[Milsurplus] question - on BNC RF connectors

[Al Klase]

Allow me to comment.

 From the Amphenol Website: "....Two distinct types of 75 Ω BNC's are 
available, and both mate with each other and with 50 Ω BNC's......."

http://www.amphenolrf.com/products/bnc.asp?N=0&sid=522283805AB6617F&

Google is our friend. It took about 40 seconds.

Regards,
Al


On 9/1/2013 6:21 AM, Mike Feher wrote:
> Gene -
>
> I am not sure what you are trying to say here. If there is indeed a 75 ohm
> BNC, that I am still not convinced of, then the center contact both male and
> female would be smaller in diameter than the 50 ohm versions, providing
> everything else is identical. Just like in the N connector case, as the
> impedance is determined by the outside diameter of the center conductor and
> the inside diameter of the outer conductor along with the distance between
> them and the dielectric used. As I mentioned previously, at HF frequencies,
> and even low VHF, this is not even noticeable. 73 - Mike
>
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960
>
> -----Original Message-----
> From: milsurplus-bounces at mailman.qth.net
> [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of W2HX
> Sent: Saturday, August 31, 2013 6:57 PM
> To: John Hutchins; Mike Feher
> Cc: 'Milsurplus at mailman.qth.net'
> Subject: Re: [Milsurplus] question - on BNC RF connectors
>
> The other way will not work. Plus, because the female socket is a larger
> diameter than the 50 ohm male, you will not have a good connection. Expect
> diminished working frequency range.
>
>   
> 73 Eugene W2HX
>   
>
>
> -----Original Message-----
> From: milsurplus-bounces at mailman.qth.net
> [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of John Hutchins
> Sent: Saturday, August 31, 2013 6:17 PM
> To: Mike Feher
> Cc: 'Milsurplus at mailman.qth.net'
> Subject: Re: [Milsurplus] question - on BNC RF connectors
>
> Group -
>
> With the BNC connector Panel mount Female 75 Ohm will mate with a male
> 50 Ohm RG58C/U Pamona cable  just tried this out on my work table.
> I am making up a few test fixtures, blocking capacitors, and such mounted in
> little metal boxes needed for the signal generator to meet various receiver
> alignment criteria.
> Since we are talking about ~1/2" run length at most for the 75Ohm females
> connector.  I do not think that a 50 Ohm load requirement for the signal
> generator is going to suffer, that much of a miss-match.
>
> Conclusion I have reached is that a 50 Ohm Male will mate with a 75 Ohm
> Female.
>
> Thanks for you assistance.
> Hutch
>
>
>
> On 8/31/2013 9:22 AM, Mike Feher wrote:
>> I am not sure about that. N connectors definitely have different
>> diameter male and female sections and are not interchangeable without
>> either damage, or, an open circuit. However, from what I recall, BNCs
>> are interchangeable as the only difference between the two is the
>> dielectric loading within the connector. At low frequencies, the only
>> problem if they do mate would be a
>> 1.5 to 1 impedance mismatch jump, not a big deal for most applications.
>> Regards - Mike
>>
>> Mike B. Feher, N4FS
>> 89 Arnold Blvd.
>> Howell, NJ, 07731
>> 732-886-5960
>>
>>
>> -----Original Message-----
>> From: milsurplus-bounces at mailman.qth.net
>> [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of J. Forster
>> Sent: Saturday, August 31, 2013 10:02 AM
>> To: John Hutchins
>> Cc: Milsurplus at mailman.qth.net
>> Subject: Re: [Milsurplus] question - on BNC RF connectors
>>
>> The real 50 and 75 Ohm BNCs do NOT intermate w/o damage. The center
>> connector pin is different.
>>
>> You should use what the generator has.
>>
>> -John
>>
>> ================
>>
>>
>>> Group -
>>> Have generators that are 50ohm  and 75ohm outputs respectively.
>>> Making blocking capacitor modules; and RMA ant simulator module to be
>>> used between the two different generators.  Do I use 50 Ohm BNC or 75
>>> Ohm BNC connectors? Or does it really matter.
>>> Thanks
>>> Hutch
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-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/