Hi Dave, If the K3 is running Beta MCU 5.26 then there is a new configuration setting which applies when the KXV3B is installed. Here is the explanation from the 5.26 notes.
* PREAMP 2 and CONFIG:PREAMP2 MENU ENTRY (KXV3B): This menu entry is only applicable if a KXV3B module is installed (supplied with the K3S). It also only applies if the current band is 12, 10, or 6 meters. If PREAMP2 is set to ON, then the PRE switch rotates through settings of OFF, PRE 1, and PRE 2 on the applicable band. PRE 2 turns on the low-noise preamp on the KXV3B module (+20 dB, with a typical NF of -144 dBm on 12/10/6 meters). When PRE 2 is selected, the PRE icon will flash slowly. Note: Do not use an external preamplifier (such as an Elecraft PR6 or PR6-10) when using the built-in low-noise preamp (PRE 2). This would result in excessive gain. Here are two posts made by Wayne: On 5/21/2015 7:42 AM, Wayne Burdick wrote: >>>> The addition of the low-noise amplifier for 12-6 meters is the only >> change. >>>> The module is compatible with either the K3 or K3S. The manual will >>>> be posted when it's complete. >>>> >>>> 73, >>>> Wayne >>>> N6KR On 5/22/2015 5:07 PM, Wayne Burdick wrote: > On May 22, 2015, at 12:41 PM, "N2TK, Tony" <tony....@verizon.net> wrote: > > Preamp 2, on the KXV3B, is in addition to the normal preamp (preamp 1). But firmware will only let you turn on one or the other -- not both. When preamp 2 is ON, it totally dominates the noise figure equation, so there's no value in also turning on preamp 1. Preamp 2 has a gain of 20 dB, while preamp 1 has a gain of 10 dB. > > To turn preamp 2 ON, you first have to enable it on one or more of the applicable bands using the CONFIG:PREAMP2 menu entry. You can enable it on 12, 10, and 6 meters. > > Once preamp 2 is enabled, tapping PRE cycles through OFF/PRE1/PRE2 on the applicable band. Other bands will only show OFF/PRE1. > > When PRE2 is selected, the PRE icon flashes slowly as a reminder. > > 73, > Wayne > N6KR 73, Mike K2MK -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-KXV3B-in-an-Older-K3-tp7603673p7603674.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com