K3 Hi Cut & Low Cut granularity bug? Lately I've been running a number of digital modes (JT65A, PSK31 & RTTY) on the HF bands. The K3's APF and dual PB filters really help to copy weak RTTY signals, especially when there is QRM. When using the JT65A mode, signals even weaker than -20 dB can be copied. These very weak signals are often effected by much stronger signals within the receiver's pass band. Often, these very strong signals will act on the K3's AGC and push the weaker signals farther into the noise, making them uncopyable.
I have found that adjusting the K3's 'Hi' and 'Lo' cut filters to be the quickest and easiest way to reduce the QRM from adjacent loud signals. At times an offending strong station is very close to the weak signal's frequency. The 'Hi-Cut' and 'Lo-Cut' filters must be adjusted so they attenuate the nearby loud interfering signal but not the weak signal you are attempting to copy. Unfortunately, these controls can only be adjusted in 100 Hz increments. Although the SHIFT can be set up for 10Hz or 50 Hz increments, at present the granularity of the K3's WIDTH, HI CUT, and LOW CUT controls can only be set to 100 Hz in the CW & Digital modes. Also, when the SHIFT granularity (CONFIG:PB CTL) is changed from 50Hz to 10Hz, the Hi Cut and Low Cut controls do not work at all! Is this a BUG or a FEATURE? I'm presently using K3 firmware update MCU 4.36 . It would be very helpful if the 'Hi-Cut' and 'Lo-Cut' filtering could be adjusted in smaller increments than the present 100Hz. Being able to fine tune the Hi and Low cut filters would really help to quickly and easily reduce QRM that might develop either above or below the digital signal being copied. I hope that this request can be implemented in a future revision of K3 software. 73, Rich - K1HTV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
