[Elecraft] Anew k3 owner de ai5os.

[W3FPR]

Justin,

A few more comments on the K3 xtal filters, it is important to remember 
that these are "roofing filters" - while the DSP filters are effective 
at narrowing the bandpass to whatever you want, a wide filter will not 
protect the DSP front end and the AGC from strong signals outside the 
DSP bandwidth that you are dialed into.  That can cause AGC 'pumping' 
and DSP overload from signals that you cannot hear (because they are 
outside the DSP bandpass). If you have a very quiet location, far away 
from other strong local signals, the DSP filtering alone may be OK for 
you.  But if you have ham neighbors who run high power, you may want to 
invest in the more narrow filters.  Otherwise, the DSP filters 
controlled by the Width knob will give you the ultimate and final 
bandwidth that you are listening to.
Signals outside your listening bandwidth that are S9+30 dB will give you 
trouble, lesser signals not so much.

This was discussed in detail many years ago after the K3 was 
introduced.  You may want to comb the K3 archives to learn more about 
the roofing filters and what they accomplish.

73,
Don W3FPR

On 5/3/2024 6:25 PM, Justin Mann via Elecraft wrote:
> FOlks,
> I’ve just purchased a new-to-me K3, serial number 7766.  The rig seems to be grate, works well, but I’m new at Elecraft, and the way somethings are done.  I notice that the rig has the original 2.8K filter installed, so I’m thinking that I should add a few more filter to optimize performance with some different modes.  Were I to add a 250 HZ CW filter would that also work at 500 HZ?  Also, is there any advantage to upgrading the original synthesizer to the KSYN3a?  I hear that does make the rig a bit quieter.. Would I notice that during normal use?  I’d also like to add some kind of a transverter so that the rig could extend it’s capabilities out to 144 MHZ, is that possible, are there any of those units available on the used market?
> Thanks,
> Justin-ai5os
>