[Elecraft] XVTR IF BAND CAN NOW BE 10 OR 18 MHZ

[Edward R Cole]

Just to expand a big on what Wayne states:

Operation on the upcoming (but not yet established by the FCC) new 
600 meter ham band on 472-479 KHz, K3 use is enhanced by this upgrade 
in the firmware.  It allows operating the K3 on 10.472-10.479 MHz as 
the IF input to a transverter which can use a super-stable OCXO or 
GPS disciplined oscillator as the 10 MHz LO.  Since there will only 
be 7-Hz spectrum in the whole ham band only narrow band modes will be 
allowed.  Stations will need to hold +/- 1-Hz in frequency stability 
and accuracy to avoid interfering with each other.

I use a surplus OCXO (Oven Controlled Xtal Oscillator) that I bought 
on e-bay for $45.  This holds my K3 to 0.01ppm by use of the EXREF 
and TCXO-3 options.  On 10-MHz band this results in under 1-Hz 
drift.  Using a transverter that has drift considerably below 1-Hz 
permits me to use my K3/10 (w/ KVX3) on this new band.

I am in early design process to make such a transverter with 25w 
output and utilizing a 10-MHz OCXO for LO.  At this time I'm 
considering offering it as a kit.  Only 1mw RF level is needed by the 
transverter for IF drive.  I expect this is six months off in 
realizing.  It would also be nice if the KX3 was able to work at 
10.472-10.500 MHz.

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

From: Wayne Burdick <n6kr at elecraft.com>
To: todd ruby <todd at ruby-wine.com>
Cc: Elecraft Reflector Reflector <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] XVTR IF BAND CAN NOW BE 10 OR 18 MHZ
Message-ID: <1203FC98-0458-4647-8F79-89264F676F93 at elecraft.com>
Content-Type: text/plain; charset=us-ascii

There's no particular benefit to an 18-MHz I.F. But 10 MHz can be 
useful for VLF/LF transverters (e.g., 500 kHz) because very 
high-stability 10-MHz oscillators (OCO's, or oven-controlled 
oscillators, etc.) are available at low cost for use as the mixer 
injection oscillator. This combined with the K3's excellent stability 
can allow the use of extremely narrowband modes that require very low drift.

73,
Wayne
N6KR


73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
Dubus Mag business:
     dubususa at gmail.com