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
Get Outlook for iOS
|
|
|
|
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
Get Outlook for iOS
|
|
|
|
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:
--
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:
|
|
|
|
Doug G4DZU
TNCs are good to at least 10G
On 28 Oct 2019, at 18:03, Gordon REASON via Groups.Io <gordonj.reason@...> wrote:
|
|
|
|
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
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
Get Outlook for iOS -- Paul Bicknell G8KFW South Coast UK
|
|
|
|
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
Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Im Auftrag von Paul Bicknell
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
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
Get Outlook for iOS
|
|
|
|
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
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 _____________________________________________________
No virus found in this message. -- 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:
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. _____________________________________________________
|
|
|
|
Think I might do the same as had some doubts about BNC’s so thanks Ed.
toggle quoted messageShow quoted text
David G4GLT
On 28 Oct 2019, at 23:36, Ed G3VPF <g3vpf@...> wrote:
|
|
|
|
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.
|
|
|
