K2 Survives (apparently) the “Alpha Brick-on-the-Key” Test

You have probably seen that advertisement in the Ham magazines, where the Alpha Amp’s toughness is shown by a brick on a hand key. Well I did something close to that this weekend with my K2, by accident of course. I was getting a RTTY setup ready for the upcoming VAQP Contest. Everything was setup and I had made a couple of Test QSOs. Then I walked out of the room, to check on the day’s NHL activities. Little did I know that somehow I put the transmitter in a “keyed” mode, with about 50w out on RTTY. I suspect I hit the F10 key (which starts transmission) When I sat the keyboard on my desk.

About 20-30 minutes later, I came back into the room and I smelled something hot. It was the 100w watt amplifier section of my K2. Maybe lucky for me today that I have that Amp in a separate enclosure from the K2, on top of my external antenna tuner. The heatsink was extremely hot, I could just quickly touch it without getting burned. The side panels of the Amp/Tuner were very warm. I powered-down the rig and grabbed a small electric fan. I spent about 10 minutes doing everything I could to remove heat from the enclosure.

I am still testing, but it appears that all is OK with the Amp/Tuner unit and the K2 itself has no idea….. I normally have a three-minute runaway transmitter timer attached to the power for the K2, because I use it for remote operation, where you are required to do so (although I know many people ignore this FCC requirement). On my newer rigs I always activate their built-in timeout timer, just in case. Of course the one time something like this would happen has to be when I am configuring the rig for Mobile operation and I have the timer disconnected.

I guess I dodged a bullet (am I still allowed to say that? Better check today’s Executive Orders). The only apparent damage done was the interference this may have caused. I can only apologize for that and hope it did not cause any problem for any stations. That said, the K2 seems to have made it through one nasty test. Glad I had the power down to 50 watts or this could have been a different story.

3 thoughts on “K2 Survives (apparently) the “Alpha Brick-on-the-Key” Test

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  1. Well, I have the same configuration with K2 as you, with KPA100 and KAT100 installed separately into an EC2 box. I haven’t actually done that kind of a “test”, but I’m running for instance Olivia with occasional very long transmissions up to 5 or 10 minutes. This causes the KPA100 heat sink to get VERY hot, but no damage to the PA. In the end of those long transmissions the KPA100 is still putting out the full 50W I use for digital modes. Of course, if you remember from the PA manual, the KPA100 does have overheating protection (the sensor is Q3), which reduces the power output by lowering the bias current if the output transistors (= heat sink) gets too hot (above +85 deg. C = about +180 deg. F). You would see “PA HOT” on the K2 display.
    Jukka – SV9RMU and OH2AXE

    1. Jukka,

      Thanks for the reminder about the overheating sensor. Should have expected that. Still, I was very concerned about the hot heatsink. It does seem to be a very robust design and mine has shown no issues since this accidental “test.” 73, Tom

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