[TenTec] Cautionary Tale: Orion 13.8 V connector (long)
w9ac at arrl.net
Tue May 29 17:38:07 EDT 2007
> My current Omni 6, I pulled out the dc cable connector and installed
a pig tail with a much stouter dc connector...30 amp power poles.
As a pig-tail, this is probably fine. However, I have measured as much as ~
0.3 VDC dropped across properly crimped, standard-sized Anderson PP
connectors under 12VDC/20A loads. In some instances, the very act of
crimping will bend the contact surface such that it is no longer in-line
with the barrel. The result is that the contacts may not mate evenly.
After each crimp, I check for barrel-to-contact alignment. It's really a
shame that such extraordinary measures are required to properly seat the APP
and keep them mated.
I cannot imagine the APP connector being used directly on the rear panel of
a transceiver, although one manufacturer is about to release a 100W rig in
July with APP panel connectors. Since heavy gauge wire is generally used
for powering, the slightest movement of the radio may be enough to slightly
unseat the connector and that's something you don't want to see at 20A while
transmitting. Since the APP is a non-locking device, I've seen them weld
together while they are inadvertently flexed under high-current conditions.
A APP connector that appears to behave fine, may be on the ragged-edge of
acceptable conductivity. The way to know for sure is to measure the voltage
drop across the connector under full load.
While at Dayton, I noticed that the folks at DCPwr.com had a nice power
distribution panel with 80-amp APP connectors. While we do not need 80-amp
connectors for the 100W class of radios, I find that the high capacity APP
connectors offer much better mechanical rigidity than the junior sizes.
Personally, I would be perfectly happy with insulated, quarter-inch brass
bolts placed on the back of the transceiver, allowing the owner to connect
directly from the bolts to the power supply, or as you have done to your
Omni Six, add the connector of your choice as an in-line pig-tail.
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