[Collins] 51J4 panadapter tap?

[Eugene Hertz]

Hello all, 

Recently acquired a Panoramic SB-15a panadapter (ultrasonic spectrum analyzer) that covers ranges of <100khz to >500khz which is (in theory) great so I can use it for both my 455khz radios and my 51J4. Sweep width is 0-200Khz. It has a nice large 5" scope!

I was wondering if anyone has an opinion of the best way to tap the 51J4 for the widest bandwidth and least loading etc., etc.? One gentleman I located offered the following, and I was wondering if anyone had any opinion or different solution. 

The suggestion was to connected it to the plate of V106 through a series combination of a 0.001uf/630V cap and a 47K resistor 
into RG-58 coax. According to the gentleman, this minimizes loading and did not require retuning of the first IF transformer T101. He also noted that bandwidth was 40-100khz at that point, which is probably pretty darn good. 

Any other opinions? Contrary or supporting? Any thoughts about the series cap and resistor values? I am not completely sure of the input impedence of the analyzer other than to say at DC with the unit on but unplugged, I measured infinite ohms on my flue 8840a/af. Would there be any benefit/disadvantage to tap after T101 but before the crystal filters? 

Options? Ideas?
thanks
Eugene