[Milsurplus] Forest Service Northern Radio Company Type 450

[Robert Nickels]

On 6/10/2016 10:21 PM, David Stinson wrote:
> The previous owner had it marked "10 and 15 meters"
> but the coils in it sure don't look like 10 meters. 

Agree with Hue, that's definitely for the HF range, a design similar to 
AM marine radios of that same era with a two tube transmitter and solid 
state receiver and modulator.     I can't see quite how the roller 
inductor is operated, but that's a higher-grade solution than typical 
where clips were used to tap the PA and loading coils for the various 
frequencies.   Every one of these I've seen uses a 455 kHz IF so you 
should be able to plug in a crystal from the 2-4 Mhz range and jam in 
enough signal to hear it through the receiver, even though the tuned 
circuits will likely be way off.      The transmitter should tune right 
up with a 75 meter crystal, but the usable range would have to be 
determined by experiment.

Interesting to see the post lights on the panel, which are typically 
only found in avionics.   The 3/16" mic connector, size/shape, and 
overall construction  makes me wonder if this might have been intended 
for airborne HF communications - it would have been more compact than 
the usual two-piece units.

Northern Radio Corp. continued operating until well into SSB and 
synthesizer era - I have one of their later SSB radios on the air - but 
several key engineers all left Northern in the mid / late 80's and 
started SEA.   Whether Northern had failed before then or after, I'm not 
sure.    They made good quality gear and took those skills to SEA.

73, Bob W9RAN