy from a cotton reel "re-purposing".
Recently I put on the bench a 1947 Chevrolet car radio Model B47. There's a picture of one on Radio Museum.It is an "in dash" set boasting a lineup of loctal valves (bar the OZ4 rectifier),permeability tuning with four push buttons,a tone control slide switch and volume and tuning controlled by thumb wheels.Except that the tuning thumb wheel didn't work as the dial cord was broken. If you do look up the illustration on Radio Museum you'll see that the dial is a small rotating drum,turned, when all is as it should be , by the thumb wheel.Not so in this case.
Time to "go in".
There,once the plastic escutcheon had been removed , was "re purposing" from a bygone era.
Where there should have been a translucent plastic drum with the frequency numbers printed on was now a humble cotton reel ,obtusely opaque, but sporting a bit of paper tape from which the hand written N.Z. station designations had long since faded.I say "obtusely opaque" because the Chev engineers had carefully arranged a dial light cleverly hooded but with a tiny hole to focus the light through the original and translucent drum so the station chosen would be visible.
I didn't recognise this as the dial light at first .The hood made it look like a greasy paper capacitor.
The set now goes .Hooked up initially to the bench power supply each stage proved lively.The converter ,noisy at first ,quietened gratifyingly once the valve prongs had been given a scrape.Long ago a kind person had replaced most of the caps with (now elderly ) plastic caps and that same person may have been responsible for the replacement of the original e.m. speaker with a p.m.Though it has no R.F. stage the set seems sensitive .The original vibrator was not a go-er but I found one that did work. Later I fitted a solid state one made by a colleague here in Ch Ch which performed exceptionally well.
Hint for young recruits - don't leave the vibrator in ,especially one with frozen contacts, when you hook the filaments up to the bench 6.3 volt supply for initial testing.
Why put all this tedious and long winded blether onto general chat? Okay - Does any one know what sort of plastic I should get to fabricate a new dial drum? Can they recommend a supplier? Cheers everyone.