By: hindenburg - 23rd January 2013 at 12:45
Yes that sounds like a Halifax installation,I`ve seen them in Stirlings and Wellingtons too.I`ll post a picture of the strange unit on my thread later..and the 1134 and crystal monitor.
By: AndyY - 23rd January 2013 at 11:44
Yes, radio and avionic systems are definitely my ‘thing’!
The Crystal Monitor Type 2, the A1134 and the T1083/R1082 are all very much the same prewar-design generation of equipment.
The radio installation picture I saw with the Xtal Monitor Type 2 with the T1154/R1155 was the one where the R1155 is installed on one end rather than on its bottom. Was that the Halifax installation?
Usually close by the A1134 you would see the Plugboard which interconnects the intercom with the radio systems.
Andy
By: hindenburg - 23rd January 2013 at 11:22
You seem to know your radio stuff AndyY,I`ve found a picture of the Monitor and 1134 Amp unit fitted with the 1082/83 radio equipment (will post a pic when my PC lets me).I have pics of the 1154/55 set up which shows a 1134 amp..can`t make out whats fitted above this though.Not wishing to distract from this thread,I wonder if I posted a picture of radio unit on my thread (stirling bits)..you could ID it for me??
By: AndyY - 23rd January 2013 at 08:12
The Type 4, as a VHF unit, wasn’t relevant to the T1154/R1155 HF installation.
The applicable unit here would have been the Crystal Minitor Type 2. I haven’t seen a picture showing one fitted as part of the installation in the Lancaster, but I have seen a picture showing one as part of the installation in a Halifax, or was it a Stirling, I can’t remember for sure.
The Type 4 is rack-mounted and mains powered, so probably intended for ground use only.
Andy
By: thedawnpatrol - 22nd January 2013 at 21:31
I take it they were a ground based unit ? or were they fitted in Aircraft ?
Jules
By: hindenburg - 22nd January 2013 at 19:23
Were the monitors used with the 1134 Amp and 1154/55 set-up ??
By: AndyY - 22nd January 2013 at 09:59
Details of the Crystal Monitor Type 4, 10T/46, are given in A.P.1186A, it is a unit ‘designed to deliver a small modulated radio frequency signal in the range 100 – 130 Mc/s for the calibration of VHF receivers’. It is a 19″ rack-mounted unit, 7″ high.
The question is, are the ‘Type 4’ and ‘Type 4a Tropical’ at all similar?
Andy
By: Arabella-Cox - 20th January 2013 at 23:11
Sometime around 1980 I was shown around the RAFs crystal manufacturing facility at RAF Henlow. What I recall the clearest is the dipping to electroplate gold on the crystal to reach the correct frequency before it wsa inserted in its can.
I have one of the raw crystals somewhere, I’ve kept it just because it was what I considered large in a time of electronics and microchips. Its an inch square by quarter of an inch thick of quartz.
At the time we (RAFSEE) were engineering some powerful radars and HR transmitters for the RAF and it always made me smile when I heard the radio one jingle about having 1 millon Watts of power – only one, we were playing with Mega Watts in double figures.
By: Airspeed Horsa - 20th January 2013 at 22:26
The “crystal” it refers to will have been quartz frequency crystals – precision cut squares of quartz mounted within a rectangular bakelite-esqe casing. Two sturdy pins made contact with the crystal and the assembly plugged into a transmitter to determin it’s output frequency. I have several dozen and shall try to dig one out.
I’m guessing the monitor was used to verify the transmitted output matched what was marked on the crystal, as they can drift with variations in temperature, vibration or aging.
Rob
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January 20, 2013 at 6:28 pm