[ARC5] BC-453 in the SCR-274N Configuration

[Kenneth G. Gordon]

On 24 Feb 2023 at 9:43, Dave Merrill wrote:

> To find your position, don't you need a fix on the direction of two (or more) beacons?

Not necessarily. Using the so-called AN-Range, or "4-Course Range" system, not at all.
 
> And isn't a rotatable loop antenna and possibly a signal strength indicator required to do 
> that?

Again, no.

>  Or does the pilot select a beacon and turn the airplane for maximum audio and 
> note the compass reading? Seems like a clumsy solution.

The AN ranges are/were set up (as others have mentioned) so that as a pilot headed 
towards a station, he heard either an A or an N when on either side of the beacon's output, 
which merged inito a steady tone when he was headed directly towards it...or away from it.

Here is a pretty good description of it, and some history.

https://en.wikipedia.org/wiki/Low-frequency_radio_range

> The R-23A/ARC-5 did have provision for a loop antenna so I can see how that would 
> work.

Well, not ALL R-23s had the loop connections, as I remember it. In some cases (I believe the 
F4F had this) there was a loop wound around the aircraft's body just behind the pilot and 
connected to the R-23's loop connection so that the pilot could turn left and right a bit to 
determine which direction fo fly, but this method was not very effective, since most pilots 
were not correctly trained to use it, and some didn't understand it either.

It turns out that ARC made many more MF "navigation" receivers than any others and many 
were still in common use into the 1970s or later.

Ken W7EKB