[time-nuts] HP 5370B low frequency modulation

Chuck Harris cfharris at erols.com
Sat Jul 28 15:04:13 EDT 2007

John Miles wrote:
> ); SAEximRunCond expanded to false
> Errors-To: time-nuts-bounces+cfharris=erols.com+cfharris=erols.com at febo.com
>> I have made
>> numerous shielded opens for network analyzer use by crimping an
>> SMA connector
>> nut onto a piece of copper semi-rigid shield tube without using any center
>> insulator, or center pin.
> You can (supposedly) mess up an expensive 3.5mm female connector if you mate
> it with a male SMA without a fixed center pin.  Never done this myself but
> have read about it.  I have a bad habit of using the 3.5mm-APC7 adapters
> from my cal kit for making general SMA connections to the 85046A test set,
> and I always wonder if I'm going to mess them up.

Unfortunately, the damage isn't terribly visible.  I make it a general policy
not to mate APC-3.5 with SMA, but I do the same thing with my APC-3.5 to APC7
adapters.  I haven't yet found the appropriate SMA to APC7.  I am looking to
score a couple of APC7 to N Female adapters for a reasonable price, and then
I will sin no more.

One thing to be very careful with the APC7 is to not allow the two connectors
to rotate relative to each other.  That causes the gold mating shield contact
to peen its gold into a little burr that extends into the air space between the
shield and the center conductor.  It also loses the gold on the shield contact.

-Chuck Harris

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