[ARC5] Re: [Milsurplus] Hosstraders Fall 2005 hamfest report (Long)

[J. Forster]

Mike,

I posted the original question about the differences between the 13 and 13A. I'd intended the question as more of an inquiry about the relative features and performance of the 13A compared to the 13. I know there were changes made to the external antenna coupler and related things, but is the 13A distinctly better? If so, how and why? What is the rational for the changes made in the 13A?

Thanks,
-John



Mike Morrow wrote:

> Nope.  No relation at all.
>
> As I posted last week, the USAAF/USAF T-47A/ART-13 has a vernier scale on VFO dial B that allows setting it in tenths of a division, and a power interlock switch that activates when the top cover is removed.  The USN T-47/ART-13 or ATC do not have these easily observable characteristics.  Plus, an T-47A/ART-13 will say that on the nomenclature tag on the right side, which is usually in a typical Army Signal Corp layout that normally includes British unit nomenclature on it too.  The T-47A uses a different calibration book than the T-47 does.
>
> The LF oscillator that should be in a T-47A/ART-13 is the O-17/ART-13A, which only covers 200 to 600 kc in three bands.  The LF oscillator that should be in a T-47/ART-13 is the O-16/ART-13, which covers 200 to 1500 kc in six bands.  Thus the number of positions on the band switch of the LF oscillator is a dead give-away to which LF oscillator is installed, even when seen from across the room.
>
> Mike / KK5F