This receiver has some oddball IF's like you stated. 1650 and 50 khz. With it's poor sensitivity it makes sense to start tracing the problem at the last IF and the proceed from there.
As I review episode 3 I see that there is a shorting bar between A2 and GND, That is good. But I cannot tell if both screws are down tight. If not it could mean that the A2 connection is not being made or not well.. That would seriously degrade the radio's sensitivity, particularly on Band 1 (AM), Hard to tell from my remote vantage point. Experience well learned tells one to look for this kind of stuff. This may be why he gets no signal into the grid of the RF Amp. If the problem were a snake he would have been bit a couple of times by now. It is often interesting to do an - in parallel - trouble shooting routine. When I watch a couple of the channels of those doing this kind of thing I can sometimes beat them to the solution but they are so good that they often beat me to the solution. All my best Jim (He does say he does not read the comments but sometimes I wonder)
AT 3:50 I can conclude that the first few pages of the manual have not been read/understood. It is important to know what has to be done to operate this receiver. Signal tracing at this point may be misleading. Perhaps just one simple jumper (as described) might go a long way to solve many/all the issue(s)
A man with a roadmap ( schematic) and still gets lost. Maybe breaking out the instructions for testing and operating it may be a big help. I'm sure it's on the net somewhere. This should be Video #4 Signal Tracing Frustration!
But your main problem I think is your test equipment. Maybe a Cushman CE 3,4,5 or 50. These old solid state service monitors can provide a stable rf signal from 10 khz up to I think 500 mhz. I have a Motorola R2002c as well as a couple of Cushmans.
I believe it is some kind of a bot. And poorly programmed at that too. I see this "Channel name + some random text + 'my friend'" junk posted on other radio related channels as well. What is the point of running a bot like this escapes my imagination.
