TNT transmitter question

[Opcom]

Hello,

Here it my latest restoration, a Radio Engineering Laboratories (REL) Cat. Nr. 175-TNT (ca. 1930) ham transmitter with a RCA UX-210. 

It works...after their fashion.

73, Lou  VE3AWA

What is the single loop of wire around the large coil, connected to the microphones terminals? Is that an RF shunt type modulation for carbon mikes?

[VE3AWA]

What is the single loop of wire around the large coil, connected to the microphones terminals? Is that an RF shunt type modulation for carbon mikes?

Yes, Patrick.

First of all, I am sending this a bit blind. Not sure if what I am going to post will get through, but here goes...

Several years ago I "worked" VE3GRO experimenting with loop modulation. Using my TNT at 5 watts output and the loop/carbon mic as pictured here, Harry made a recording of my signal. DX? 21.5 miles. 73, Lou VE3AWA

 

[Opcom]

All the pictures I see, they look just fine. Thanks!