[ARC5] R-23/ARC-5

[Kenneth G. Gordon]

On 1 Mar 2019 at 0:59, Robert Downs via ARC5 wrote:

> The 12SG7 (equivalent to a 12BA6 except for base and envelope) might have
> helped the performance of the 10-meter conversion a little bit, but only if
> some other component values were also changed.

I did try the 12SG7 in both the RF and 1st IF stages of my 10 meter conversion and the 
result was that the background noise level was reduced, but the overall sensitivity was not 
improved.

I suppose this means that the S+N/N ratio was improved, but the antenna trimmer was no 
longer effective either.

As you say, some circuit changes would have been needed in order to make full use of the 
improved signal to noise ratio.

I didn't think the improvement was worth the effort.

And using one in the 1st IF made no improvement whatever.

I WAS somewhat surprised at just how effective the 12SK7 was at 10 meters, though.

Ken W7EKB