Looking to expand my streetlight collection looking for cobra heads prefer mercury vapor or hps!

Here's a detail question -- in years past, was there any consistency to how colored C7 or C9 lamps were added to new Christmas light sets at the factory? Current sets all have the same number of each color in a designated pattern and I assumed that's how it always was. I realize that most older C7 or C9 light sets only had 7 lamps, but I still figured that overall, the same number of each color was used. In other words, if you added up the number of each color lamp in a variety of sets, it would average out to be the same number of each color.

However, I came across an eBay listing for vintage lamps that said "The reason that there are uneven numbers of each color is that when these were originally sold in the 1960s and 1970s, they put 7 red, 7 blue, 5 green, 3 orange, and 3 white in each box of 25." This was in reference to Noma and Paramount C9 sets. Does this sound right? Did manufacturers favor red and blue lamps?

If that's true for boxes of 25 lamps, how were they allocated to sets of 7 or 15? Randomly?

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Going one step further, is there a particular pattern you use in your sets? Do you allocate each color equally or do you add more of one color than another? I'm sure 99.9999% of people absolutely don't care but if anyone cares, its probably someone here!

For some reason, I'm really intrigued by this!

When using SON gear for North American MV lamps, remember to remove or deactivate the ignitor otherwise you’ll ruin the starting resistor and the starting probe will be useless. That will happen on a hot restike event, that is sure to become reality if you plan on regular use.

Clear MV looks quite good lighting leafy trees in the summer. Hope you’re able to enjoy this project for many years.

I really don't think that you'll see any major difference in service life outside the normal statistical spread that applies to all HID lamps (i.e., the 24 kh rating is the point of 50 % failure in a large group of lamps; some individual lamps will last a shorter life and others will fail well after the rated life).

Looking for a reflector box for a second of third generation OV-25. Willing to trade a first generation OV-25 door. (Fits either ballasted or remote fixture.)

If interested, please PM me.

Thanks

@ Max: OK, so fortunately not worth to talk about it 

@funkybulb: What I wanted to tell is, unfortunately we don't use any 6ft 70W fluorescent tubes here. I think they are just used in the UK... But anyhow, with the 50W HPS ballast it would fit

Depends on the lamp-ballast combination. We have a near perfect match in the case of the 175 W lamp, so it should last as specified. As for the other combinations, I except that the 75 and 100 W lamps will be slightly underdriven, so these should actually last a bit longer, although the difference will be marginal. The 50 W lamp will be slightly overdriven, no by much and this may impact its service life slightly.

Just recently they built a new shopping developed near me I thought it probably would have the dreaded LEDs for lighting but no pleasantly they've got real flouro lamps not sure if they are HF or proper ballast but its nice to see  some proper lights installed

Thanks for your answers!

I am expecting just slightly less lifetime with the mentioned gear?
And yes, I forgot that 175W lamps come with E39 base, and 100W can come as well with this base. I think, an E39 bulb will fit as well into an E40 socket, if not I will order some 

Just strange these different wattages, over here we just know 50W - 80W - 125W - 250W - 400W - 700W - 1000W - and the former 2000W. And just to mention about, the highly mysterious 185W rating which monkeyface and me discovered on some ballasts around here ( https://www.lighting-gallery.net/gallery/displayimage.php?album=1602&pos=21&pid=60997 ).

But I guess it's right, for you North-American people these clear MV lamps are much easier to get!

Marc, it is possible to run US MV lamps on European systems - but first here are the specs of each lamps you listed (data from Sylvania 2004, for horizontal operation):

50W - 95V 0.60A 1650lm
75W - 133V 0.66A 2650lm
100W - 130V 0.88A 3380lm
175W - 128V 1.55A 7700lm

Now, for the ballasts (230 V / 50 Hz mains):

50W lamp requirement: ~270 Ohm - use standard 50W HPM choke (~260 Ohm)
75W lamp requirement: ~190 Ohm - use standard 50W HPS choke (~200 Ohm)
100W lamp requirement: ~150 Ohm - use standard 70W HPS choke (~160 Ohm)
175W lamp requirement: ~90 Ohm - use standard 150W HPS choke (~90 Ohm)