BNC/TNC connectors


Ed G3VPF
 

I have recently experienced two BNC connectors causing intermittent problems on the UHF IF connectors on my microwave transverters. Now considering whether to change to TNC connectors. Can anyone comment on whether TNC’s are better than BNC’s on 144/432MHz?

These transverters are used in the /P kit so the plugs get used frequently.

Ed G3VPF


KENT BRITAIN
 

The TNC connector was developed because they found that BNC's were
'noisey' in aircraft applications.    Kent G8EMY

On Monday, October 28, 2019, 11:01:03 AM CDT, Ed G3VPF <g3vpf@...> wrote:


I have recently experienced two BNC connectors causing intermittent problems on the UHF IF connectors on my microwave transverters. Now considering whether to change to TNC connectors. Can anyone comment on whether TNC’s are better than BNC’s on 144/432MHz?

These transverters are used in the /P kit so the plugs get used frequently.

Ed G3VPF


Peter G3SMT
 

Hi Ed,

I find that any of the threaded connectors to be more reliable in the field and have used TNC extensively in land and marine mobile applications.  Don't forget to use suitable strain relief and ensure that the connectors are kept clean and dry.

73

Peter  G3SMT


On 28/10/2019 16:00, Ed G3VPF wrote:
I have recently experienced two BNC connectors causing intermittent problems on the UHF IF connectors on my microwave transverters. Now considering whether to change to TNC connectors. Can anyone comment on whether TNC’s are better than BNC’s on 144/432MHz?

These transverters are used in the /P kit so the plugs get used frequently.

Ed G3VPF


--
Peter G3SMT


Gordon REASON <gordonj.reason@...>
 

BNC's for up to 50 Mhz ............ONLY

All of mine went into the bin .

On 28 October 2019 at 16:06 KENT BRITAIN <WA5VJB@...> wrote:

 
The TNC connector was developed because they found that BNC's were
'noisey' in aircraft applications.    Kent G8EMY

On Monday, October 28, 2019, 11:01:03 AM CDT, Ed G3VPF <g3vpf@...> wrote:


I have recently experienced two BNC connectors causing intermittent problems on the UHF IF connectors on my microwave transverters. Now considering whether to change to TNC connectors. Can anyone comment on whether TNC’s are better than BNC’s on 144/432MHz?

These transverters are used in the /P kit so the plugs get used frequently.

Ed G3VPF


 


 


Doug G4DZU
 


TNCs are good to at least 10G


On 28 Oct 2019, at 18:03, Gordon REASON via Groups.Io <gordonj.reason@...> wrote:

BNC's for up to 50 Mhz ............ONLY

All of mine went into the bin .

On 28 October 2019 at 16:06 KENT BRITAIN <WA5VJB@...> wrote:

 
The TNC connector was developed because they found that BNC's were
'noisey' in aircraft applications.    Kent G8EMY

On Monday, October 28, 2019, 11:01:03 AM CDT, Ed G3VPF <g3vpf@...> wrote:


I have recently experienced two BNC connectors causing intermittent problems on the UHF IF connectors on my microwave transverters. Now considering whether to change to TNC connectors. Can anyone comment on whether TNC’s are better than BNC’s on 144/432MHz?

These transverters are used in the /P kit so the plugs get used frequently.

Ed G3VPF


 


 


Paul G8KFW
 

Going back in time (30 years) we made inter digital filters for 23 cm

When I put it on the analyser to tune up it was imposable due to the flexing of the BNC connectors 

I changed them for TNC and tuning up became a simple procedure

 

An inter digital filter is probably the worst case scenario but it proved the point  

I generally prefer TNC over a BNC  for  TX or high frequency (above 700 mhz) where a N connector cannot be installed

 

Another problem you might be suffering from is that the cheep BNC connectors tend to have a sloppy outer ring that locates on the lugs

So dues not put the contacts under pressure and this causes intermittent connection  

 

Paul B

 


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of KENT BRITAIN
Sent: 28 October 2019 16:07
To: UKMicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] BNC/TNC connectors

 

The TNC connector was developed because they found that BNC's were

'noisey' in aircraft applications.    Kent G8EMY

 

On Monday, October 28, 2019, 11:01:03 AM CDT, Ed G3VPF <g3vpf@...> wrote:

 

 

I have recently experienced two BNC connectors causing intermittent problems on the UHF IF connectors on my microwave transverters. Now considering whether to change to TNC connectors. Can anyone comment on whether TNC’s are better than BNC’s on 144/432MHz?

 

These transverters are used in the /P kit so the plugs get used frequently.

 

Ed G3VPF

 


--
Paul Bicknell G8KFW   South Coast UK


DD1US
 

Hi,

 

I have some 50 ohm cables with BNC connectors, which have an additional ring which is screwed on once the BNC is attached.

