[Elecraft] Filters

[Ed Gray W0SD]

We had good success this week end in the ARRL RTTY RU with the 500 hz 
roofing filter and a DSP setting of 300 hz most of the time.  At times 
we went to 250 hz. and used the 250 hz roofing filter when the going 
really got tough. We are talking about a serious effort to win # 1 which 
we have done in the past but most years we are second or third multi-op.

You really did not say if it is for RTTY general contacts, chasing DX or 
contesting? That is the key question!  If it is the first two then a 500 
hz roofing filter and and use the DSP to narrow down more when wanted 
would be all you need.  The 500 hz with DSP would be fine for CW as well.

If you want to contest on CW and RTTY then adding the 250 hz  roofing 
filter is worth having.  For CW if you want the ultimate then also 
adding the 200 khz roofing is great for contest CW and will work in a 
huge pileup on RTTY even though it rolls off the edges.  We did use it a 
fair amount this week end.  If you are not seriously into CW contesting 
but want to do some serious RTTY contesting the most you need it the 250 
hz roofing filter.

It is far two early to say but we did not seem to be able to see an 
advantage to the Dual PB but like I say we tried it some and could see 
no improvement and a couple of times we thought we seen it was worse so 
we quit using it.  Howeverthis was a quick gut feeling decision made in 
the midst of the competition so we may ultimately find it is OK.  Future 
firmware updates may make it more effective.

Using two K3's in some serious contest efforts this season starting with 
the IARU with a number of top 10 finishes according to unofficial 
results I have to back up what has been said on the users group many 
times and that is "IF" you are not in some very serious and I mean 
serious contest efforts with extreme crowding and big signals there is 
ABSOLUTELY no need to spend a lot of money on filters!!!  One for SSB, 
the one that comes with the radio is excellent and a 500 hz roofing 
filter for CW and RTTY is absolutely all you need and use the DSP! I can 
guarantee this to be true!  I am of course assuming you don't want to do 
FM and AM.

Ed W0SD