Elecraft

Re: BNCs Enough!

Classic

List

Threaded

4 messages Options

Fred Townsend-2

Re: BNCs Enough!

Without sounding my horn too loudly I have servered on IEEE connector committees and been paid big bucks to solve the production line problems. Counterfet connectors is too mild a term. There is some real crap out there and your eyeballs won't be able to detect it. Things like finish and and spring tention problems can not be seen. I recall one particular connector that was causing a 2db measured loss over a prefered Kings or Amphenol connector. The imported brand X connector was available in both 50 and 75 ohm versions, both of which were unmarked. When actually measured with a TDR they both measured 62 ohms.

Folks, life is too short to mess with S T U F F like this. Do you really have to touch the wet paint or believe the sign.

73, Fred, AE6QL

-----Original Message-----

>From: Fred Jensen <[hidden email]>
>Sent: Oct 13, 2014 12:49 PM
>To: [hidden email]
>Subject: Re: [Elecraft] BNCs
>
>On 10/13/2014 10:42 AM, Sandy Blaize wrote:
>
>> There is a lot of "crap" parts available at hamfests these days! Be
>> careful what you buy!!
>
>Had cable problems with P3 when I first got it. Bob, K6XX, at Elecraft
>and who I know well called me and said [only slightly tongue-in-cheek]
>they'd send me a replacement cable ... *if* I promised to cut the old
>one in small pieces and bury it at the bottom of our trash can so it
>never could appear at a ham swap. :-) I did.
>
>If you want connectors that fit, and that work all the time, you'll need
>to totally avoid the cheap stuff. I use only Amphenol coax connectors.
>
>73,
>
>Fred K6DGW
>- Northern California Contest Club
>- CU in the 2015 Cal QSO Party 3-4 Oct 2015
>- www.cqp.org
>
>
>
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:[hidden email]
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
>Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

David Cutter

Re: BNC v TNC

Hi Fred

I wonder if you have come across counterfeit TNC connectors. I would guess
that since these are not used in the mass computer industry then there is
less incentive for the counterfeiters to be interested. The BNC is most
interesting because it's so easy to connect and disconnect, but for me it's
a size issue and I prefer the *improved* water resistance of the TNC. I
left a mated pair out in a heavy downpour recently and found no water
ingress. If I were doing it properly I would apply a little Vaseline
petroleum jelly on the thread.

David
G3UNA

> Without sounding my horn too loudly I have servered on IEEE connector
> committees and been paid big bucks to solve the production line problems.
> Counterfet connectors is too mild a term. There is some real crap out
> there and your eyeballs won't be able to detect it. Things like finish and
> and spring tention problems can not be seen. I recall one particular
> connector that was causing a 2db measured loss over a prefered Kings or
> Amphenol connector. The imported brand X connector was available in both
> 50 and 75 ohm versions, both of which were unmarked. When actually
> measured with a TDR they both measured 62 ohms.
>
> Folks, life is too short to mess with S T U F F like this. Do you really
> have to touch the wet paint or believe the sign.
>
> 73, Fred, AE6QL
>
>

kd7gc

RE: BNCs Enough!

In reply to this post by Fred Townsend-2

For what it might be worth, I only use 7/16 DIN connectors for my jumpers and transmission lines. When I have coax switches and baluns made, as well as accessories such as power meters, I always order them with 7/16 DINs. I also always buy either Andrew or Times Microwave connectors depending whether I am using hard line or coax such as LMR600 or LMR900. It costs a bunch more, but the 7/16 DIN connectors can’t be beat.

Alan/KD7GC

Alan R. Downing

Phoenix, AZ

From: Fred Townsend-2 [via Elecraft] [mailto:[hidden email]]
Sent: Monday, October 13, 2014 2:52 PM
To: kd7gc
Subject: Re: BNCs Enough!

If you reply to this email, your message will be added to the discussion below:

http://elecraft.365791.n2.nabble.com/Re-BNCs-Enough-tp7593827.html

To unsubscribe from Elecraft, click here.
NAML

David Cutter

Re: BNC v TNC

In reply to this post by David Cutter

Fred

Yes, you are right, Vaseline does run like that, but I try to stay far away
from silicon grease as it's the best adhesive-inhibitor known to man even
one molecule thick layer! I worked in a factory which banned it because of
that. I use silicon RTV (the non-acetic acid type).

We used to be advised not to plug 50 ohm coax into a scope because it was
said it would damage the 75ohm panel connector, but that must have changed
with the change of the centre pin dimension as someone said here.

David
G3UNA

----- Original Message -----
From: "Fred Townsend" <[hidden email]>
To: "David Cutter" <[hidden email]>
Sent: Tuesday, October 14, 2014 12:40 AM
Subject: Re: [Elecraft] BNC v TNC

>
> Hi David:
>
> Yes I have seen counterfeit TNCs. The assembly I worked on had two BNC,
> two TNC and one SMA. Only the SMA, which was receive only (GPS), did not
> have problems. The connectors were cast and had mold marks. Resistance was
> supposed to be a few milliohms but measured 10 times that. They were
> inferior in just about every parameter. They had no manuafacture's mark at
> all so impossible to trace beyound the Chinise distributer we bought them
> from.
> Vaseline is good but will run a bit in hot sun. (Is that a problem in the
> UK?) I use a silicon grease from 3M. It was listed as stopcock grease but
> worked perfect at all temps. I like a silicon rubber tape or RTV (type 1)
> for wrapping. RTV has the nice advantage it can be applied around water
> without drying.
>
> 73
> Fred
>
> -----Original Message-----
>>From: David Cutter <[hidden email]>
>>Sent: Oct 13, 2014 4:14 PM
>>To: Fred Townsend <[hidden email]>, [hidden email]
>>Subject: Re: [Elecraft] BNC v TNC
>>
>>Hi Fred
>>
>>I wonder if you have come across counterfeit TNC connectors. I would
>>guess
>>that since these are not used in the mass computer industry then there is
>>less incentive for the counterfeiters to be interested. The BNC is most
>>interesting because it's so easy to connect and disconnect, but for me
>>it's
>>a size issue and I prefer the *improved* water resistance of the TNC. I
>>left a mated pair out in a heavy downpour recently and found no water
>>ingress. If I were doing it properly I would apply a little Vaseline
>>petroleum jelly on the thread.
>>
>>David
>>G3UNA
>>
>>
>>
>>
>>> Without sounding my horn too loudly I have servered on IEEE connector
>>> committees and been paid big bucks to solve the production line
>>> problems.
>>> Counterfet connectors is too mild a term. There is some real crap out
>>> there and your eyeballs won't be able to detect it. Things like finish
>>> and
>>> and spring tention problems can not be seen. I recall one particular
>>> connector that was causing a 2db measured loss over a prefered Kings or
>>> Amphenol connector. The imported brand X connector was available in both
>>> 50 and 75 ohm versions, both of which were unmarked. When actually
>>> measured with a TDR they both measured 62 ohms.
>>>
>>> Folks, life is too short to mess with S T U F F like this. Do you really
>>> have to touch the wet paint or believe the sign.
>>>
>>> 73, Fred, AE6QL
>>>
>>>
>