[Elecraft] K3 transverter using 14 MHz I.F. - upper freq limit ?

[David Anderson]

Thanks Don,

On further internet searching I think I have answered my own question, but am happy to be corrected.

I suspect that the K3 Transverter ports reflect the same frequency limits as programmed into the radio as the main antenna port. The K3 is apparently software transmit ham band limited as far as I have read. It can be unlocked for "MARS" use, and that apparently gives general coverage transmit except around the IF and certain restrictions on power on the 27 MHz band.  

I don't have a K3 yet, I am thinking about one, but am also considering all other options. 

The KX3 with PX3 that I have performs exceptionally well on receive with my VHF transverter, but the transmit wideband noise at 50 kHz offset and beyond and some rather bad discrete spurious outputs are poor by comparison and I am not particularly happy running it into a Legal Limit amplifier if there are stations in close proximity (20km).  I realise that the KX3 is really designed as a QRP HF rig where such transmit noise and spurious outputs would be buried in the RF pollution on HF, but on VHF that isn't the case and greater care has to be taken.

So, armed with recently published figures comparing various transceivers I am looking at alternatives, the K3S is the best of the bunch, then the K3. I am excluding the top of the range Flex, as I prefer a real radio with knobs on. See RadCom Magazine March 2016 p22-27 High Performance VHF/UHF contest stations by Alwyn Seeds G8DOH. 

Of course finding a used K3 with the right options that I need (and they quickly add up) may be a problem. 

Prices in the UK from the dealer are £ for $, so buying direct from Elecraft in the USA is a still a better deal even with today's high shipping costs and 20% VAT.  At one time it was cheaper to take a transatlantic trip and bring a K3 back and still save money.

Slightly below the K3 but better than the KX3 in transmit purity at 50 kHz offset is the TS-590SG and it has an easy hardware mod for general coverage transmit coverage, so that is another option. However I do like Elecraft so provided it can do what I need that is what I would prefer.

I was surprised to find how out of calibration my transmit carrier null and opposite transmit sideband suppression was on my KX3 when I put it on an analyser. I was able to improve it by a great many dBs on all bands. I wonder as it was "built" by the UK dealer and I believe they align them.

73 from David GM4JJJ

> On 22 Feb 2016, at 22:36, Don Wilhelm <w3fpr at embarqmail.com> wrote:
> 
> David,
> 
> I don't know if the K3 transverter IF output is limited to the ham bands or not.  However, if it is, contact Elecraft report and they may be willing to send you a program to run which will open up the transmit limits.
> Be aware that the ham band bandpass filters may limit the power output as well as the receive passband.  You may want to install the KBPF3 if you do not already have one in your K3
> 
> 73,
> Don W3FPR
> 
>> On 2/22/2016 4:09 PM, David Anderson wrote:
>> I am thinking about a K3 for transverting to 144-146MHz using my existing transverter which has a 14-16MHz I.F.
>> 
>> It works well with the KX3,  does the K3 similarly allow transmit and receive on the transverter ports beyond the ham band frequency limits? I don't want to be limited to 144.350 MHz upper frequency.
>