If Howard is correct on the output level, it's a little low for the K3EXREF's input. From the manual:
Connect the external 10 MHz signal source to the K3 rear panel REF. connector. The 10 MHz source should have a signal level between +4 dBm and +16 dBm, nominal. For square wave sources, 2VDC to 3.3VDC peak is optimum. If the source is a 5V logic level, use a 50-ohm resistor in series with the input. Caution: To avoid damage to the K3EXREF, do not exceed these levels. Many K3EXREF users have Trimble Thunderbolt units. These work quite well and have an output level of about 12.5 dBm, sine wave. Thunderbolt units can be acquired surplus for $40 - $100 and are readily available on eBay, etc. I'd recommend you buy one of the later models, because these have an integrated 12V-input power supply. 73, matt W6NIA On Wed, 8 Jan 2014 10:00:46 -0600, you wrote: >This is an inquiry I sent to Elecraft, along with their response: > >Ive been considering adding the K3XREF to my K3. Can you tell me if the >device listed in this link is a suitable 10MHz source? (Re: Navsync CW12-TIM >GPS Timing Module. Price and technical details at the link:) > >http://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=41718 > >Thanks, > >Jon / KF5TFJ >===== >Jon, > >We have not tested that unit with the K3XREF. >Looking at the specs, it's uses a square wave (most use a sign) and the >output is a little higher output then 0dBM which most units use. >I would recommended asking on our Elecraft reflector if anyone has used and >tested it with the K3. > >Regards >Howard K6IA >===== >So, has anyone used the CW12-TIM with K3EXREF? >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:Elecraft@mailman.qth.net > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
