[Elecraft] K3 Receive Attenuation with KPA500 in Operate

[Don Wilhelm]

Brian,

I have heard this before, and as I recall it has to do with the DB15 
cable and the PTT cable when used together.

Are you using the PTT cable in addition to the cable from the K3 ACC 
cable?  If so, pin 10 of the cable should not be included.  See the note 
on page 8 of the KAT500 manual.

Normally you would not have to use the PTT cable with the K3.  See pages 
3 and 4 of the KAT500 manual.  For this arrangement, piin 10 of the ACC 
cable must be present.

If you have other devices that need access ti the K3 Key Out line, you 
would use the PTT cable AND use the key line interrupter to disconnect 
pin 10 from the DB15 Interface cable without the need for removing pin 10. .

73,
Don W3FPR

On 8/1/2013 4:30 PM, Brian F. Wruble wrote:
> Hi all:
>
> I am running a newly assembled "K-Line" --- K3/100, KPA500 and KAT500.  The
> K3 is pretty "loaded" with KRX3, KAT3, KXV3A, etc.
>
> I just noticed that received signals are down 4 S-units when the KPA500 is
> in Operate.  In Standby, signals pop right up.
>
> Reading past reflector emails on the topic, I found one thread that
> suggested this may have to do with the state of the KPA500 PTT.  I found
> that pulling the PTT RCA plug out ended the problem.
>
> Then I replaced the PTT plug, and still had no problem.  However, once I
> actually transmitted, and the PTT acted to key the KPA500, the problem
> recurred >>> Low sigs when the amp is in Operate, Full sigs when in Standby.
>
>