[Elecraft] KAT-500 Unreliable Tuning

[Bill Frantz]

I had a similar problem during last weekend's ARRL DX SSB 
contest. I would press tune on my K3 and the K3 would come to a 
good solution using about 5W. Then I tried to transmit at 100W 
and the SWR went wonky and the power folded back. I traced it to 
a bad connection between the two sections of coax feeding the 
antenna. Testing with a dummy load can help narrow the problem 
down to antenna or other.

73 Bill AE6JV

On 3/8/21 at 10:42 AM, daveingeb at comcast.net wrote:

>Over the past six months my KAT500 autotune function has 
>deteriorated to the point where I am getting frustrated. The 
>KAT tuner is connected to a G5RV via 75' of  RG-8 coax and is 
>fed from a KPA-500 which is fed from a Kenwood TS480. I switch 
>between between barefoot and amplified transmissions. Upon 
>application of a  40 watt tune, the tuner appears to find a 
>suitable solution but when the power is raised to over 100W, 
>the amplifier faults to a high SWR, some bands, but not always 
>repeatable. The antenna and feedline have been inspected and 
>all OK. If I change bands sometimes it works at higher powers 
>and sometimes not. Other times it cannot find a solution on 
>some bands and other bands are OK, low power or amplified. If I 
>cycle the power to the KAT500, it is OK for a while and then it 
>has trouble again. The problem appears intermittent. Wondering 
>if anyone has had this same problem. Thanks de dave WB7ELY
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