[time-nuts] Changing WECO connectors to BNC

[Perry Sandeen]

Gents,

Wrote:< Yikes, WECO is hard to find. Anyone know a source for WECO 439A/440A connectors and adapters?  Optimist that I am, I thought they would be easy to find. Coping with an HP 3336B.

Wrote: <WECO connectors aren't hard to find

Well, neither are gold nuggets if you want to pay the price.  Milstock connectors are almost $14 each.

WECO connectors are hard to find for the average person and HP used two different sizes of WECO connectors on the same input connectors on different batches of the HP 3586B. The problem still remains that you have to use two hands when connecting or disconnecting a BNC cable as the adapter rotates.  Yuck!  I have some WECO connectors and adapters and find them a PITA to use.

I have a 3336B that I’m changing over also.  On the C model they used BNC connectors so there is probably a relatively simple way to do a change over.  Since the output of the attenuator is a BNC male going to a WECO I plan on trying a female-female bulkhead mount unit from Mouser for $3.

The other possibility is to try using a female-female barrel connector ($2) attached to the attenuator.  I have a barrel connector but haven’t had the time to try it yet.  Both connectors are 1.3 inches in length.

The big problem with WECO connectors is their length.

Changing them out on my HP 3586B SLV became a bit of a challenge.  What I did after dis-assembly was to remove the original WECO connector.  (The module is six inches square and is easy to work on.)

Using a Uni-bit I enlarged to original WECO hole to accommodate the back of the flat mounting plate BNC bulkhead adapter I had.  This is where it got a bit tricky.  The female bulkhead BNC connector I have are of slightly different lengths.  The longer one measured about 5/8 inches from the base to the end.  One has to mount it on the inside of the module do to the thinness of the plastic bezel.  So after mounting the BNC I had to use a Dremmel tool with a cutter head to remove plastic so the mounting screws would fit and allow the bezel to fit flush.

Even after that was done I had to enlarge the bezel hole with the Uni-bit so that the BNC male outer shell could lock on properly.

So far I have done two SLV’s and it has worked fine.  In the future though I’m going to try using female-female straight adapter as they give a quite a longer connection barrel than the bulkhead units.  I have three more SLV’s to convert.

I’ve gone into a lot of detail about what I did.  Don’t let that discourage you. It isn’t hard at all.  It just takes some time and patience.

One last thought.  If on the HP 3336B you change the 1K single turn frequency calibration pot to a 10 to 20 turn pot, the oscillator is much easier to calibrate right on the money 

Regards,

Perrier