[amsat-bb] Re: SMA connectors

Greg D ko6th.greg at gmail.com
Thu Feb 23 20:51:50 PST 2012

Another $.02 from this neck of the woods...

BNC connectors may generally be more robust than SMA, but BNCs are not 
totally free from problems.  The center pin on my Alinco DJ-580 cracked 
away from the wire going to the PC board, and the cylinder came loose on 
its mounting (allowing it to twist), both of which required a deep dive 
through three layers of PC board for the repair.

On the other hand, I've never had a problem with the SMA connectors on 
my TH-F6A or D-7AG, which I variously use the original SMA antenna, an 
extended after-market version, or a non-supported BNC adapter with my 
Diamond RH-77B.  I am aware that SMAs wear out, so I try not to change 
them often, however.

Greg  KO6TH

Patrick STODDARD (WD9EWK/VA7EWK) wrote:
> Hi, (name/call?)!
>> My two cents worth- using an SMA to BNC adaptor does not address the
>> mechanical problem of an antenna or a coax flexing the SMA chassis connector-
>> especially the plastic HTs- I had to do a number on my VX5 which is a metal
>> case HT.
> The original two-part SMA-to-BNC adapters had no plastic/rubber
> cushions to help lessen the stress on the SMA connector.  There
> has been an adapter made by KC2BHO for some time, and now
> the Diamond adapter I referenced earlier, that have something
> to help with that.  Putting the large AL-800 telescoping whip on
> these HTs, even with the better SMA-to-BNC adapters, is probably
> not wise.
> For the typical duckie antennas, smaller telescoping whips, or
> coax - these newer adapters are adequate for most hams.  It is
> still possible to put too much stress on the SMA connector with
> this adapter and whatever is connected to the adapter.

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