low MHz connector design consultant

Have you contacted companies such as Deutsch? They are the pros when it comes to mil connectors and AFAIK they do custom designs, or at least used to:

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Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

There are so many military connectors, including ones for wild environments, hermetic, etc, some standard part might work.

20 MHz isn't very demanding. Most any mil connector will be "matched" to any impedance at 20 MHz. Wavelength is 15 meters!

John

I just emailed you a contact (via PM). I'm sure Jerry can help you out.

-mpm

Am a bit confused; just because an application is special does not mean that a special connector needs to be mickey moused. Doesn't everyone absolutely *hate* it when a maker of a widget purposely with malice and forethought design something that cannot be fixed or repaired unless the user treks back to the evil maker? An RCA phono type connector is almost good enough, a BNC certainly fits.

Even a good quality 'F' or 'G' connector is good at 20 MHz, as long as the power level isn't too high. I like the 'G' series for modular designs. The male connector is just pushed onto the female connector. These are used in CATV line, trunk and bridging amplifiers, along with all the plug in filters with a VERY low failure rate.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

The connector I need goes into environments that far exceed military applications but the physical concept is similar. We have an in-house connector company that makes these connectors for us but they have never had to deal with never greater than >200KHz signals before. We tried using our regular connectors for this application and the impedance mismatch and insertion loss were extreme at 5 - 20MHz. The Zo mismatched by 50% and was not stable above 1MHz and had several resonant modes. Insertion loss something on the order is 6dB/connector and we'll have a couple dozen in series on this line. The number of series connection is the is the rub and it is unavoidable, non negotiable.

There are some commercial plastic connectors that tested very well (just to validate our test setup) with good impedance match/stability (+/- 5%) and low insertion loss (.1dB/connector) but they won't take the environment.

I'm looking for a consultant that can provide either of the following

1) model a connector that is already designed but not made (basically review the in-house company proposed design) and simulate the high frequency response of the design.

2) Give direction for the connector design based on constraints of material choices, physical size and geometry to meet the desired electrical signal characteristics while withstanding the environmental conditions.

The cut and try approach based on simple equations has a long cycle time. I'm looking to improve my chances of getting it right the first time.

On a sunny day (Thu, 29 Apr 2010 20:42:20 -0700) it happened Robert Baer wrote in :

Maybe he has size or power constaints? Humidity? Else the old Amphenol PL259...

Go you have a valid email address?

Tom

That should be "do you have an email address?" The one above bounces.

Sounds like those were filter-pin connectors. No conventional connector would behave like that at such low frequencies.

"Not stable above 1 MHz" sounds very weird. Wavelength is 300 meters!

John

. We tried using our

A PL-259 will do that, y'know.

Jim

Hell, alligator clips wouldn't be that bad at these frequencies.

Jim

RCAs work quite well up to about 100 MHz.

Jim

At 1 MHz, an ordinary wall plug and outlet has excellent specs.

John

Actually, ye olde PL-259 as well. It used to be called the shielded banana-plug. I have used these up to >100MHz and under 30MHz at over a kilowatt. Up to 100W I even used 1/4" phono plugs and the VSWR didn't move one bit.

For the PL-259 you could get very rugged ones, gold plated and with ceramic inner body. This was in my ham radio days.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

BNCs are pretty good at 6 or 7 GHz. I just did

sampling head, TDR step

8" sma coax sma-BNC male BNC female-SMA 8" sma coax other channel of head

and got a pretty decent step response with 52 ps rise time, using the cheapest Jameco sma-bnc adapters on the planet.

John

On a sunny day (Fri, 30 Apr 2010 10:00:44 -0700) it happened Joerg wrote in :

I use them today, a lot:

e.

f

fits.- Hide quoted text -

I don't know if it applies in this circumstance, but....

You do know that the FCC REQUIRES special connectors on Part-15 equipment (low-power, unlicensed) if the device has user replaceable antennas? Right? And by "special connector", it is meant types that are not commonly avaialble to consumers for purchase -- though over time, this definition has always been a moving target.

See the first paragraph of FCC Rule 15.203. Link:

e47-vol1-part15.pdf

Several years ago, the FCC released an update of what it now considers to be user available. Of course, the directive is forward-looking only, so if you're already manufacturing something that uses a connector formerlly considered "special", and is now commonplace, you are free to continue flooding the market with devices using those older connectors. In other words, this whole Part-15 notion of special connectors isn't really well thought out. (Big shocker there!).

Some manufactuers go overboard of course, and specify a connector so esoteric (perhaps unique only to them), that they will never run afoul of Part-15, even has periodic updates occur. This allows them to freely standardize on a specific connector -- which in some markets, and on some products, is an advantage in the marketplace.

-mpm

I'm a great fan of SMBs. They are small, easy to mate and unmate (no screwing around!) and are almost as good as SMAs for speed.

ftp://jjlarkin.lmi.net/DSC01786.JPG

There are tons of SMB cables on ebay, too.

John