[ARC5] R-23/ARC-5

[Kenneth G. Gordon]

On 28 Feb 2019 at 20:01, Mike Morrow wrote:

>     current balancing resistor.  However, there should 
>     have been little motivation for increased RF stage 
>     gain in an R-23.

This is absolutely correct. My rebuilt BC-453B can "hear" a 0.1 microvolt CW signal with all 
stock original tubes.

https://www.youtube.com/watch?v=vlz83QXM66A

I also have a BC-454 which someone attempted to modify, back in the 1950s, to cover 10 
meters. After I did some work on it to finish the original owner's project, with the original 
12SK7 RF amp, it easily copies a 1 microvolt CW signal.

I can think of no good reason to change the RF amp to any other tube.

Ken W7EKB