[Elecraft] KPA500 Problems

[Mike VE3YF]

Hi:

I hope nobody gets offended as I have also posted a message on the 
Elecraft K3 Group, but I need some help in resolving this issue. I 
have searched thru the 2 groups both
here and also on Yahoo and can eliminate a few things.

- Digout1 is off.
- The top cover interlock for the KPA500 is in place and working.
- KPAK3AUX cable is working with the KPA500 and KAT500 as far as 
tuning the KAT500 and communications between the KPA500 and the K3.
- I have recycled the KPA500 off and on as well numerous band changes 
and still nothing.
- I have re-seated all the DB15 cables as still nothing

I am having problems to key the KPA500 from the K3. The KAT500 keys 
(Completes the tune cycle if required) but can't key the KPA500.

I have taken the KPAK3AUX cable from the K3 and placed it directly to 
the KPA500 and still won't key. I have moved it back to the KAT500 
and the KAT500 keys up fine. I
have placed the KPA500 - KAT500 cable back back on the KAT500 and 
KPA500 and still nothing.

On the KPA500 display, the HV is at 75.1 and when I key the K3, that 
voltage doesn't change as well when I attempt to key the amp, I get a 
current reading of 0.

At no time during my testing did I ever get a fault.

The K3 and the KPA500 are talking to each other, I can do band 
changes from the KPA500, and the K3 displays the KPA500 Status ie 
Operate or Standby

All my tests have been done into a dummy load and when I have the K3 
set at 25 watts output, I get the far left green led on the KPA500 
power and swr bar graphs being
illuminated

I have even taken the KPAK3AUX cable off the KPA500 and tried putting 
a phono cable on the PA Key jack and shorting out the connector still 
doesn't key the KPA500.

I am quite sure others have had this problem before. But I'm at a 
loss. The K3 can talk to both the KAT and KPA and the KPA can talk to the K3.

I think (???) I can rule out the KPAK3AUX Cable at this point as it 
seems to work just fine. I am thinking something inside the KPA500 
like a bad relay since the AUX Cable
and a Phono cable hooked up to the PA Key jack both have no effect. 
This is the same for all the bands.

The amp was just at Elecraft and was given a clean bill of health, it 
had TR Circuit updates, ALC and QSK Mods completed.

Any help would be greatly appreciated.




73 De Mike
VE3YF

http://www.ve3yf.com