[Elecraft] K3EXREF Query

[Edward R Cole]

David,

10w is 7.3 kwH/month.  I would doubt that is a large expense, even in 
GB.  Locally, its about 8 cents/kwH but in the bush it might be as 
high as a couple dollars since diesel fuel for the generators costs 
are huge (local diesel is $4.10).  I know it would require conversion 
to liters and all that to come up with equivalent costs, but most 
households run hundreds of kwh/mo.  Leave your TV plugged in but 
turned off and it still consumes about 50w.  I have plug strip to 
remove ac from all my home TV systems when not in use.  I leave power 
to the satellite receiver as it keeps the LNB powered and stable 
(Otherwise it takes 5-10 minutes to acquire signal and download data 
at startup).

Simple solution is to leave the reference oscillator running 
continually.  The K3 TCXO-3 will still drift on power up but this is 
compensated by EXREF every 4-seconds so frequency stability is held 
to better than 0.1 ppm.  I measured +/- 2 Hz at 28-MHz on my K3.  But 
if you watch the REF*CAL frequency you will note it incrementing from 
49.380.000 to something like 49.380.080 in several minutes and then 
settle down near that value (indicating start-up drift has stopped).

By not running your reference full time you will have to wait 15 to 
30 minutes for it to fully warm up.  I also have a rubidium but run 
it only for precise frequency calibration of the OCXO couple times 
per year.  My mw counter internal TCXO is always in agreement with 
the Rb so I do not bother for routine frequency checks.  The rb is 
only +/- 5 E-11 so not as good as GPS but good enough for my use.

73, Ed - KL7UW
-------------
From: David G4DMP <david at g4dmp.fsnet.co.uk>
To: Mike Harris <mike.harris at horizon.co.fk>
Cc: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3EXREF Query
Message-ID: <ulj9AOEp0TPUFwk3 at g4dmp.fsnet.co.uk>
Content-Type: text/plain;charset=us-ascii

About 10W for the MV89A double oven CXO, when run from a linear 12V
power supply. NOT trivial at today's prices for electricity in Great
Britain.

73 de David G4DMP



73, Ed - KL7UW
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