[Elecraft] APF in 4.16/2.63 works well!

[Joe Subich, W4TV]

I agree with Bill.  I've had a chance to preview the APF function and
it seems to operate very well although I haven't seen a any really
weak stations like 5R8RJ on 160.

APF as implemented by Lyle may become an alternative to a very narrow
(e.g. 250 or 200 Hz) CW filter for casual operators as it provides a
"spotlight" selectivity but does not provide the same level of IF
protection as the tighter first IF filter.

The one reservation I have is the potential need to use the menu
system to select between the original Dual PB filter and APF.  I
would much prefer to see a two level "hold" - normal (500 ms) hold
for Dual PB and long (1 sec) hold for APF like Link and Diversity
with the KRX3 - for selecting Dual PB or APF.

There are a few other control items and questions about use with the
programmer's interface to be resolved but it looks like the capability
is well on its way to a wider public beta.

73,

    ... Joe, W4TV


On 10/29/2010 7:02 AM, Bill W4ZV wrote:
>
> Wayne released APF to Field Test last night and also said it was OK to post
> comments.  It seems to work very well and I expect it will be released
> publicly soon.
>
> APF (as implemented in the FT-1000) has always been a weak signal receiving
> tool.  It's not for adjusting PITCH or some of the other ideas discussed.
> Last night I happened to be listening on 160m around 02z just after I got it
> installed.  5R8RJ usually comes on 1826.44 a little before his sunrise.
> Conditions were very poor but he was spotted by a UA4 around 0210z.   I
> could hear nothing of him on his normal frequency.  CW Skimmer's waterfall
> was also showing absolutely no signal there...not even a faint trace.  I
> then actuated APF and could then copy him about Q3 in the noise.
>
> This is exactly what APF is designed for...pulling extremely weak signals
> out of noise...and it does it very well.  The user interface is also very
> simple.  Although it may change slightly before public release, you hold
> DUAL PB (as though you were going into the previous CW focus mode) and then
> adjust SHIFT in 10 Hz steps to peak the signal (independent of your PITCH
> setting).  It works well in diversity also.
>
> Nice job guys...all the previous FT-1000 owners will rejoice!
>
> 73,  Bill  W4ZV