 

This makes a very nice and stable connection.

 

I do not know where those are from (bought them on a fleamarket).

 

Does anyone have an idea where these connectors might be available ?

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Paul Bicknell
Gesendet: Montag, 28. Oktober 2019 22:51
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] BNC/TNC connectors

 

Going back in time (30 years) we made inter digital filters for 23 cm

When I put it on the analyser to tune up it was imposable due to the flexing of the BNC connectors 

I changed them for TNC and tuning up became a simple procedure

 

An inter digital filter is probably the worst case scenario but it proved the point  

I generally prefer TNC over a BNC  for  TX or high frequency (above 700 mhz) where a N connector cannot be installed

 

Another problem you might be suffering from is that the cheep BNC connectors tend to have a sloppy outer ring that locates on the lugs

So dues not put the contacts under pressure and this causes intermittent connection  

 

Paul B

 


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of KENT BRITAIN
Sent: 28 October 2019 16:07
To: UKMicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] BNC/TNC connectors

 

The TNC connector was developed because they found that BNC's were

'noisey' in aircraft applications.    Kent G8EMY

 

On Monday, October 28, 2019, 11:01:03 AM CDT, Ed G3VPF <g3vpf@...> wrote:

 

 

I have recently experienced two BNC connectors causing intermittent problems on the UHF IF connectors on my microwave transverters. Now considering whether to change to TNC connectors. Can anyone comment on whether TNC’s are better than BNC’s on 144/432MHz?

 

These transverters are used in the /P kit so the plugs get used frequently.

 

Ed G3VPF

 


--
Paul Bicknell G8KFW   South Coast UK


alwyn.seeds1
 

Dear Ed.,

Dare I ask the manufacturer and the part number for the BNC connectors you are using?

There are some rubbish connectors around these days.

I used MIL-PRF-39012 BNC Connectors on our contest systems and have not seen any problems in more than 5 years of regular field (literally) use.

TNCs are preferable in any environment where vibration is an issue. Again, make sure you buy good quality ones. 

The distributors, such as RS and Farnell, do sell “commercial” ie low quality ones, as well as the MIL-spec. items.

Caveat emptor,

Regards,

Alwyn
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Ed G3VPF
 

Alwyn

These are the cheap BNCs from CPC. They are a very sloppy fit when mated. Have ordered a selection of TNC connectors and will change to them.

Ed G3VPF 


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of alwyn.seeds1 <a.seeds@...>
Sent: Monday, October 28, 2019 10:08:06 PM
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] BNC/TNC connectors
 
Dear Ed.,

Dare I ask the manufacturer and the part number for the BNC connectors you are using?

There are some rubbish connectors around these days.

I used MIL-PRF-39012 BNC Connectors on our contest systems and have not seen any problems in more than 5 years of regular field (literally) use.

TNCs are preferable in any environment where vibration is an issue. Again, make sure you buy good quality ones. 

The distributors, such as RS and Farnell, do sell “commercial” ie low quality ones, as well as the MIL-spec. items.

Caveat emptor,

Regards,

Alwyn
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Paul G8KFW
 

Hi Ed my best advice for the day is you consign them to the trash can

Otherwise you will use them as you still have them and you will be back to square 1

 

I do use cheep connectors but they are used for IF frequencies below 700 mhz and that is after inspection and putting 10% - 20% in the trash bin

 

The RS brand were very good haven’t bought any from RS for over 5 years still using present stock  

But I must have ordered 1000’s used 100’s my sylph infect my first holiday job I must have put on over 50 in my 2nd week

 

Paul B

 


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Ed G3VPF
Sent: 28 October 2019 23:36
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] BNC/TNC connectors

 

Alwyn

 

These are the cheap BNCs from CPC. They are a very sloppy fit when mated. Have ordered a selection of TNC connectors and will change to them.

 

Ed G3VPF 

 


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of alwyn.seeds1 <a.seeds@...>
Sent: Monday, October 28, 2019 10:08:06 PM
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] BNC/TNC connectors

 

Dear Ed.,

 

Dare I ask the manufacturer and the part number for the BNC connectors you are using?

 

There are some rubbish connectors around these days.

 

I used MIL-PRF-39012 BNC Connectors on our contest systems and have not seen any problems in more than 5 years of regular field (literally) use.

 

TNCs are preferable in any environment where vibration is an issue. Again, make sure you buy good quality ones. 

 

The distributors, such as RS and Farnell, do sell “commercial” ie low quality ones, as well as the MIL-spec. items.

 

Caveat emptor,

 

Regards,

 

Alwyn

_____________________________________________________

 

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.

_____________________________________________________

 

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Checked by AVG - www.avg.com
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Internal Virus Database is out of date.


