[Elecraft] K3 Mic Gain

[Gary]

I recently decided to test a very old low output/low impedance hand mic on
my K3 when I soon found some confusing information in the latest K3 manual.
My K3's firmware is current. I have two concerns: first, pg. 20 of the
owner's manual mentions additional mic gain can be enabled by tapping the 3
button in the MAIN:MIC SEL menu but when I tried the radio responded with
"N/A". I researched the firmware notes and found a change to this control
was made back in MCU 4.31 so that this gain 'boost' (to the front panel mic
only) can be enabled/disabled by pressing the 7 button, not the 3 button as
shown in the manual. Also the "boost" indicator has changed from ' to a
"high bar" symbol. I'm unclear on the "DSP mic boost (H or Hi)" reference in
the notes. I hope corrections to the K3 owner's manual pages 20 and 52 are
on Elecraft's to do list.

 

The second concern involves mic impedance. Except for a brief mention of
"Low-Z (~600 ohms)" on pg. 13 and "MIC MONO; hi- or low-Z" on pg 20 I
haven't found any mention of where Elecraft differentiates between high and
low mic impedance nor what may be too high or too low. Do any of you more
experienced K3 users and audio professionals know?

73,
Gary

N6LRV