[Elecraft] KXPA100 firmware testers needed; much improved operation with QRO antenna tuners

[Wayne Burdick]

Hi all,

We have a new field-test release of KXPA100 firmware that doesn't fault when used at 15-20 W with external high-power antenna tuners. A typical station might have a KXPA100 feeding a KPA500 (or other high-power amp), followed by a KAT500 (or other high-power antenna tuner). 

With older firmware, running the KXPA100 at even low power into an ATU could result in very quick faults, dropping the amp into bypass mode. Some KX3 users had to exit PA MODE or set power to 10 W. (This is less than the optimal power level for tuning up a KAT500, besides being inconvenient.)

The new firmware lets you set power to 15-20 W and safely complete the antenna-tuning process into virtually any load. In many cases higher power can be used--perhaps 30 W in moderate-SWR situations typical of in-band retunes. So, overall, the operating experience with the KXPA100 in your system should be greatly improved. The amp's attenuator will still drop in when the SWR is too high, flashing the associated LED. But assuming the tuning process terminates in a low SWR, the attenuator will then then be taken back out.

This is a significant change to the KXPA100's firmware, so we'll need to do a lot of testing.

If you've experienced excessive faulting with your KXPA100 and a following tuner or amp/tuner combination, and you'd like to give this new release a try, please email me directly.

73,
Wayne
N6KR