sometimes it pays to read your own posts or errors. If your KPA100 has blue toroids at L15 and RFC1, then it is the new design (and is not the problem source). OTOH, if the toroids are at L15 and L16 and have red cores, the KPA100 should be updated with KPA100UPKIT.
73, Don W3FPR Jon, That sounds like a classic case of RF where it is not supposed to be - in other words, first check for RF feedback - lay out a 33 foot piece of wire connected only to the K2 at the near end, and insulated at the far end. If the effects decrease, then look to your antenna system for the cure to your 40 meter problems. OTOH, there was a problem with the KPA100 developing parasitic oscillations under certain conditions (like high SWR when using an auto-tuner like the KAT100), and that parasitic was most prevalent on 40 meters. That problem was addressed by the KPA100UPKIT and is included on newer KPA100s. If your KPA100 has blue toroids at L15 and L16, then adding the KPA100UPKIT would be a prudent step. If you have blue toroids at L16 and RFC1, then your KPA100 is up to date, and my suspicion about the RF Feedback situation is amplified. The fact that you can use the procedure for adjusting the output level on 20 meters says that the method is valid, but you have some sort of other situation present on 40. 73, Don W3FPR Jon Perelstein wrote: > Don, > > I'm having trouble with this approach on 40 meters. > > I set the power on the K2 to 30 watts and then adjusted > the TX volume on the SignaLink as high as I could without getting any ALC > reading. > > When I do that, I essentially have zero power output. There's no deflection > on the > K2's RF meter and someone who was monitoring my signal said that my signal > just dropped off the waterfall. I have a KAT100 and with these settings the > SWR light would not light, indicating that there isn't even enough power out > for the KAT100 to measure SWR). > > When I increased the SignaLink TX volume to get a 30 watt reading on the K2's > RF indicator, I was getting 2-4 bars of ALC. > > On my FT-897, the power display when I'm transmitting PSK is fairly steady. > On the K2 on 40 meters, it was bouncing all over the place, but that may be a > function of how the K2 measures RF power out?? > > I had no trouble using the suggested technique on 20 meters. > > Any ideas as to why I'm having problems on 40? > > Jon > KB1QBZ > > > > I had no problem using this approach on 20 meters, so I' > > --- On Wed, 4/28/10, Don Wilhelm <w3...@embarqmail.com> wrote: > I would recommend setting the power to 30 watts. Then hold DISPLAY to change > the metering to ALC - adjust the audio up just to the point where there is no > ALC indication (adjust until you see ALC bars and then back off until there > are none). That should give you a cleaner signal and better control of the > output level. Since the gain of the K2 transmit chain varies from band to > band, you may have to check the audio drive level again when changing to a > different band. For further explanation, read on. > ______________________________________________________________ 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
