[Elecraft] K3 Receive Attenuation with KPA500 in Operate

[Brian F. Wruble]

Hi Don,

Thanks for the prompt response.

Yes, I am using the DB15 and the PTT line.  I got it working.  Here is my
new cable lineup:




1.  ACC on K3 (DB15) >>> DB15 Y Cable | >>>DB15 Cable >>> "XCVR" (DB15) On
KAT500
                                                                  |
                                                      And      | >>> "ACC"
on Navigator Interface


2.  "RS232" on K3 >>> "XCVR" (RS232) on P3


3.  "PC" on P3 >>> "RS232" on Navigator Interface


4.  "AMP" on KAT500 (DB15) >>> DB15 Cable >>> "AUX1" (DB15) on KPA500

5.  NO PTT LINE into KPA500 or into KAT500

6. No "Key Line Interupter" anyplace.


With this lineup, is the KAT500 protected from the KPA500 keying when the
KAT500 is tuning?

I must admit, I have mightily confused myself in this process.

Thanks again,

Brian W3BW



*Brian F. Wruble, C.F.A.

*70 is the new 40.*
*
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On Thu, Aug 1, 2013 at 5:01 PM, Don Wilhelm <w3fpr at embarqmail.com> wrote:

> 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.
>>
>>
>>
>