Australian 109 set

[Mike Kelly]

Keith ,

Max's set has had a hole cut in the receiver next to the tuning dial for a speaker . this can be fixed . The 109 is a unique Australian designed set used in the early AIF campaigns in the Middle East and Malaya . I have one here in my collection .

I have the manual here for the set , plus a article written by Neil Wain from the signals museum at Watsonia barracks .

below is a part of a article I wrote for the VMVC newsletter , the 109 was still in use as late as 1944 in the Island campaigns . About 1500 made .


WIRELESS SET NO. 109 ( AUSTRALIA )

The 109 set appears to have a wholly Australian design history . Built by STC Ltd of Sydney
between 1939 and 42 this set was issued to AIF signals units and saw service in the Middle East
and Malaya . Also used in training situations in Australia . AWM photos reveal 109 sets mounted
in LP1 Bren Carriers in use with the 8 Div cavalry regiment training at Rokeby in West Gippsland
in October 1940. Used as a ground or vehicle station contemporary photos show the 109 set
installed in 1939-41 Ford GS 1 ton vans (utilities) in Syria and Palestine during 1940-42. For some
unknown reason it seems that during 1939-42 the Aust. army favoured Ford GS vans as wireless
trucks in preference to the Chevs of the time . In the field many sets were installed in the trucks in
a AD HOC fashion by the crews , wireless tables were made from scrap wood and photo evidence
has supported this . A standard wooden shelf type installation has also been noted in some
photos . The 109 set was built in a steel case measuring 25.5“ wide by 16.5” high with a chest style
lifting handle on each side . A clip on steel lid had the microphone and h / phones stored on
brackets inside the lid . A separate 6 volt vibrator power supply was used which required a
whopping 21 amps on transmit in CW ( morse code ) mode. Power output was around 10 watts RF.
A rare set as approx. only 1500 were built in various marks . Post WW2 these sets were used by
the CMF , civilian emergency radio networks and outback sheep stations in QLD into the late
1950’s . One survivor has a NSWGR ( Government Railways ? ) brass plate attached .

The pic below was taken in the ME , its a Ford GS van 1940 . Note the AD HOC way the radio table has been made and the seating arrangment !

Mike

[Max Hedges]

thanks Mike ,as I had no idea .The 109 was given to us by a retired farmer he thought there wwere a few others in the district when he got this one back a few years ago. perhaps I should store it in a safer place if there's not to many around.

Max

[Mike Kelly]

Last year , a 109 set to 109 set radio contact was made between VK3CZ ( me ) and VK5WT ( Andrew ) of Adelaide , South. Aust.

Using both AM ( voice ) and CW ( morse ) modes , the signals varied around S 5 - 7 . 3.5 Mhz band .


Probably hasn't been done for 50 years or more I would think . Crackle crackle sounds coming from headphones ...... didn't hear any Germans though .

Mike

[Mike Kelly]

The set on the table , ready to call VK5WT . The power supply requires 6 Volts DC at a hefty amperage . I used a big old telstra telephone exchange 6 Volt battery , it did the job well , didn't look like going flat .

The antenna was a temporary dipole , very low to the ground , centre fed with coax . The set puts out approx. 10-12 watts of carrier . Reported modulation was good , from the carbon Mic.

Mike

[Mike Kelly]

There is a temporary RF ammeter located where the original one has been , these are prone to burning out . The transmitter is the lower half , very simple design , and very easy to repair . There is provision for an optional XTAL , for locking the set , or you can the VFO . The VFO uses a very odd system of tuning , a roller inductor instead of the usual variable capacitor . After testing the VFO for a few hours , transmitting into a dummy load , and monitoring drift , I decided the VFO wasn't stable enough for on air use , I used a XTAL instead .

The antenna coupling circuit is rather basic , not very good at coping with highly varied antenna loads/impedances .

Mike