Arden Towers Flash Technology FTB-205-1A Dual High-Intensity System

WDMI and KMOJ Arden Towers, Inc. Arden Hills, MN Former Flash Technology FTB-205-1A Dual Strobe/Incandescent High-Intensity System

This is the former high-intensity system from the Arden Towers, Inc. tower which hosts WDMI and KMOJ on their Guyed Tower in Arden Hills, MN. With this tower being 625-feet tall high-intensity being now only required above 700-feet, this system was upgraded to a standard medium-intensity dual LED system with one flashhead on top, and two flashheads in the middle. I got permission to save this old system and had the strobes shipped on a pallet down here to my area. There was not an AOL strobe in this system as there was not a top antenna mast that would have extended the tower height. I also did not take any of the old incandescent beacons from the old system. Amazingly, most of the six 205-1 strobes are just about all-original on the interiors. Two strobes still have original ASM-1178 flashtubes without wires soldered on the ends and a higher-quality laced trigger wire going around the quartz envelope of the flashtube. I am uncertain if the flashtubes are original to the strobes in these two, or if the tubes in them were old stock that had been stored for years and put in during recent years.

These strobes were configured for 480V single-phase input using 1525 1.5kV transformers, so I plan on using a step-up transformer to power these strobes which is how I run the new-old-stock FTB-205-1 that is in my shop. There was not a multi-tap input transformer made for the 1.5kV 205-As or 205-1s. Not much maintenance had to be done to these strobes, besides replacing the flashtube clips in one. A few of the 205-1's do have cracked windows, but as heavy as they are that is about expected. At least the windows aren't shattered or of any danger. One 205-1 did have new boards, flashtube and trigger transformer put in it during its last year of service. I swapped those new boards out with vintage ones I had in my parts collection. To connect the strobes to the junction boxes and conduit going up and down the tower, 3/4" flexible liquid-tight conduit was used to run the power inputs, ground and also Belden 8719 16AWG sheilded cable for the control and monitor connections through the conduit. I believe Thomas & Betts Type-EF was the type of steel flexible liquid-tight conduit that was typically used by Flash Technology back then. I do plan on eventually getting some T&B gray Type-EF conduit for the strobes I plan to run to look more original.

The photos I've included with this post are three old photos from when the strobes were still on the tower in service, photos of when they were brought down to my area and also of the interior components and slight repairs that I did.

I plan to wire up the two cleanest and most original strobes out of the six to put on display. Most of the strobes still have original 2723 timing and trigger boards, but one does have a slightly later 4980 replacement, and then one had a new Skytec 24980 replacement. These strobes are very heavy at 135-pounds per strobe with the adjustable AB-2154 bracket set mounted to them. Without the accessory brackets, the 205-1 would only weight 120-pounds. I believe the strobes were mounted to the tower with SM-3954 mounts, and that mount bracket assembly weighs 62-pounds. That would make a 197-pound strobe with both attached. I did not take any of the SM-3954 mounts as that would have been a lot of extra weight and would have made the freight shipment more costly.

While finishing this post, I decided to also include a few 'bird's eye' Bing satellite imagery photos of the tower and its former 205-1 strobes to the photos. In amazing timing, one image captured the flash of all the strobes.