I built K2 s/n 06424 some time ago, then added KSB2 and finally converted it to 100W a few years ago. Usually used it for CW only, but recently moved it to main operating position and started using it on 40M LSB mornings. To my chagrin, received comment few days ago that I was off frequency, and this morning confirmed with another op that I was 50 Hz low. The problem cleared after about 10 minutes.
He mentioned that his K2/100 behaved the same way when first turned on and that this was known and "normal" behavior. Is this true? Thanks and 73, Curt KB5JO ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Curt,
A lot of information can be gleaned from reading the K2 specifications which say the VFO stability is less than 100 Hz drift typical from a cold start at 25 degC. That means yours is well within specification. That also means you should let it warm up for 15 minutes or so from a cold start. There is a means of adjusting the thermal compensation of the K2, but it takes a bit of experimentation, patience, and measurement. It involves changing the 1/4 watt resistor value on the Thermistor board. Download the PLL Upgrade instructions and look at page 4 of those instructions. Your K2 already has the PLL upgrade installed (I can tell from the serial number), but the upgrade instructions is the only place where the additional compensation adjustment is documented. Note that the first step of the instruction is to allow the K2 to warm up for 30 minutes. If your K2 does not drift excessively after a warmup period, you will not be able to improve it after the extended stability procedure. 73, Don W3FPR On 9/11/2017 9:13 AM, Curt wrote: > I built K2 s/n 06424 some time ago, then added KSB2 and finally converted it to 100W a few years ago. Usually used it for CW only, but recently moved it to main operating position and started using it on 40M LSB mornings. To my chagrin, received comment few days ago that I was off frequency, and this morning confirmed with another op that I was 50 Hz low. The problem cleared after about 10 minutes. > > He mentioned that his K2/100 behaved the same way when first turned on and that this was known and "normal" behavior. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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