Thorn Gamma 6

Lantern acquired in July 2007.

This lantern is believed to have been used at the mobile home site near Alvaston Park but was replaced following problems with vandalism. Mercury Gamma 6s are rare here - the only examples being found in some car parks and Housing Association walkways. The use of a Q7 part-night cell is also rare - another indicator of the lantern's "non-street" use.

As with the SOX Gamma 6, this lantern has a deep canopy. As can be seen, the paint on the canopy has faded over the years, but unlike later versions, the paint has not worn away completely. Curiously, the base casting's paint hasn't faded especially badly, by comparison.


The lantern is equipped with a 3-BC lampholder for use with 80 - 125 W lamps; a lamp of the former type is employed here.


The lamp control gear is accommodated within the base casting. This comprises an 8 μF capacitor manufactured in October 1986 (an indicator of the lantern's age), along with a newer ballast.


Over eleven years after entering the Collection, restoration commenced on the lantern in October 2018. Very little work was required in returning the lantern to something akin to its condition upon leaving the factory. The canopy was repainted inside and out, as was the exterior of the base casting. With thanks to Nuns Street Plating for their assistance here.


External view - the apparent marks on the components here is, simply, airborne dust that settled on them during storage after repainting - a deft wipe of a damp cloth resolved this issue nicely!


With the bowl having been cleaned too, the lantern was reassembled and attached to a 76 mm diameter post-top stand. Its restored appearance putting the (newer) SOX Gamma 6 (to the left), and the Gamma Basique (to the right) to shame!


After being powered up, the lamp was up to full brightness within minutes.


Lamp warm-up video:

Testing the lantern with my energy monitoring device revealed the following results, and from these, that the capacitor was life-expired:

Test Voltage (V) Current being drawn at full power (A) Measured wattage (W) Apparent Power (VA) Frequency (Hz) Power Factor True Power (W) Difference (W) Percentage Difference
238.8 0.79 93 188 49.7 0.49 92.25 12.25 15%

GEC Z9532 | Relite Hyperion 'C'




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