Revo Diadem

Lantern acquired in September 2006.

This Diadem's history is unknown; however, it is painted bright green, which suggests that it was privately-owned. When received, a 50 W MBF lamp was employed; this has been replaced with a 70 W Philips CDO-ET, for variety. The Diadem is not a lantern that ever saw any sort of widespread use in Derby, though a few later Simplex Diadem Major lanterns exist in private ownership.

This Diadem is in excellent condition - someone has kept the green paint on the canopy looking fresh. It is a very narrow lantern - such as was typical in 1960s design.

A two-part photocell detector has been added to the canopy at some point; this was connected to a Royce Thompson PNQ part-night photocell.

The design of the glass bowl reminds me of wall lanterns dating from the same era.

The inside of the canopy looks fairly freshly painted as well - there is a water stain and some specks of dirt but no scorch marks from the lamp are present - I suppose the part-nightly operation of the PNQ helped to keep the insides from blackening. 


The lantern was cleaned and was then fitted to an AC Ford AC872 wall bracket on Friday, 27th October 2006. The green canopy was retained - despite the colour being controversial amongst collectors! Visible behind the lantern is the Iwasaki clear 50 W MB/U lamp, which I used as an 'alternate' lamp when I wanted to change from the usual mercury colour. Notice that a P42-style photocell detector is now fitted; not that it is connected to anything.

Once wired up, the lantern was switched on. The 50 W lamp meant that the light output was not immense but it would provide enough for a small area.

The clear lamp gave out a much greener light - though at least the output colour now matched the canopy!

As the bowl was designed to diffuse the light of a coated elliptical lamp, a less focused beam is given out with the clear lamp.

Testing the fitting with my energy monitoring device revealed the following results:

Test Voltage (V) Current being drawn at full power (A) Calculated wattage (W) Apparent Power (VA) Frequency (Hz) Power Factor True Power (W)
238.3 0.29 60 69 49.8 0.86 59.43
 
 

The lantern was converted to 70 W CDO-ET on Wednesday, 13th May 2009. Naturally the 'warmer' colour temperature altered the appearance of the lantern when in use, however as the replacement lamp was the same physical size and shape as that of an 80 W MBF, the bowl refractors correctly focused the light output.

Lantern warm-up video:

Re-testing the fitting with the energy monitoring device revealed the following results:

Test Voltage (V) Current being drawn at full power (A) Calculated wattage (W) Apparent Power (VA) Frequency (Hz) Power Factor True Power (W)
236.9 0.40 81 95 49.9 0.88 83.39

Abacus AM480 | GEC Z5699


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