Bill I run a similar setup portable and have played around with various ways to link the radio and amp. I also run an FTDX5000 as my main base station with the Expert
Firstly make sure that you have ALC turned off on the K3 otherwise the amp will attempt to set the drive to achieve one of the three set output levels. Secondly I would not worry too much about what the amp says it's input level is. I never get correlating results between the amp and my new LP700 (very nice bit of kit) on either the input or output. Give that a try and also try varying the drive from the K3. If the output stays the same thats going to mean the ALC is controlling the drive Trevor MØTDZ Message: 24 Date: Sun, 10 Sep 2017 14:10:02 -0700 From: Bill Frantz <fra...@pwpconsult.com> To: elecraft@mailman.qth.net Subject: [Elecraft] K3 and Expert 1.3K-FA amplifier power Message-ID: <r470Ps-10126i-54EA0FED42B04930A468A52546569AF8@Williams-MacBook-Pro.local> Content-Type: text/plain; charset=UTF-8; format=flowed I have just set up an Expert 1.3K-FA amplifier with my K3 (with most of the upgrades to become a K3S). My question is, when I drive it with 10W set on the K3 output power, it shows a drive level of about 30W and and output level of 950W. What is going on? Details: The two boxes are connected with about 6' of RG-58 for the RF and a custom cable made by KC5PCB, Dan Tassell for the rest of the signals. The output is into a dummy load, although very similar measurements occur with my trapped vertical antenna. Tests were in the CW portion of the 20M band. The Amp is powered from a dedicated 120V circuit which shows a 7 volt drop at 12.7A during CW key down transmission. (Voltage is measured by a Fluke 87 DVM and current by a Kill-A-Watt PA4400.) An external YS-60 power meter shows 800W, which seems reasonable agreement given the accuracy of RF power measurements. Why does the K3 show 10W and the amp show 30W? Is there something screwy here, or is it normal? 73 Bill AE6JV 2EØLDZ Trevor Clapp M. 07900 49 77 11 ______________________________________________________________ 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
