Hello, I recently had the following issue and was wondering if a firmware feature could be added to make it impossible to do what I did:
I put up a nonresonant dipole and connected it to the K3. I wanted to test the antenna on 40m so I tuned up with the built-in antenna tuner which obtained a 1:1 (or very close) match. I wanted to verify that the balun I made was not prone to heating up, so I figured I'd put the K3 in tune mode for a a minute or so. About 15 seconds into this, smoke started coming from the K3. Turns out there was too much reflected power and it heated up the filter (blue toroid + capacitors) on the KAT3 which is designed to prevent energy from the IF from being part of the transmitted signal. 40M was apparently close enough to cause this to heat up. I'm wondering if it would be possible to have the firmware prevent excessive reflected power situations (by limiting forward power if the pre-KAT3 SWR is too high) on 40m or any other bands close enough to the IF frequency to cause the filter to heat up (not sure if this is also a risk on 30m). The support I received from Elecraft on this issue was superb. I just figured that I'd put it in as a firmware request b/c I think K3 users may not realize that connecting a nonresonant antenna can be dangerous to the K3 on 40m, and it would seem that the same approach of reducing forward power used to protect the finals could also be used to protect the filter. 73, Matt NQ6N ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
