F-unit roof detail query

[ScaleCraft]

Doing some NP research, found a bunch of photos, FT through F-9, with an appliance on the roof.
No idea. Let's say on NP if you had a 4 penny plain nail, stuck it straight through the roof vertically, centerline, in front of the horns and aft of the windscreens, would be about right for 0. A units only.
I did find a photo of a D&RG F unit with something in the same place, but without the flat, round head (or so it appears).
Funny, I find NO NP models showing that.

Any ideas?

https://www.pwrs.ca/new_announcement_im ... W_5771.jpg
This maybe shows it also without the cap shown in my photo book:
http://www.railpictures.net/images/d1/2 ... 806000.jpg

[Rufus T. Firefly]

Firecracker antenna of some sort?

[ScaleCraft]

Maybe. The round cap shown in my period photos is strange. SP units and ATSF don't seem to have them.
I was also thinking air brake vent off control stand, but finding data is proving difficult.

[bob turner]

I vote for antenna. The icycle breakers are distinctive pipes. I think they all had giant cooling fans, so no need for an inefficient slipstream cooler.

[E7]

Definitely antenna. Logical placement out front of anything that would impede signals and close to where the receiver would be in the cab.

[Chris Webster]

Maybe. The round cap shown in my period photos is strange. SP units and ATSF don't seem to have them.

Antennas were a road-specific detail... and if we are to believe Details West, then SP and ATSF used Sinclair Radio antennas:
Details West RA-214 – Sinclair Radio Antenna, ATSF, SP – HO Scale

I was going to agree with the other posters and say firecracker antenna, but then I went looking for more prototype photos and came across this one:
Railpictures.net #424567
The thing atop #6013D looks more like a 'T' than a firecracker antenna.

[ScaleCraft]

Maybe. The round cap shown in my period photos is strange. SP units and ATSF don't seem to have them.

Antennas were a road-specific detail... and if we are to believe Details West, then SP and ATSF used Sinclair Radio antennas:
Details West RA-214 – Sinclair Radio Antenna, ATSF, SP – HO Scale

I was going to agree with the other posters and say firecracker antenna, but then I went looking for more prototype photos and came across this one:
Railpictures.net #424567
The thing atop #6013D looks more like a 'T' than a firecracker antenna.

That's it, except my photos have more instances from different angles, the "top" seems to be a round plate. Ground plane would have been on the bottom.

[E7]

If you want more info. you might want to try the NP Historical Society or Key Model Imports, who imported an F9 and I think an F3 and FT.

[E7]

Take note that I am totally appalled that you have become a rivet counter!