[Elecraft] Power Cord Questions

[WILLIS COOKE]

My answers will be different from some you have seen.
1.  I would not use any fuses.  The RM35M has a current limiter circuit and a line fuse to protect it.  The K3 has a circuit breaker to protect it. If you are installing a transceiver in a car, you need a fuse in the positive to protect against a wire short and you need a fuse in the negative to protect you from a loose battery ground that routes your starter current through your transceiver ground.

2.  The power cord should be at least #10 and as short as reasonable.  6 feet is fine!  Much more than 10 feet and you might consider 2 #12 or #8.

3.  I would not use a fuse unless I was using a home made supply with no limiter or a battery for power.  If Elecraft thought you needed a fuse they would have given you one.
 
Willis 'Cookie' Cooke 
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart


________________________________
 From: Lee Buller <k0wa at swbell.net>
To: Elecraft Reflector <elecraft at mailman.qth.net> 
Sent: Friday, March 9, 2012 8:37 PM
Subject: [Elecraft] Power Cord Questions
 

I am rebuilding the power cord from my RM35M to the K3.

Questions.....

1.  Do you need fuses to be in both the positive and negative lead?  Or, since I 
am a "fixed" station, can I get away with one fuse in the positive lead?  
Currently, I have both leads fused.

2.  What length should the power cord be....considering that there will be some 
power consumption (voltage drop) in the line which is longer than shorter?  My 
current length is over 6 feet.

3.  Should the fuse(s) be mounted at the radio or at the power supply?  
Currently, mine are right at the power supply.

The reason why I am rebuilding the power cord is that I am getting somewhat of a 
voltage drop on key down.  According to the K3, the voltage is at 13.8 but goes 
to 11 volts at key down at 100 watts....around 21 to 22 amps.  So, I suspect 
something might a tad glitchy in the power cord.  Maybe I just need to reinstall 
the Anderson Power Poles.

Comments?

Lee - K0WA




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have any Common Sense - get some Common Sense and use it.  If you can't find any 
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-  John W. (Kansas)

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