[Elecraft] K2 & transverter question

[Mike-WE0H]

Hi Don,

I can drop the level down and divide as you said. That would be easy 
enough. I wonder if the software of the K2 could be changed to allow any 
HF band to be used as an IF with that K60XV board? Who would I speak 
with about changing the software?

Otherwise I'll continue to look for a oven oscillator at those 4 
baseband freq's. If I can't find one then I will have to use your method 
to generate some harmonics and pick the 7.0mc signal and buffer/filter 
it for the mixer. One way or the other it'll get done...hi hi...

Thanks,
Mike



Don Wilhelm wrote:
> Mike,
>
> It is a matter of firmware, not hardware limitations.
> I would guess that when the K60XV was released, no one thought it 
> would ever be used for down-converting, so only the normal VHF IF 
> frequencies were made available.
>
> Since your current oscillator is super-stable, have you considered 
> using it as a standard.  Use a digital counter to divide by 3 - that 
> will produce a square wave which is rich in odd order harmonics - a 
> tuned circuit could then pick off the 7th harmonic of the 1 kHz 
> frequency.  I don't know if it would work easily for you, but I think 
> it would be viable enough to experiment with.
>
> 73,
> Don W3FPR
>
> Mike-WE0H wrote:
>> Hi Don,
>>
>> Wow that does present an issue now. I will see if I can find a 
>> suitable reference oscillator at one of those 4 freq's. Seems kind of 
>> odd IF freq's not having one at 10.0mc. Does anyone has a suggestion 
>> on what oscillator I could brew up that would stay on freq within 1 
>> cycle for over 24 hours after warm up? That is the reason why I now 
>> run a oven oscillator because it never changes freq month after month 
>> and has zero drift. I run digital modes down there that won't 
>> tolerate even a 1 cycle drift. My oscillator's are a commercial 
>> assembly from old analog cell sites. Got a deal on them years ago and 
>> built my LF & MF station around them.
>>
>> Thanks much,
>> Mike
>> WE0H
>>
>>
>>
>> Don  wrote:
>>  
>>> Mike,
>>>
>>> The K60XV will not provide any advantage for you with that IF 
>>> frequency band.  The available IF frequencies for the K2 transverter 
>>> bands are limited to 7 MHz, 14 MHz, 21 MHz and 28 MHz.  These are 
>>> 'bottom of the band' frequencies and tuning will be upward from there.
>>>
>>> You can use the normal K2 BNC output (SO-239 if you have the KPA100 
>>> installed) and translate the actual transverter input frequency in 
>>> your head.  You may be doing that already with your Kenwood.
>>> If you really need to use the K60XV output, you will need to modify 
>>> your transverter to use one of the available IF frequencies.
>>>
>>> You will also not be able to have the K2 directly readout the 
>>> frequency in that input band, but if you do change your transverter 
>>> to use the K60XV, you might want to 'fool' the K2 by entering 50 MHz 
>>> as the RF band and ignore the first digit on the display to obtain 
>>> the proper frequency.
>>>
>>> In other words, you could use the K60XV if you changed the 
>>> transverter oscillator to 7 MHz instead of your current 3 MHz and 
>>> reworked the IF bandpass for 7000 to 7510 kHz, the K2 would tune 
>>> from 7000 kHz to 7510 kHz to cover the input frequencies from DC to 
>>> 510 kHz.  If you selected 50 MHz as the RF band, you would see 
>>> 50000.00 to 50550.00 on the K2 display.
>>>
>>> 73,
>>> Don W3FPR
>>>     
>>
>>  
>>> Mike-WE0H wrote:
>>>    
>>>> Building my K2 next week. I run 600 meters and use a homebrew 
>>>> transverter right now with my Kenwood HF rig. Going to build a new 
>>>> transverter for my K2 when it is finished. I ordered the 
>>>> transverter option. I need the K2 to function from 3.135mc to 
>>>> 3.510mc as I use a 3.0mc oven oscillator as my reference mixed with 
>>>> the HF radio's signal to get me on 2200, 1750 & 600 meters. I am 
>>>> licensed as a Part 5 station on those 3 bands. Will the K2 operate 
>>>> in that band at & below 80 meters? I only need the transverter 
>>>> ports to function, not the HF power amp.
>>>>
>>>> Many thanks,
>>>> Mike
>>>> WE0H
>>>>  
>>>>       
>>
>