[Elecraft] K2 K2/100 post FD review

[Mike Kopacki]

Yep I’m familiar with that formula. 

One of the tests in the assembly instructions was to test the current draw at 100w. It was 13A. The acceptable range was 13-18A so I thought that was a good result. 

Thanks,
Mike NJ2OM 

> On Jun 30, 2020, at 11:20 PM, Nr4c <nr4c at widomaker.com> wrote:
> 
> Watts is Volts X Amps. 
> Fewer Volts means more Amps. More Amps means more work for power supply, leading to fewer Volts.  Fewer Volts means ...( you get the picture). 
> 
> Sent from my iPhone
> ...nr4c. bill
> 
> 
>> On Jun 30, 2020, at 8:37 PM, Mike Kopacki <mikekopacki at gmail.com> wrote:
>> 
>> I didn’t have ring connectors big enough but I did have spade connectors. I crimped and soldered them but there was no change in the voltage readings during receive and transmit. 
>> 
>> Is it possible that the power supply is failing?
>> 
>> Why, if the voltage drops during transmit to 11.6V, does the radio still put out 100W on 30, 40 and 80 meters?
>> 
>> Thanks,
>> Mike NJ2OM 
>> 
>>>> On Jun 30, 2020, at 6:55 PM, Don Wilhelm <donwilh at embarqmail.com> wrote:
>>> 
>>> Mike,
>>> 
>>> The red and black assembly is an Anderson Power Pole connector - commonly called APP.
>>> 
>>> For the small receive current drawn, the voltage drop in the wire and connectors should be close to zero, so the 0.2 volts is significant for #12 wire unless there is something not properly tightened on the connectors.  The drop will be more substantial with the increased current during transmit at 100 watts.
>>> 
>>> Banana plugs and jacks can be used to carry a heavy current, but some of the ones I have seen have a poor contact method of fastening the wire to the banana plugs - properly installed wires on banana plugs are good for up to 30 to 50 amps.  Is there any way you can connect ring terminals onto those power supply terminals?  Like removing the outer nuts from the terminals - if so then switch to the ring terminals.
>>> 
>>> 73,
>>> Don W3FPR
>>> 
>>>>> On 6/30/2020 6:21 PM, Mike Kopacki wrote:
>>>> 
>>>> Don, don’t know what you mean by the APP assembly.
>>>> 
>>>> I can only see one metal part on the inside of the red and black connectors that plug into the K2.  I assume that is the “contact blade”?  I see nothing else on the inside.
>>>> 
>>>> But here is a possible problem, that I will throw out, knowing full well that some will think I am not very smart…..I had to buy banana plugs to make the power cable, which is part of the KPA-100 assembly instructions. When I received them from MFJ, model MFJ-7713, it was a solderless type that I had never seen before.  I talked to three people at MFJ, none could explain how the wire attached to the plug.  The third guy hung up on me.
>>>> 
>>>> So I connected the wire to the plug the only way I could see, but the configuration of the plug still eludes me.
>>>> 
>>>> The P/S output is 13.6V.  I’m seeing 13.1V at the K2.  If the normal drop is .3V, it should read 13.3V at t