[Elecraft] K4 observation

[a******@sbcglobal]

Wait, it’s been determined that the K4 definitely has a pin one problem?

Al  W6LX/4



> On Jun 21, 2021, at 11:08 AM, David Gilbert <ab7echo at gmail.com> wrote:
> 
> 
> Does any of that mitigate the Pin 1 problem that K9YC keeps pointing out?  At first glance it doesn't appear to me that it would.
> 
> Dave   AB7E
> 
> 
> 
>> On 6/18/2021 7:33 PM, Wayne Burdick wrote:
>> John,
>> 
>> If the K4 is *off*, then there's no active circuitry involved. However, the headphone plug-insertion detect circuit may involve an IC downstream that could include a schottky diode junction -- a potential way a very strong signal could be rectified right at the radio end of the cable. We're looking at that.
>> 
>> If the cable is not very well shielded, and the TV station is *very strong*, I can imagine modern physics just barely covering this situation. It would help if the headphone cable was about the length of an end-fed dipole at the station's frequency.
>> 
>> As for the K4 chassis itself: It's very well sealed (far better than the K3/K3S).
>> 
>> Wayne
>> N6KR
>> 
>> 
>> 
>>>> On Jun 18, 2021, at 3:36 PM, John Harper <johnae5x at gmail.com> wrote:
>>> 
>>> https://www.youtube.com/watch?v=u1XRaNpgQDI
>>> 
>>> John AE5X
>>> https://ae5x.blogspot.com
>>> 
>>>> Noticed that when the antenna are disconnected, and the K4 turned off, I hear a local TV station in the headphones… Never happened on the K3.
>>> ______________________________________________________________
>> 
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