--
Paul Bicknell G8KFW   South Coast UK


Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
 

On Mon, 28 Oct 2019 at 19:47, Doug G4DZU via Groups.Io <doug.parker=btinternet.com@groups.io> wrote:

TNCs are good to at least 10G


On 28 Oct 2019, at 18:03, Gordon REASON via Groups.Io <gordonj.reason@...> wrote:

BNC's for up to 50 Mhz ............ONLY

All of mine went into the bin .


Maury Microwave sell a couple of VNA calibration kits with BNC connectors 


* 50 ohm 10 GHz - model 8550CK10
* 75 ohm 12 GHz - model 8580CK10

The only problems I have experienced with BNCs has been when they are incorrectly fitted - which is often the case. But I have seen this problem on SMAs, Ns and BNCs.

There are some crappy connectors around. I have a piece of leaky feeder made by Gore. It was for use on aircraft and cost a small fortune. Gore stuck some really poor connectors on them. 

I am not too impressed with Gore stuff, although Pasternack are the worst of the expensive manufacturers. 

Dave
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


alwyn.seeds1
 

Dear All,

Problem solved- bad quality connectors.

In the microwave business people often replace the last four letters of Pasternack with something less polite. 

BNCs are rated for use up to 4 GHz (1.5 GHz for 75 Ohm types). However, there is a price to be paid for the quick connect feature- risk of incomplete contact of the outer, if there is sideways pressure on the plug.
RF leakage is then poor and a suck-out in transmission performance can occur.

In equipment that does not get moved around much I would use BNCs up to 1,296 MHz. For /P equipment, not above 450 MHz.

I think that the old RS BNC connectors were made by TE Connectivity (was Greenpar), first in Harlow, later in Taiwan. Tyco have moved production of this line to China and the current types supplied to the old TE part numbers bear no resemblance to the original drawings.

I do not know where RS currently source their own brand connectors from, but careful testing would be wise.

Regards,

Alwyn

_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Dave
 

Think I might do the same as had some doubts about BNC’s so thanks Ed. 
David G4GLT 


On 28 Oct 2019, at 23:36, Ed G3VPF <g3vpf@...> wrote:


Alwyn

These are the cheap BNCs from CPC. They are a very sloppy fit when mated. Have ordered a selection of TNC connectors and will change to them.

Ed G3VPF 


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of alwyn.seeds1 <a.seeds@...>
Sent: Monday, October 28, 2019 10:08:06 PM
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] BNC/TNC connectors
 
Dear Ed.,

Dare I ask the manufacturer and the part number for the BNC connectors you are using?

There are some rubbish connectors around these days.

I used MIL-PRF-39012 BNC Connectors on our contest systems and have not seen any problems in more than 5 years of regular field (literally) use.

TNCs are preferable in any environment where vibration is an issue. Again, make sure you buy good quality ones. 

The distributors, such as RS and Farnell, do sell “commercial” ie low quality ones, as well as the MIL-spec. items.

Caveat emptor,

Regards,

Alwyn
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Leo Bodnar
 

It is safe to say that random BNC connector has higher than 50% chance of being crap.
However, there are good BNCs around.  Here is how to tell the crap ones without SA or TDR:

A single mechanical feature that makes bad Chinese BNC connectors awful is the lack of spring-loaded barbs on the barrel.
So rubbish plug connector, when mated with a jack, have two rigid metal tubes inside each other - occasionally making a single point contact.
This sometimes even breakes shield DC continuity.
Ironically, higher frequencies are not that bad as DC since there is a bit of capacitive coupling left even when DC link is broken...

Once you know this you can check connectors visually.
Another tell-tale sign is that good connector should mate with an effort.  And it should not be coming only from the centre pin.

I have just dumped a few hundred unused plugs to avoid mixups in the future....

--
Leo Bodnar / M0XER


Josh Murray
 

Thank you Leo, this is a really useful tip and definitely makes sense.

Best Regards

Josh de M0JMO

On Thu, 14 Nov 2019 at 12:30, Leo Bodnar <leo@...> wrote:
It is safe to say that random BNC connector has higher than 50% chance of being crap.
However, there are good BNCs around.  Here is how to tell the crap ones without SA or TDR:

A single mechanical feature that makes bad Chinese BNC connectors awful is the lack of spring-loaded barbs on the barrel.
So rubbish plug connector, when mated with a jack, have two rigid metal tubes inside each other - occasionally making a single point contact.
This sometimes even breakes shield DC continuity.
Ironically, higher frequencies are not that bad as DC since there is a bit of capacitive coupling left even when DC link is broken...

Once you know this you can check connectors visually.
Another tell-tale sign is that good connector should mate with an effort.  And it should not be coming only from the centre pin.

I have just dumped a few hundred unused plugs to avoid mixups in the future....

--
Leo Bodnar / M0XER