Conventional Fixtures Radial Altman Porcelains

[BLPisani]

I'm working on an older rig, getting ready to do maintenance over the winter. I need to replace the sockets in some caps on old radial Altman 360s. The TD has been able to get similar sockets that don't quite work. (They seem more like they're for fresnels.) Anyone have a source for the right thing?




Thanks in advance.

 

[Les]

There shouldn't be an operational difference between these and fresnel sockets, as there weren't any medium prefocus sockets made specifically for fresnels vs ellipsoidals (Altman used this same part no. in their 65/Q fresnel at the time). That said, you may encounter some differences due to age and manufacturer -- meaning you may have to re-drill some holes in your mounting plates.

Were there any other differences that concerned you?

Keep in mind that the ellipsoidals use the EGG/EGE lamps, which are physically longer with a greater LCL; not the BTN, BTL, BTR, and BTH's which are used in many fresnels. They are too short.

 

[BillESC]

That's Altman's part # 58-0018

 

[BLPisani]

Yeah, the center contact is made quite differently. The old ones are about twice the width of the new ones, and they make much better contact. I have to replace some of the newer sockets already. Here's a photo of a newish one:

We are trying to update the rig, but economic times are tough and maintenance is a bit cheaper, even with this older gear.

 

[Les]

That's Altman's part # 58-0018

Correct me if I'm wrong, but is the 58-0018 not a TP-22 socket meant for the Shakespeare, 360Q, etc? The OP seems to have radial ellipsoidals (P28s socket).

That contact issue you're encountering is likely just a sign of the times (and differences between individual suppliers). The base of the BTN, BTL, etc fresnel lamps are identical to the EGG/EGE bases, thus the same sockets are used. Your best bet might be contacting manufacturers (like Bryant, Osram, etc; not Altman, ETC) and see if their model offers the larger center contact you desire.


Mark DeLorenzo (DELO72) works at Osram Sylvania. Maybe he can be of assistance.

 

[MPowers]

.......to replace the sockets in some caps on old radial Altman 360s........

Just a note from an old timer. When the first ERS models were introduced with the lamp mounted on the axis of the unit instead of BBU, Burn Base Up, we called them Axials, rather than Radials. We never did have a name for the units that used a double ended lamp and a two part reflector. Well....that is, never a name that can be repeated in polite company. They had a VERY short production life and, thankfully, have long since faded into oblivion except for a few that are still out there, some how still working, in a manner of speaking.

 

[BLPisani]

Thanks all, esp. Les. I did see Bryant on one of the ones I was fixing up today. I'll recommend it to my TD.

 

[Les]

Glad I could be of help! We have had some questions here regarding newer sockets burning up faster than expected in fresnels. Seems that the lamps could be to blame in some cases. I haven't experienced it personally, but I've heard that some lamps have a small solder 'blob' on the bottom, which creates a very small point of contact. The bottom of the lamp should be slightly convex, but not too much so, or it won't sit against the center contact correctly. You might look in to that and see if you can alleviate the problem by using a different lamp supplier. Hopefully Mark from Osram will chime in here (or ship) because they can answer any questions we may have about lamps and sockets -- and even answer questions we didn't know we had ;-).

Here are some previous threads that might be of interest or use:
http://www.controlbooth.com/forums/lighting-electrics/22505-lifespan-65q-socket.html
http://www.controlbooth.com/forums/lighting-electrics/25523-stuck-6-altman-fresnel-lamp.html

 

[derekleffew]

That's Altman's part # 58-0018

2008 Altman Parts List has
Part#, Description, MSRP:
97-1585, Medium Pre-Focus Socket Kit 58-0010 Resale Components, $22.00.
Listing on Altman's site has it at $18, may be out of date.
This listing indicates some (seeming) equivalents.

My 360-6x12 has an unglazed (matte finish) white Bryant socket:

... I haven't experienced it personally, but I've heard that some lamps have a small solder 'blob' on the bottom, which creates a very small point of contact. The bottom of the lamp should be slightly convex, but not too much so, or it won't sit against the center contact correctly. ...

Actually, the old "solder blob" has/had more contact surface area than the new style.

Old EGJ on the left; new EGG on the right; conveniently both Philips, made at least twenty years apart

Sorry, I don't have an MPF (medium prefocus) socket made in the last twenty-five years to compare--all of mine have a flat disc in the bottom. Do the new sockets have a divot or recess in the spring-loaded "button"?

There's something ship has said about gray sockets vs. glossy white sockets that I can never remember. I don't think I have any grey sockets to compare with.
EDIT: This post: http://www.controlbooth.com/forums/...refocus-sockets-created-equal.html#post196206 .
.

 

[Les]

Actually, the old "solder blob" has/had more contact surface area than the new style.

Thanks, Derek! The old (left) lamp is exactly how I remembered them as they should be. I forgot about the brass button-thing on the bottom of some of the newer lamps. That's what I meant by "solder blob" - didn't realize it was no longer solder. I probably should have referred to it as more of a beebee.

 

[BLPisani]

derekleffew, the unglazed (gray) ones have a wider, flatter, and shorter contact post, and seem to be the older style. (Though shorter could be an optical illusion.) The glossy glazed ones have a narrower, slightly dished, taller post. (Again, possible illusion.)

One would think that the glazed type's post would suit the newer lamps better, but the one or two I have in my work pile look worse than the older ones. Generally, unless there is some major corrosion in the screw contacts on the bottom, a steel wool cleaning fixes up the older ones, but the newer ones seem to get bent posts and patina or carbonize the walls. Oh, yeah, another difference is the interior materials. The glazed have uncoated brass components, and the unglazed have "chromed" components. (I'm not sure if it's actually chrome or some other high-polish grey metal.)

I'm sure there are some other differences, but these are the ones I've noticed.

 

[ship]

Current Altman lamp sockets are as with I believe all brands of P-28s lamp sockets - Fresnel or old school radial Leko lamp socket made differently at this point. There has been a mounting screw change that don’t fit the old gear in where the screws mounting it don't match up, also an O.D. to the socket that won’t always fit inside older fixtures in being larger. This is fact in just ordered some from Altman to confirm amongst other brands of socket Bryant, Bender, Ushio etc to confirm. Other sockets that should be a direct replacement are not available any longer.

Meaning, while the lamp socket type is available from many sources, how they mount as a standard in holes to fit have changed, as with the O.D. of the socket now larger. That O.D. of the socket in some instances might become a problem in fitting in close tolarances for really old gear, otherwise, just spin the lamp socket 180 degrees, mark and re-tap the plate for the new lamp socket mounting in working again.

This for new’ replacement sockets. Beyond steel wool, I believe I have presented many times on tips and steps to refurbish old P-28s lamp sockets. Believe I have about a 90% ratio in this saving of this specific lamp base type as long as all advice is followed. We are also talking about well over a hundred of this base style I have re-surfaced in making viable again and into the hundreds of the range I have saved from... gee bad base. Than beyond that, cracked porcelain makes for parts viable to another with a good one. Made up a few viable lamp sockets by way of spare parts also.

On the lamps used, shouldn't make a difference if the lamp socket is good, spring tension is good as with the wiring - though a more point source of contact could be debated as opposed to a more plate source if the solder weld isn't more so the drect contact in that plate not mattering.

Can remember some DC bayonet bases with solder conctacts that were a problem also in that solder contact was a source of the problem. Solder literally melted away from the lamp socket in not providing a good connection. Fan or not of the beade contact, it's not persay better than plate that often isn't it also.