TNC jack limits

[Jamie]

Looking to select a common coax plug and jack to use, i am leaning
towards the TNC style.

Most specs I've found do not give an extra cut of freq for low
reflection effects.

Was looking at the APC 7 line, but I think that is just a little
to expensive for what ai have in mind, plus its operation is far more
than I need.

Will the TNC connector operate up to 3GHz with no problem?

Jamie

 

[Jeroen]

Looking to select a common coax plug and jack to use, i am leaning
towards the TNC style.

Most specs I've found do not give an extra cut of freq for low
reflection effects.

Was looking at the APC 7 line, but I think that is just a little
to expensive for what ai have in mind, plus its operation is far more
than I need.

Will the TNC connector operate up to 3GHz with no problem?

I suppose that depends on your definition of 'problem'.
What are the requirements? Give us some numbers!

(The simple observation that you compared TNC to APC7 is
funny in itself. These aren't at all in the same league!)

Jeroen Belleman

 

[Jamie]

I suppose that depends on your definition of 'problem'.
What are the requirements? Give us some numbers!

(The simple observation that you compared TNC to APC7 is
funny in itself. These aren't at all in the same league!)

Jeroen Belleman

Yes I know that, but I was in the shopping around mood..

There will be no transmission line between connector and device,
in other words, there will be a jack on the panel and a hand held
device that will have the other mating plug. This device is light weight.

The problem arises with the frequency that is passing through the
connector.

I have a set of APC 7's and I know those will work fine, however, I am
at home and doing this for one of my own little R&D projects and all I
have here is a 2GHZ source, which seems to work fine with a TNC
connector, but I am interested in 3Ghz.

I also have some sma connectors with PTFE, but ideally I want a
male panel mount with a knurled fitting. A quick look does not
reveal much in that line, all nuts. Maybe they are concerned with the
seating of these things. Which is one reason why I was dropping back
a bit.

Jamie

 

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BNC is OK at 3 GHz. SMB is better, 6 or so. SMA is good to 30+.

BNC are OK for test leads with frequent connect/disconnect cycles at
frequencies below 1 GHz, however, after several connect/disconnect
cycles, the shield connection tends to be quite reliable.

TNCs are rare and probably expensive. The others that I mentioned are cheap and
come in all sorts of versions, like PCB edge launch.

The TNCs have a reliable shield connection even after several
connect/disconnect cycles.

The question of N vs. BNC/TNC vs. SMA/SMB also has to do with power
levels (mW/kW) and how thick coaxial cables you intend to use.

 

[Jamie]

I dimly recall the TNC being "good" to above 3GHz.

See if you can find manufacturer's data sheets for specific connectors --
sometimes there'll be Smith charts of all the various reflection and
transmission components, which is what you want to see. Then, if you
want to be sure use that specific connector with their specific
recommended cable and connection method...

Well you see that is the problem, anything over 2 Ghz, it depends on
the dielectric material, the one's I have use PTFE.

But the short of it is, there will be no transmission line, it'll be a
miniature device with a male panel mount connector hanging off the female
connector on the main panel. There will be a small amount of DC in there
to power the external device.

Jamie

 

[Jasen Betts]

I have a set of APC 7's and I know those will work fine, however, I am
at home and doing this for one of my own little R&D projects and all I
have here is a 2GHZ source, which seems to work fine with a TNC
connector, but I am interested in 3Ghz.

RP-TNC is used for wifi antennas, so TNC should work ok.

 

[Jamie]

RP-TNC is used for wifi antennas, so TNC should work ok.

Thanks, I put a TNC Male and female together today and did a test on the
equipment at work, it looked good at 3ghz, but just as I got to ~ 3.4Ghz
I started to see changes.. So it's borderline but seems to be ok for
what I have in mind..

Thanks.

Jamie