Yes this topic is about those BNC to banana adapters which connects a multimeter with BNC patch cords.
Like the ones found on AC/DC Hall Effect current probes, or any circuitry that uses pulses or signals.
Those adapters retail price is rather high, and it is normal for some one to think the cheap ones on eBay as the next alternative solution.
But do they work as the expensive one does?
In the low cost ones, I found three significant flaws.
1) The center female pin diameter is not made with high precision, and this leads to bad contact especially with high precision BNC male plugs with a thin center pin.
2) Also the gold paint on those cheap BNC female type adapters is there just to fool the naked eye. Usually the center pin is made from beryllium copper who haves great electrical characteristics, and also those center points are made with the highest mechanical precision.
3) The banana plugs are poor made, and their contact point and shape, offer poor stability when they are inserted in the multimeter.
The BNC to banana adapter it should stay stably in place and hold on it and the additional BNC plug and cable. I do find as genius design the modern BNC to banana adapters, with the shrouded banana ends, they do offer better mechanical support when they used with external probes.
By buying even as used two Pomona (Made in USA) with out shrouded banana ends, I did solve all the bad contact problems, and they are great for bench type work.
But for a true problem-free mobile operation with one AC/DC Hall Effect current probe, the shrouded BNC adapter is the only way to go.