[Boatanchors] Receiver Amplifier Test Question

[whitebear1122 at comcast.net]

I have a test question that I hope you can shed some light on.  

 

On my HBR-13 receiver, the RF amplifier stage is a 6AZ8.  With a clearly
visible signal going into the tube, I am unable to see an output signal on
the plate of the 6AZ8.  I know the stage is working because I look at the
signal further down in the 1610 KC IF stages.  When I adjust the RF gain
control, it adjusts.  

 

What is puzzling to me is that I cannot see the signal at the output of the
6AZ8 or on the other side of the 1st mixer coil L2A.  What I did here was
pull the 1st oscillator so I was only looking at the output of the 6AZ8 as
it goes into the grid of the first mixer.  Is the oscilloscope probe loading
the output?  I'm using a divide by 10 Tek scope probe and a Tek 2213 scope.
What the heck am I doing wrong?

 

I've included a link to a photo of the this RF stage schematic.  HBR-13 RF
Amplifier Schematic <https://i.postimg.cc/VNvH9bPT/IMG-2797.jpg> 

Here is a link to a few photos of the HBR-13.  Scott's HBR-13
<https://postimg.cc/gallery/y7qmvfV> 

 

Thanks.  73, Scott WA9WFA