I test the RF signal.
I made a 50 ohm BNC interface resistor,I used 2 100 ohm chip package resistors in parallel.and mount them inside a BNC connector.
Can this be used?
Is it different from a standard 50 ohm load resistor?
I've made similar. Mine were good up to about 1Ghz when tested for SWR with a VNA. Test yours and see.
You need a RF network analyzer: something that can check the VSWR of the load across your required frequency range.
Initially I purchased a ready made product,But its inner core is very short and slim,Looks like an inferior product.
So I disassembled it,The resistance accuracy was found to be 5%，Looks like a resistor with inductance,Would a non-inductive resistor be more effective?
So I made a new one
Currently I only have a 100M digital oscilloscope and a 20M signal generator,There are also digital multimeters and digital bridges.
Can I test them?
So I disassembled it,The resistance accuracy was found to be 5%，Looks like a resistor with inductance, Would a non-inductive resistor be more effective?
If you mean this one, it doesn't look inductive (wire wound) to me. Looks like a regular film resistor which would be OK.
Currently I only have a 100M digital oscilloscope and a 20M signal generator,There are also digital multimeters and digital bridges.
Can I test them?
If they pass a simple DC ohm check, they'll probably be fine up to 20Mhz anyway. What's the upper frequency you want to use these at?
How can I test it?
With a VNA. You may want to consiider required frequency range.
dont bother.
Mini Circuits sells fine 50 or 75 Ohm BNC/SMA terms good to 3 GHz.
SM-BM50+
EU/$10
j
I test the RF signal.
I made a 50 ohm BNC interface resistor,I used 2 100 ohm chip package resistors in parallel.and mount them inside a BNC connector.
Can this be used?
Is it different from a standard 50 ohm load resistor?
You can make it perform better by placing one of the 100 ohm resistors on the other side, so the two resistors are 180 degrees apart, on symmetrically opposite sides of the BNC center contact.
So I disassembled it,The resistance accuracy was found to be 5%，Looks like a resistor with inductance, Would a non-inductive resistor be more effective?
If you mean this one, it doesn't look inductive (wire wound) to me. Looks like a regular film resistor which would be OK.
At higher frequencies, the spiral cut in the resistive film used in through-hole metal and carbon film resistors will cause parasitic capacitance (between the spirals) and parasitic inductance (from the spiral itself) to have an effect on performance.
Usually I use 300Khz-750Khz。
Good idea, I've updated it
Looks good to go. Perfectionists would be reaching for the 200 ohm resistors and use 4, or 300 ohm and use 6, but that's diminishing returns unless you need the extra power-handling.
someone on the forum got worse performance with 4 then 2
Too much choice for the electrons, they got confused (!!)
Good idea, I've updated it
Yep, spot-on, looks great. Even cut the center contact down, that can help reduce parasitics a little at higher frequencies, nice job!
