Field phone and switchboard inter-operability

[Chris Suslowicz]

Hi Gary,

Pre-WW2 was mostly buzzer call instruments: Telephone Sets D Mark III and III* in leather cases, and a 10 line exchange (Buzzer Switch Unit 7+3). (For working in the "Danger Zone" (within about 3000 yards of the enemy lines) the Fullerphone (a Direct-Current telegraph instrument - morse only) would be used to prevent interception by the enemy (this was "point to point" only, it had no "calling features" and couldn't work through an exchange.

WW2 saw the introduction of Telephone Set D Mark V, with buzzer calling and buzzer or magneto answering. It could do morse code or speech, but was still interceptable, so the Fullerphone was still used if interception was likely to be a risk.

Linemen continued to use the D Mark III or a GPO 110 telephone for portability.

The "Office Telephone" for higher formations was Telephone Set "F", which originally supported buzzer and magneto calling, but later had the buzzer replaced by an "induction coil" (audio transformer) for better speech quality.
(The Telephone Set "F" High Power was for use on long lines and had a valve audio amplifier built in (separate battery boxes required)).

There was also Telephone Set 'H' in the same casing as the "F", which was "sound powered" (dynamic inserts for microphone and earphone) for short distance use (rifle ranges and coastal guns, etc.)

Telephone Set 'L' in a pressed steel case replaced the Linemen's phones. It was more robust but not waterproof and was later replaced by Telephone Set "J" which was fully sealed and tropicalised - this also replaced the "D" range as the Army dropped buzzer signalling from newer equipment.

Switchboards:

Universal Call 6-line and 10-line were used in forward areas, they supported buzzer or magneto signalling and are reasonably portable.

F&F (Field and Fixed) was a modular exchange that could be broken down for transit. It could also be connected to the GPO telephone network. (I can't put my hand on its manual right now, and can't remember if it supports buzzer signalling - depends on whether the indicators are sensitive enough.) It was basically an "Office" exchange for headquarters that was light enough (Ha!) to be taken into the field, as well as being used in fixed installations and vehicles.

Magneto 10-Line (WD) was a later (magneto only) switchboard that was waterproof. It required a separate telephone (usually a 'J') for the operator.

Various "Wireless Remote Control" units could also act as magneto telephones.

The 19 set group has most of the manuals if you need more detail.

Best regards,
Chris.

[Mike K]

Most of the WW2 era British pattern field telephone equipment was also manufactured outside of Britain. Australia and Canada ( and N.Z. ? ) built copies of the field phones D mk V and switchboards.

I have a Aust. made Telephone F , have also seen L phones . Here, the Postmaster General (PMG) , operated the govt. owned communications network, the PMG operated their own factories where many thousands of wartime field phones were manufactured. The PMG ran just about everything, from the telephone system to amateur radio licensing and exams.A friend did his radio tech. apprenticeship in the PMG during the 1960s.

Used to buy D mk 5 phones for $10 but the recent prices have been going through the roof, up to $200. Just recently I spotted two "A" remote control units at $125 each, Aust. built for the W.S. 11.

I've seen many Australian built field sets that were supplied with a die cast alloy case, over time, the alloy corrodes into a white powder substance. Don't know if the alloy cases were also seen in other countries ?

[Chris Suslowicz]

Originally Posted by Mike Kelly

Most of the WW2 era British pattern field telephone equipment was also manufactured outside of Britain. Australia and Canada ( and N.Z. ? ) built copies of the field phones D Mark V and switchboards.

Yes, the British Empire/Commonwealth meant that lots of equipment was designed in the UK, then manufactured (where possible) for local use in other countries. I've got (I think) New Zealand made signals kit, an Australian tripod and bomb disposal telephones, and US and Canadian manufactured WS19s and ancillaries.

Changes were made for local manufacture: the Canadian Telephone Set 'D' Mark V has an aluminium (rather than steel) case, and the WS19 aerial base spacer is made of plywood (with cork gaskets) rather than rubber.

I have a Aust. made Telephone F , have also seen L phones . Here, the Postmaster General (PMG) , operated the govt. owned communications network, the PMG operated their own factories where many thousands of wartime field phones were manufactured. The PMG ran just about everything, from the telephone system to amateur radio licensing and exams.A friend did his radio tech. apprenticeship in the PMG during the 1960s.

Used to buy D mk 5 phones for $10 but the recent prices have been going through the roof, up to $200. Just recently I spotted two "A" remote control units at $125 each, Aust. built for the W.S. 11.

Prices have gone through the roof over the last few years, partly due to scarcity, but also due to people taking auction prices (where two people desperately want a particular item) as the actual value. Then there are the dealers (and optimists) waiting for the One True Sucker to appear and make them rich...

I've seen many Australian built field sets that were supplied with a die cast alloy case, over time, the alloy corrodes into a white powder substance. Don't know if the alloy cases were also seen in other countries ?

Canada made aluminium cased kit, because they had hydroelectric power to run aluminium smelters, and also wooden instead of rubber parts for similar reasons: locally available materials.

There's stuff I want for the collection available in Australia (Bags, Telephone Receiver - the forerunner of the "Satchel, Signals"), but shipping costs have also gone through the roof.

Too much stuff got melted down as scrap or buried in landfill.

Best regards,
Chris.