Binding post / banana jack frequency range

[bjcuizon]

Hi, does anybody know the maximum frequency of binding posts? I've noticed that some ancient rf test equipment use binding posts, but I don't know what's its max frequency. Thanks

[janoc]

Well, I would say that the ancient gear likely doesn't go anywhere above 1MHz. Once you start to care about controlled impedance, reflections and similar issues, then banana jacks are useless, regardless of frequency. That said, they will certainly conduct signal up to few GHz, but you will not have any idea about losses, and distortion due to reflections.

[PA0PBZ]

Well, I would say that the ancient gear likely doesn't go anywhere above 1MHz. Once you start to care about controlled impedance, reflections and similar issues, then banana jacks are useless, regardless of frequency. That said, they will certainly conduct signal up to few GHz, but you will not have any idea about losses, and distortion due to reflections.

Exactly, define "Maximum Frequency"... I'm sure that whatever frequency you put in there will be some output, but it will depend on humidity, windspeed, number of people nearby and moon phase.

[ChristofferB]

 I guess you Could get kinda control over impedance if you had two banana plugs with known distance between, and used ladder-line as cable, but its peobably easier replacing them with some bnc's

[bjcuizon]

Yeah, ladder line could be okay... The standard binding post spacing is 19mm or 3/4" anyway.
Thanks for all your replies guys.

[timb]

FWIW, I designed a power amplifier that does 30Vpp/10A at up to 1MHz. It has standard banana jacks for the outputs and it seems to work without much distortion or reflections (with high quality, short test leads twisted together, anyway).

At lower power levels it can be pushed up to 10MHz, however you get crazy reflections if your waveform is a squarewave (naturally) but sinewaves still come out alright for the most part (with a bit of distortion due to the slew rate limits of this particular amplifier design).

[Z80]

Nothing wrong with banana jacks, they are quite common for balanced line or high impedance outputs.

[cdev]

 There is a program called "atlc" which lets you calculate the impedance of a transmission line using a bitmap of a cross section of it, somehow. Ive never used it but it looks fairly easy to use. The plastic on the banana plugs would likely impact the match a bit - more and more as the frequency rose.. But hefty good quality banana plugs might be a quite good interconnect for balanced HF applications if the spacing and size remained consistent.

Look at high end antenna tuners, good quality binding posts and banana plugs sound like a quite reasonable way to connect up your balanced antenna.

My guess is paired banana plugs probably come out as having a fairly high impedance.. like 450 ohm ladder line, twinlead, etc.