[Elecraft] K3s and DEMI transverter

[Ed Cole]

Previous to 2010, I was using a FT-847 for 50,144,432 MHz and a DEMI on 
1296 with 144 IF.

That was the year I bought my K3-10* (since updated with new synth).  I 
bought DEMI 144-28, 222-28, 432-28* and 1296-28 transverters as better 
design filtered LO better making 28-MHz a good choice for use with my 
K3.  Note: * indicates use of PLL locked to 10-MHz reference resulting 
in less than 2-Hz max drift on 28-MHz.  Choice of LO frequency is 
determined by ability to reject LO feed thru (primarily). Picking a too 
low IF can lead to troubles.

I also have DEMI 3400-145* and 10,368-144* transverters.  Use of 144 or 
432 as IF at 1296 and above is common.  They use the N5AC A32 PLL to 
lock LO.  The A32 is now NLA so look at DEMI digiLO as replacement.  
Currently using an OCXO as 10-MHz ref but will switch to GPSDO this summer.

Eventually Elecraft will offer 144 and 432 transverter modules for the 
K4.  Will be curious what IF is chosen.

73, Ed - KL7UW


On 2 Jun 2021, at 15:46, Mooneer Salem<mooneer at gmail.com>  wrote:

Personally, I like choices, so I've considered getting a 10MHz IF if I ever
got deep into transverters.

I would be concerned that the 10MHz station reference would appear as an in band signal.

The other IF commonly used is 14MHz (by Kuhne for example), but we use 28MHz on all our VHF and up contest transverters. If you want to see how we do with this arrangement  look up G5LK/P and G3M in the UK listing for the major portable contests.

Stewart/G3YSX