On 3/28/2010 12:49 PM, Curt wrote:
I power my 540 with an SEC switching power supply rather than using a Ten
Tec 262M or 252M. This after reading about pass transistor failure issues
and retrofitting crowbar circuits it just seemed too much trouble and risk
to try using these old supplies.
The only issue I'm wondering about is turning off the rig by turning off the
supply. Of course the rig slowly dies as the PS caps bleed off. I guess
maybe the Ten Tec supplies somehow avoid this when mated with a 540. What
are other folks doing if anything to connect up to a non-Ten Tec power
supply.
The tentec supplies do nothing about that, except to put the power
switch on the volume control, so to turn the supply off you turn the
volume control so you don't hear the rig die slowly as the power supply
runs down the capacitors. Its also possible that the TenTec supplies
don't store as much energy in their filter capacitors and their output
voltage drops faster because of the high drops of the linear regulators.
What I did with my Corsair II with my station supply was to make up a
power cable with a relay. The relay coil has a diode in parallel with it
to kill inductive kicks and then I put a diode in series with the low
power line voltage rated switch in the Corsair II to make the assembly a
reverse polarity protector. I used an automotive 30 amp cube relay. The
spade lugs made assembly convenient.
73, Curt KB5JO
73, Jerry, K0CQ
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