Righty ho ! Before I get into the promised telephony equipment , heres a little (actually quite big) beauty I found today
So yes its RAAF but could anyone explain to me what it is for and what it does? Love it though, looks remarkably good given that it was crammed into a corner!
***Update - Possible explanation from a reader -
" If you look on wartime photos of bombers and transports there is a directional loop antenna sticking out of the top of the fuselage - like a big basketball ring on edge. Used in plotting the bearing for transmitting stations to assist with navigation as I understand it. I imagine what you have is the graduated incremental rotater for that."
Now onto the phone materials, and this is just the first run of things I could bring back today. I was primarily tied down with scrap merchants visiting today for the stuff that is beyond saving for anyone ...
First up are some condensers - I assume these are for signal improvement, but am probably well off the path. Here are two Stromberg Carlson, one Western Electric and the little black one at the top is an IMP
***UPDATE - from a reader
"Telephones use a DC speech carrier modulated in sympathy with sound waves varying the resistance of the transmitter. The RING voltage is AC generated from the exchange, or another telephone with a hand generator. The condenser isolates the AC ring circuit from the DC speech circuit."
A shame this is in such bad condition, but I would love to know what was inside this - must have been a switching unit of some sort - all those tags in the middle still have something typed into them, like Secretary, Typist, Chairman, Clerk etc etc - just fascinating from an era long gone....
****UPDATE - from a reader
"The Western Eelctric tin cover is off one of their DC signalling intercom type phones. The sort of system with many stations in a large office or factory. They are interesting, but not wildy valuable, even when complete. The DESIGN is old, but they were produced for many years.
The Prot Blocks return !!! But this one is a sealed Western Electric box so I felt compelled to pop it in here for posterity :-)
Now I am stumped - I hand't seen these until today - any idea what they might be for? I am only assuming its phone related in some way.....
*****UPDATE - from a reader "The next things are EYEBALL INDICATORS. These superseded the old switchboard drop shutters, where the AC ring from the subscriber's phone generator energised a relay style magnet coil, which lifted a metal latch and dropped the shutter, revealing to the operator a number associated with the calling subscriber. What you have is the Eyeball, which was so arranged electrically as to wink down in response to incoming AC ring voltage from the subscriber's telephone, and so revealing the number painted on the eye. "
*****UPDATE - from a reader "The next things are EYEBALL INDICATORS. These superseded the old switchboard drop shutters, where the AC ring from the subscriber's phone generator energised a relay style magnet coil, which lifted a metal latch and dropped the shutter, revealing to the operator a number associated with the calling subscriber. What you have is the Eyeball, which was so arranged electrically as to wink down in response to incoming AC ring voltage from the subscriber's telephone, and so revealing the number painted on the eye. "
Given its wood base I believe this comes from an old exchange - not much other info I can provide, which is why I'm writing this blog in the hope someone out there knows the answers !
*****UPDATE - from a reader (same reader has been been invaluable this week - my sincere thanks!)
"The wood based HEDGEHOG COIL is a design where the functions of the laminations of a normal transformer are actually done using bundles of wires as a core. Yours is definitely Telephone, and may have been a matching coil used in early Common Battery telephony where a central battery at the exchange powered all phones. These types of transformers were part of an arrangement to smooth out fluctuations in battery voltage caused by conversations on different length lines. Another application for these transformers would be for matching an unbalanced telephone line to a balanced line in the days when such single-wire, earth return systems were in use. A farm single-wire line to the road would require a matching transformer to connect to the two-wire system out on the main road. Speech currents and also ringing voltages are thus transferred from one system to the other without causing any problems due to earthing the main two-wire transmission system. Other transformers of the same pattern on a similar base had six terminals, with centre taps on each of the 2 coils. These were used as part of a system to superimpose telegraph circuits on working phone lines without interference."
*****UPDATE - from a reader (same reader has been been invaluable this week - my sincere thanks!)
"The wood based HEDGEHOG COIL is a design where the functions of the laminations of a normal transformer are actually done using bundles of wires as a core. Yours is definitely Telephone, and may have been a matching coil used in early Common Battery telephony where a central battery at the exchange powered all phones. These types of transformers were part of an arrangement to smooth out fluctuations in battery voltage caused by conversations on different length lines. Another application for these transformers would be for matching an unbalanced telephone line to a balanced line in the days when such single-wire, earth return systems were in use. A farm single-wire line to the road would require a matching transformer to connect to the two-wire system out on the main road. Speech currents and also ringing voltages are thus transferred from one system to the other without causing any problems due to earthing the main two-wire transmission system. Other transformers of the same pattern on a similar base had six terminals, with centre taps on each of the 2 coils. These were used as part of a system to superimpose telegraph circuits on working phone lines without interference."
Any ideas as to what this is and how it was used - nice handwriting on back but cannot work out what it means ....
****UPDATE from a reader "The item is a single gong, DC interrupter type bell, used on doorbells and some simple house telephone intercom set ups. Missing gong,obviously."
****UPDATE from a reader "The item is a single gong, DC interrupter type bell, used on doorbells and some simple house telephone intercom set ups. Missing gong,obviously."
I found these under a mountain of rubbish - and was amazed that one still had globes in it !
Again, no idea other than possibly a relay/induction/retard coil....any help ?
****UPDATE - from a reader "The smaller coil on the wood base may be a later version of the hedgehog transformer above, for use in Central Battery telephone exchange systems as described, as far as I can work out. It is (British) Western Electric by part number"
****UPDATE - from a reader "The smaller coil on the wood base may be a later version of the hedgehog transformer above, for use in Central Battery telephone exchange systems as described, as far as I can work out. It is (British) Western Electric by part number"
Same for this, would be nice if they had part numbers but thats asking a little too much !!!!
****UPDATE from a reader "The next, skeleton looking, incomplete item on a wood base is part of yet another, quite early c.1900, DC interrupter type bell."
****UPDATE from a reader "The next, skeleton looking, incomplete item on a wood base is part of yet another, quite early c.1900, DC interrupter type bell."
Again no idea, but interestingly in the second photo, in top left hand corner of the unit is stamped PMG-30 which is something to do with PostMaster General....
*****UPDATE from a reader
"The PMG stamped item in your hand below that is yet another variety of aDC bell or mechanical buzzer, incomplete."
*****UPDATE from a reader
"The PMG stamped item in your hand below that is yet another variety of aDC bell or mechanical buzzer, incomplete."
??????????
****UPDATE from a reader "The thing with all the question marks on a wood panel is part of an array of electro-mechanical equipment to do with fire alarm monitoring.
****UPDATE from a reader "The thing with all the question marks on a wood panel is part of an array of electro-mechanical equipment to do with fire alarm monitoring.
Why would I put these in? Well they appear to have been from an exchange - there are loads and loads of them around the shed, some are beyond repair and others are pretty good.
****UPDATE from a reader "The terminal blocks on wood bases, last photo in this day's series, are exchange mainframe tag blocks. Part of the wiring arrangements allowing flexibility in connecting any outside pair of line wires to any inside circuit associated with an individual number on the exchange"
So thats the end of todays show and tell. There is still more phone stuff in the car and another mystery military object which again may be from a tank, but my back has gone again and I need to go cook dinner for my family :-)
Until next time .....
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