[Elecraft] P3 Panadapter with K2

[Geert Jan de Groot]

> Does anyone know if the P3 Panadapter will work with the K2 transceiver?

It does, with a number of caveats:
- The K2 does not have an IF Out port. On my K2, I never installed the 
no-antennatuner BNC connector; I modified the connector to use a small 
coax cable (AWAY from the high RF output of the antenna circuit to avoid 
leaks) and re-purposed the BNC for "IF Out". In hindsight, perhaps I 
should have used a SMA connector and some filler rings (for the same 
hole at the back of the K2)
- You need an IF buffer amplifier. Search for "Clifton Laboratories 
Z10000". The buffer amplifier comes in two versions, Z10000-K2 and 
Z10000-U. You want the K2 model, or get the universal model and add the 
4.915 Mhz filtering.
- The IF output is a tad low, you won't see "the bottom of the band" 
though I still found this useful
- The P3 cannot talk to the K2. Which means that there won't be 
frequencies on the P3 display, nor can you make the P3 "shift" as you 
can make the K3 do. The center will be the frequency you are receiving 
(which I consider most useful anyway), but that's what you get.
- The K2 has some BFO leakage back into the IF. For reception that does 
not matter; however for spectrum display you will find a spike in the 
center of the frequency you are receiving. There are some mods to make 
it "less" but not "gone". If you have a live band you probably won't 
notice; I was using the QO100 passband on which signals have a max 
strength of 24dB above noise and then the spike shows. I did not find it 
objectionable.

I do suggest you take some time to look up the original Clifton Z10000 
documentation; it is a piece of art on the same standard as the K2 
manual if not higher. I learned quite some things by just looking at the 
documentation. It is very unfortunate that Jack is no longer with us; 
however production of the amplifier has been taken over by DX 
engineering who sells pre-built boards which seem to be of similar 
standard as the ones Jack provided.

Is it useful? Definitely! Recommended? Yes. But you should know the 
limitations, which is why my posting is more verbose.

73,

Geert Jan PE1HZG