|Minimal stress on the headphone jack|
|By all means avoid this situation!|
- Failing headphone jack: One of the most frequent complaints is the need to replace the headphone jack. Mine has lasted for ten years by being careful not to put undue stress on it. The best thing to do is to use an angled plug for the headphone (left-hand image). Many headphones have that and it is a good way to minimize the mechanical stress. The worst one can do is surely to put a long mini-jack to jack adapter plug directly into the headphone jack (right-hand image).
- Transmission immediately after a band change. The K2 transmitter's automatic level control (ALC) needs some time to settle after a band change. In a CW contest, this is easy to forget, but the effect is that the first part of your call sign may be chopped off, e.g. my LA3... becomes DA3... or SA3... One should find an empty frequency and transmit for half a second or so first, in order for the transmit level to come up to the desired level.
- Sidetone frequency: Don't be tempted to adjust the sidetone frequency if you want it higher or lower in pitch (Menu, sidetone P menu). Many radios allow this and the K2's menu gives the impression that it is straightforward to do so. The flip side of the coin is that all the filter settings (XFIL) and the audio filter (KAF2) also need to be readjusted, otherwise the filters will not match the new sidetone.
- Missing sidetone: A recurring question on the Elecraft mailing list is the sudden lack of sidetone, caused by a nonintended change of the menu entry where the sidetone source can be switched. See details in the response from Don Wilhelm, W3FPR.
- Serial interface cable: Don't connect the RS232 connector via a standard serial cable to a device with a serial port. It is likely that you will damage the K2's power sensing system, sometimes also the 100 W PA and the SSB adaptor, see memo from Gary Surrency (AB7MY) & Tom Hammond (NØSS). The best way is to modify the connector as per the illustrated instructions from Willie Hew, KH6NO/W7.
- Noise blanker test: If you find that the noise blanker seems not to work, then don't write it off until this simple test has been performed where a screwdriver is used to touch the case of Q21.