[Elecraft] K2 trouble on 160M

[NZ0T]

I do briefly see a high current message - forgot to mention tha.

Don Wilhelm-4 wrote:
> 
> Bill,
> 
> Since it misbehaves with the dummy load, you will most likely find the 
> problem in the base K2 160 meter Low Pass Filter.
> I am surprised that you do not also see Hi Curr messages.
> 
> 73,
> Don W3FPR
> 
> NZ0T wrote:
>> Thanks Don,
>>
>> The rig behaves the same into the dummy load in all configurations with
>> or
>> without the KAT100 in line, with or without the mike or paddles
>> connected,
>> with or without attached and I even tried a different coax jumper.  160
>> is
>> the only band it occurs on.  What is confounding me is that it workrd
>> fine
>> at home but not here with the exact same configuration.
>>
>>
>>
>> Don Wilhelm-4 wrote:
>>   
>>> Bill,
>>>
>>> What does that K2 do when working into a dummy load?  If it still fails, 
>>> the problem is definitely with the K2.  If it behaves, then you need to 
>>> look at your antenna system - you may be better off with a 1:1 choke 
>>> balun than your 4-1 balun.  I really don't know why hams persist in 
>>> using a 4-1 balun when driving ladder wire feeders - the 450 ohms is 
>>> only the characteristic impedance of the line and that says nothing 
>>> about the feedpoint impedance - the ladder line acts as a transmission 
>>> line transformer.  Measure the feedpoint impedance of the 450 ohm line 
>>> with an antenna analyzer (operate it on batteries) where you connect the 
>>> balun.  If the impedance is high, then use the 4-1 balun, but if it is 
>>> low a 1-1 choke balun will be a better choice.  Which balun is better 
>>> depends on the electrical length of your feedline.
>>>
>>> The K2 can behave differently in the presence of RF-in-the-shack than 
>>> your 706, so that is not a fair comparison.  Look at what you have 
>>> connected to the K2 and ask what is different - the routing of the 
>>> paddle cable?  How is the power supply cable routed? Do you have a 
>>> microphone connected?  Have you grounded the microphone jack shell on 
>>> that K2?
>>>
>>> If you have a K2 problem, ask again with details of the failure with a 
>>> dummy load.  Get it working with a dummy load before adding the extra 
>>> element of the antenna into the problem.  All we can say right now is 
>>> that your problem is either with the antenna, power supply, any cable 
>>> attached to the K2 or the K3 itself.  Which one is pure guesswork until 
>>> you reduce the number of variables.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>> NZ0T wrote:
>>>     
>>>> Now that I have my K3 at home I moved my K2/100/KAT100 to our lake
>>>> cabin. 
>>>> Last weekend it started to shut down on 160 only when transmitting over
>>>> about 70 watts.  All other bands are fine, the antenna (160M dipole fed
>>>> with
>>>> ladder line thru 4-1 balun and about 6' of coax into the cabin) is fine
>>>> and
>>>> the ground  seems fine.  It was shutting down the MFJ 4125 switching
>>>> power
>>>> supply so thinking maybe RF was getting into the supply I took the rig
>>>> home
>>>> and it worked just fine there.  Brought it back this weekend with an
>>>> Astron
>>>> linear supply and while that PS is not shutting down the rig still
>>>> wants
>>>> to. 
>>>> I have used this same setup before here with no problems and this
>>>> started
>>>> happening suddenly last weekend.  I tried the rig without the KAT100
>>>> thru
>>>> a
>>>> manual tuner and it still wants to shut down.  My Icom 706 works fine
>>>> on
>>>> 160
>>>> with the same configuration.
>>>> Ideas?
>>>>
>>>> 73,
>>>>
>>>> Bill NZ0T
>>>>   
>>>>       
>>
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