[Elecraft] K3EXREF - What am I doing wrong

[Edward R Cole]

Wow! Great tip -- totally forgot the "tap" "2" step.

My EXREF had quit some time ago and checking 10-MHz sources all 
tested good so I figured my "beta test" unit had given it up.  Too 
busy to investigate further.

It stopped after I had a firmware glitch so now guessing that shut 
off the EXREF.

So I did the tap-2 and REF CAL showed no asterisk - uh oh.  I changed 
10-MHz source (I have a 4-way distribution amp) and still 
nothing.  So "utilizing my trouble shooting skills" I decided to 
check the coax and found the sma connector not fully tightened at the 
K3.  About 1/2 turn is all it took and REF * CAL with asterisk 
blinking and the 49.380.000 oscillator is shifting upward again 
compensating TCXO drift (mine tops out at about 49.380.072).

Its my belief the upward drift is from initial radio warm-up and once 
it reaches operating temp** is reached its fairly stable varying only 
a few Hz.  My Beta Tests indicate my EXREF holds my K3/10 within 2-Hz 
at 28-MHz (which is my IF for transverter operation). I have a mw 
frequency counter (with internal TCXO) for checking and also a 
Rubidium oscillator which I use as my Frequency standard.  Counter 
TCXO is never off 1-Hz from the Rb source.  The OCXO requires 
adjustment about 2 times per year for long-term drift.  **NOTE: I 
have a K3/10 so the 10w amp doesn't produce a lot of heat.  When I 
operate in transverter mode the K3 operates at 1mw with no extra heat 
in Tx.  If you have a K3/100 that could be different when on HF/6m.

I did find one of my four port distribution amp has no output (BNC 
appears loose so probably has broke off the wire inside).  I have a 
432 and 1296 transverter that both use a synth-PLL LO locked to 
10-MHz.  My source is a $45 e-bay Russian surplus OCXO.

My Point: Beware that sma must be properly tight to have good contact.

73, Ed - KL7UW
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