5J T1 1000W lamp

[Rob the Spark]

Hello at my local community centre / am dram venue our front of house profiles are still Strand patt 264 units. Most of these have T19 1000W lamps, but some of them still have the old 5J lamps with a T1 base. 
 

We don’t have any spare lamps for the older units and I’m wondering if anyone here can point me in the direction of a supplier of the original lamp pattern or a conversion kit to enable the use of T19 lamps instead? I remember many years ago we got a load of conversion kits to upgrade our patt 23 and patt 123s from T1 lamps to T18 halogens. 
 

We have zero budget to work with so unfortunately replacing the units is not really an option. 
 

Any help would be greatly appreciated. 
 

 

These are the lamps I am looking for. 
 

Thanks!

[kgallen]

If of any use that looks like a P28 base - although since this is a 1kW lamp rather than 500W per the original  Patt23 T1 lamp maybe I’m wrong?

[sandall]

It is indeed a P28 base, but the photo is not a T11, but a T23, which has a longer body & is designed to run base-up (they still seem to be available in the US as Marine lamps). RB Lighting used to sell conversion kits from P28 to GX9.5 bases for T11 lamps & a conversion kit (basically a drilled ceramic block) to allow T11 lamps to be used in Patt.264s (which then had to be inverted, to run the lamp base-down).  I think the conversion kits were made by Jim Laws. There is a BR thread on 264s - 

 

[Jivemaster]

https://www.terralec.co.uk/halogen_lamps/1000w_230v_p28s_theatre_lamp_t15/18476_p.html

Look through their entire lamps section, consider changing the holder to something still in stock (but out of production). 

[Tomo]

I'd also strongly recommend starting putting together a plan to replace them with LED over the next few years.

While the 'common' theatrical halogen lamps are very unlikely to actually disappear altogether, they are going to get harder to buy and a lot more expensive over the next few years as the factories making them shut down.
You really don't want to be spending milspec or aviation type money on replacement lamps!

It won't be very long before they're like floppy disks and thermionic tubes - still available, but rare and possibly even collectible(!)
- 5-8 years ago there was only one place in the world making floppy disks. Now, nowhere does so anyone still using floppies is reliant on old stock.

[J Pearce]

I’d echo others in saying that at 50-60 years old these lanterns have done their service and it’s definitely time to put a solid plan together to replace them before the next 5-10 years.

Launch a campaign for a “energy efficient” lighting rig. Some well worded letters might attract funding too.

In the short term, some milled aluminium blocks will allow fitment of a more modern lamp. The important thing is to keep the centre of the filaments centred in the reflector. Your existing T19 modified units may even provide the pattern, copy what’s done in there, take it to a local engineering shop (or your local model engineering society?), and get some more made up.

[themadhippy]

The clips that hold the lens tube of 264's in place  have a nasty habit of breaking if theirs a budget for replacing stuff due to health and safety issues.

[Rob the Spark]

 

I’ve had a look today at one of the previously converted units and to be honest it doesn’t look like it would be too difficult to replicate, and I’ve found GX9.5 lamp holders on thomann for about £20 

 

As much as I’d love to see these units replaced with LED, it simply isn’t going to happen. The patt 264s are only 10 years old to them and were donated from a local school. To go LED they would need to upgrade to DMX first of all…

Edited January 8, 2022 by Rob the Spark
Clearer photo added

[sandall]

Yes that is the conversion kit I mentioned (it's a stand-off block on top of a P28/GX9.5 kit - aluminium blocks of course, not ceramic - if you have a tame metal-basher you could make your own), but T11 / T19 lamps don't like being run base-up (the filament falls off the hooks), so you should really rig the converted 264s upside-down (yes, they will look stupid, but your lamps might last into adulthood).

Edited January 8, 2022 by sandall

[Brian]

Making you own conversion kit is trivial if you have a few basic tools.

Aluminium bar can be had from eBay. Tool wise all you need is a hacksaw, drill, and M4 tap. A ceramic 'choc block' can be used to connect the leads from the new GX9.5 lamp holder to the existing.

[boatman]

I noticed that the two filaments in that photo appear to be at different heights above the baseplate. It might be worth checking which one is correct.

[sandall]

Well spotted. Looks like the bottoms of the filaments would line up within the adjustment-screws range, but the T11/T19 has a longer filament, so centering it might be problematical.

[Rob the Spark]

I reckon it should be pretty simple to knock up a conversion kit at work so I’ll give it a go and see how it turns out. 
 

 

these are the two different lamp types sat in their units and they both look pretty close to me. Is one of them better positioned than the other?

[mnorwood]

On 1/8/2022 at 5:33 PM, Rob the Spark said:

[...] and I’ve found GX9.5 lamp holders on thomann for about £20

I might possibly be able to save you even that much - I know of a venue in Yorkshire that took the opportunity of the Covid break to finish transitioning to a fully LED lighting rig. They now need to get rid of their old tungsten-based fixtures, and (AFAIK) are offering them away for free. There's no doubt several somethings there that you could cannibalise for their lamp holders.

Edited January 10, 2022 by mnorwood