[Elecraft] KX3 Feature Ask

[Edward R Cole]

Dave,

I bought my KX3 primarily for use as144-MHz mw IF.  I did some 
extensive freq measurements at 6m (before the 2m module was 
available).  I added an aftermarket heat sink and then ran the temp 
comp routine.  I simulated running JT65, which has continuous carrier 
for 50 seconds out of 2 minute sequences and found max drift was 
about 12-Hz.  That existed for the first two sequences and then drift 
dropped down to about 5-Hz (apparently residual heat held the offset 
for a longer time).

Since the 2m module utilizes a 55-MHz IF I would expect about the 
same performance.  Actually depends on power output and 2m max is 3w 
vs the 5w test I ran on 6m.  Seems 12-Hz variation on 10-GHz would 
not be troublesome if the mw LO was phase locked to a reference.  I 
have measured my 10-GHz LO to be about 17-Hz off frequency (no 
discernable drift) mainly due to frequency error in my OCXO on 10-MHz 
(which is multiplied to 10,224.000 MHz from 1,036 MHz).  I drive my 
DEMI 10G transverter at 1w on 144-MHz so drift would even be better.

So freq accuracy is < 17+12 Hz at 10,368 MHz.  Much better than the 
old Xosc system with the FT-817 which could be several KHz off freq.

I use an EIP538 mw freq counter which I check against a Rb source (5x E-11).

73, Ed - KL7UW

From: Dave AD6A <dave at ad6a.com>
To: Nr4c <nr4c at widomaker.com>
Cc: elecraft at mailman.qth.net
Subject: Re: [Elecraft] KX3 Feature Ask

A great little radio it is, agreed. I have two of them that I use as 
I.F. radios on my 10 & 24GHz portable microwave station setups. They 
are perfect for that function, using the 2m option as the I.F. 
especially when mated with a PX3. I drag my microwave gear all over 
the place, including mountain tops. I phase lock my microwave 
transverters to a GPS disciplined 10MHz OCXO and would simply like to 
be able to do the same with the I.F. radio so that I know exactly 
what frequency I'm on, especially when looking for exceedingly weak 
transmissions. I know for sure there are many of us microwavers that 
do the same thing.

FWIW I have a fully loaded K3s in my home station that's also locked 
to a GPS standard, as is all my RF test equipment.

Regards,
Dave AD6A


73, Ed - KL7UW
   http://www.kl7uw.com
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