If these reports are correct, then additional I.F. gain isn't the answer. If weak signals aren't being heard, it's because the signal/noise (S/N) ratio isn't as good on 10 as it is with the comparison rig.
If so, something's wrong with the K3 in question. It's simple to check a K3 for adequate S/N. If the background noise increases appreciably (3 dB or so) when the antenna is connected, using the same bandwidth, the K3 has all the S/N it can use. The rise in noise clearly indicates that the ability to hear weak signals is entirely limited by the band noise. If not, turn the K3 preamp on. The preamp is a low-noise amplifier that improves the S/N. As mentioned often before, it is a bad idea to use the preamp on bands where the above test shows it is not needed because it amplifies *all* signals coming into the K3. That means the K3's dynamic range (ability to handle big signals without creating artifacts) is reduced when the preamp is used. That reduction in dynamic range is often never noticed, but if a really strong signal is present on the band it might produce undesirable "trash" on the frequency of the desired signal. Because the band noise on 10 meters and frequencies down to 20 meters is so low, the preamp is typically used with any antenna on those bands unless the local noise level is unusually high. Also, the preamp might be used on the lower frequency bands when a very low-gain antenna, such as a mobile whip, is used in a r.f. quiet location. Ron AC7AC -----Original Message----- This seems to come up every year after the ARRL 10M contest. Perhaps an extra 10dB of i.f. gain on 10M could be programmed into dsp firmware. 73, Barry N1EU Jorge Diez - CX6VM wrote: > > We heard two or three very weak signals from PY in the TS850 that were not > heard in the K3.. > ______________________________________________________________ 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
