[Elecraft] KPA1500 hum - problem solved

[Bob McGraw K4TAX]

If it was a switch in line to the vertical, I’d think you would observe a SWR increase when that antenna was selected. 

Bob, K4TAX


Sent from my iPhone

> On Apr 5, 2020, at 5:12 PM, Carl Yaffey <cyaffey at gmail.com> wrote:
> 
> It turned out to be using the 4-position Alpha-Delta coax switch. No problem until I connect both the vertical and the dipole to it. 
> 
>> On Apr 5, 2020, at 5:37 PM, Buck <radiok4ia at gmail.com> wrote:
>> 
>> I would bet your coax shield is acting like a radial and bringing RF back into the shack.  Need a choke.
>> 
> 
> Carl Yaffey  K8NU
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