Locotrol Antenna Stand

What does it look like? I know seller "brassmonger" on da bay has some modern parts listed for sale.

Does it look like a regular sinclair antenna?

I think the Brassmonger parts are PTC antenna arrays.  But I'm also curious what Locotrol stands look.

They were used by a number of companies I believe back in the 80's & 90's for mid train helpers in order that they could be remote controlled (no crew). My points of reference back then were the SP but you can also see them on ATSF locos. I am currently modelling around the time of the proposed SPSF merger and I would like to replicate this unit. The Locotrol stand is the structure behind the cab air-conditioning unit. 

Cheers

Nick

Nick,

The photo of 2858 illustrates a locomotive with a "proper" ground plane for an antenna -- and judging from the length of the antenna, it's for the VHF voice radio.  I believe ATSF would have used UHF frequencies [ probably a pair in the 450 MHz range ] for RCE [ ATSF-speak ] operation;  these would have used separate, shorter antennae.

I didn't think any ATSF 35's were equipped with Locotrol, from memory.  If so,  you can use a standard "Sinclair" / hockey skate voice antenna mounted on a square of flat plastic with standoffs to model this unit.

Best regards, SZ

If you scroll down the bottom photo in the first post in the link below, you will see the GE Locotrol antennas (the two small raised platforms behind the air conditioner at the back of the cab).  The Sinclair crew radio antenna is on the larger platform (ground plane) in the blue section above the small bump in the roof for the traction motor dust collector.   Locotrol required more space to house the remote control equipment; hence the nose length was extended several inches to make room.  One of the few locomotive models at the time that could tolerate a longer nose length was the SD40-2 (SD40T-2 for SP/DRGW) due to the spare space at either end of the locomotive (long platforms).  These models with the elongated nose were dubbed “snoot nose” locomotives.  

 http://dieseldetailer.proboard...988/atsf-sd40-2-5024

 Scott K.

Austin, TX

Check in with OGR member Teejmeister.  I think he fabricated one of these stands for a recent build of his.  Or search through his posts.  I think it was on an sd35.

Jim

Thanks for that guys

Cheers Nick

Nick, I forgot to mention the other day that Atlas has an antenna base for their gp60's.  There are two parts listed in their online catalog, although only one of them shows up on the exploded parts diagram.  Both parts are listed as "in stock".

Atlas gp60 exploded diagram

Sku 125172 cab top part 2 (called "piping" on the diagram)

Sku 125174 Antenna base (not shown on the diagram) - I'm 99% sure this is the type of stand you are looking for.

You can see an example of of what I'm presuming is the antenna base here, over the inertial filter hatch.  A google image search shows it appearing on at least the ATSF, Cotton Belt, and EMD Demonstrator models.  That being said, you could probably fabricate a base pretty quickly with styrene or brass sheet.

The part I want is the air conditioner, not currently listed in the online catalog.  I should call to check on it.

Jim

Nick,

As I think SZ is asking above, are you sure you need to model Locotrol hardware rather than voice and other radio equipment? My sense is that actual Locotrol hardware varied from road to road and even model to model. For example, the Locotrol-equipped ATSF C30-7s had a single equipment box on top behind the cab with small antennas. The snoot nose SD40-2s that Scott Kay shows used small antennas on small ground planes. I'm not sure about SP, so I suggest doing a search and trying to find some prototype photos to see what's on top.

Antenna ground planes are pretty easy to model using sheet styrene and brass wire. Sinclair type antennas are available in both plastic and brass from Precision Scale (as are roof top air conditioners). The ground plane here is fabricated, the Sinclair antenna is a PSC part, the small antenna and base a modified Atlas GP 60 part and the air conditioner an Atlas part. By the late 80s, early 90s, most ATSF models had the small antenna and ground plane, but it was for EOT purposes, not Locotrol. The small antenna and ground plane can be fabricated as well using styrene or brass sheet and wire.

RM

Nick,

I looked in my slides to see if I had a top view of 2858.  I don't, but here are some other photos that might prove of value:

The first photo with 2867 shows the [ voice ] antenna, plus exhaust deflectors.  As a bonus there is the roof of a B23, and a high cube company service box car.

The second photo, 2831, has the EOT antenna, and no strobe;  but it was taken in 10/91, all the others are from 5/87.

The third photo, 2842, has exhaust deflectors plus a snow shield.

Finally, a SF30 as an RCE receiver with the two antennae to either side of the voice antenna.

Hope these give you some references and ideas.

With best regards, SZ