Roofing filter question

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03-21-2013, 05:55 PM
KB3LAZ

Roofing filter question

Just weighing my options here. Lets talk about SSB atm. If I have a 2.8 filter and a 1.8 filter, is there really a need for a 2.1 filter? 2.8 (normally what I run for ssb ragchew, well 2.7-3 depending on the rigs I have owned) will work just fine for SSB ragchew. I would venture to say that 2.1 and 1.8 are more often than not both used for DX and or contesting in a crowded band.

The difference in bandwidth does not seem all that large. I guess what I am wondering is, is there a significant difference between the two and what is the advantage to having one over the other, if any?

That being said, most rigs that I have owned have only ever had 1 filter for SSB. Be it 2.4, 2.5, 2.7, or 3.

Why do I ask? Well, for quite some time now I have been working out how I want to order my K3 when I get back state side.

I have decided that the filter lineup will be
6 (still on the fence about this as I dont intend to use the rig for AM but I do a bit of ESSB here and there)
2.8 swap
2.1 and or 1.8 but am unsure
250hz

Now that we are at it, I will mention other things that I am for, against, or on the fence about. Suggestions one way or the other are welcome.

For
P3
KAT3 (ATU)
KT3XCO3-1 (TCXO)
KXV3A (RX AT, IF out, XVERT)

Against
13k fliter
2m Module
KDVR3

On the fence
P3SVGA (Video Adapter)
KRX3 (SUB RX)
KBPF3 (Gen Cov)

Okay, so the filter question would be great to have answered. Suggestions otherwise are just gravy. Now, I know that the Sub RX does have its advantages but I am just not sure that I will use it enough to justify the extra cost of both it and the filters to compliment it. I have had very few radios in the past with a Sub RX and those that did have, I never used the option. Many say its better to be safe than sorry, idk.

Again, opinions welcome.

(PS: SSB/CW use only. I will not use AM nor digi modes. Mostly Ragchew with occasional DX and contesting.)

Thank you for your time and suggestions.

Sorry, cant change the title to say K3 questions...Initially the post was only about the roofing filter, lol.
03-21-2013, 06:05 PM
NQ6U

One of the nice things about about the K3 is you can add stuff at any time. Install the items you're sure about now, add the others later.
03-21-2013, 06:12 PM
KB3LAZ

Quote:

Originally Posted by KJ6BSO

One of the nice things about about the K3 is you can add stuff at any time. Install the items you're sure about now, add the others later.

I know, which is one of the main reasons I have put so much thought into the radio. That as well as the continuous updates. That aside, there are just some things that I have zero experience with and would like suggestions. :) Example: Contesting and what filters are more useful than others. I hear people talk about using a 1.8 or 2.1 filter but I have no clue if there is really a need for both as you can use the DSP to manipulate your BW.
03-21-2013, 06:22 PM
NQ6U

Just in case you haven't already noticed this:

http://www.elecraft.com/K3/Roofing_Filters.htm

Nice little discussion about filter choices.
03-21-2013, 06:26 PM
KB3LAZ

Quote:

Originally Posted by KJ6BSO

Just in case you haven't already noticed this:

http://www.elecraft.com/K3/Roofing_Filters.htm

Nice little discussion about filter choices.

Yes, I have read it, thank you. In fact Im not sure there is much on the net that I havent read concerning the radio and its accessories. But for some questions I have not been able to find specific answers. Or at least not in noob speak. :)
03-21-2013, 06:43 PM
NQ6U

After reading that document, I think I'd go for the 2.8 kHz eight-pole and the 400 Hz eight-pole filter for CW work. The 200 is probably too tight unless you're seriously into heavy-duty CW contesting.
03-21-2013, 08:37 PM
KJ3N

Get the 1.8khz for SSB contesting. Between that and the stock 2.7khz, you're covered for SSB.

You don't want my opinion on ESSB.

You can get the 250hz for CW, but if you ever do any RTTY (which I do occasionally), I think a better compromise would be the 400hz filter. JMO

I would rethink your decision on the DVR. For SSB contesting, you're going to need it.

A second RX comes in handy for DX chasing, but I would wait until you've had some time in the chair with the radio first. I waited about a year before I bought the 2nd RX.

YMMV
03-22-2013, 06:47 AM
KB3LAZ

Quote:

Originally Posted by KJ3N

Get the 1.8khz for SSB contesting. Between that and the stock 2.7khz, you're covered for SSB.

You don't want my opinion on ESSB.

You can get the 250hz for CW, but if you ever do any RTTY (which I do occasionally), I think a better compromise would be the 400hz filter. JMO

I would rethink your decision on the DVR. For SSB contesting, you're going to need it.

A second RX comes in handy for DX chasing, but I would wait until you've had some time in the chair with the radio first. I waited about a year before I bought the 2nd RX.

YMMV

Thank you, Jim. I hadnt thought about that use for the DVR. Im not a digital fan but I guess the 400hz filter woudnt hurt to be safe either.

As for the second RX, its something I have to think long and hard about. I know it has so many uses, even those I had never thought about until researching the radio. I know I dont praticularly need it for an RX antenna, however, I have been looking into diversity reception. This seems to be something that I can find only very basic info on. From what I have seen its using two antennas one wave length apart allowing you for a wider coverage area for reception and longer periods without signal fade. Again, from what I understand, you use one antenna for a dedicated RX on the sub RX and one for bother RX and TX on the main. This also makes me wonder if it is possible to use both the First and Second RX for RX antennas and the first Main for a separate TX antenna. I dont see why this would be an issue as it would be a similar concept to using an RX antenna on a single RX rig. Example: Two loops for RX and an inverted V for transmit. Or what have you.

Eh...just my ramblings.
03-30-2013, 08:29 AM
N8YX

I have the following rig/filter SSB/CW combinations in use here:

IC-751A - 2.4KHz/2.1KHz/500Hz/250Hz
R-71A - 2.4KHz/2.1KHz/500Hz, 2.4KHz/1.9KHz/250Hz (latter RX is for 160-40M work)
Omni V/VI/Paragon II - 2.4KHz/1.8KHz/500Hz/250Hz
TR7/R7 - 2.3KHz/1.8KHz/500Hz/300Hz
TS-660 - 2.4KHz/1.8KHz/500Hz

The AM and wide RTTY filters in each were left out but you should be able to detect a trend where the SSB and CW filters are concerned. Mind you, there are many different bandwidths to choose from (thanks to OEM and Inrad, Sherwood, etc) for several of these rigs but the combinations listed above are what works best for me.

A lone exception is with the TR7. I would look into putting a Sherwood 2.8KHz filter into place of its stock 2.3KHz filter then moving the latter into one of the accessory filter slots...on a 'phone-only rig, that is. Then load the other slots with 4KHz and 1.8KHz filters. The Sherwood unit has steep enough skirts that you won't bother nearby operators and you shouldn't need an EQ or similar processing gear to sound good.
04-11-2013, 06:58 AM
KB3LAZ

Quote:

Originally Posted by KJ3N

Get the 1.8khz for SSB contesting. Between that and the stock 2.7khz, you're covered for SSB.

You don't want my opinion on ESSB.

You can get the 250hz for CW, but if you ever do any RTTY (which I do occasionally), I think a better compromise would be the 400hz filter. JMO

I would rethink your decision on the DVR. For SSB contesting, you're going to need it.

A second RX comes in handy for DX chasing, but I would wait until you've had some time in the chair with the radio first. I waited about a year before I bought the 2nd RX.

YMMV

Jim, do you have any extra filters slotted in the second RX? Seeings as contesting will be a new venue for me, I am unsure which way to go here. I have done some research and it seems that the second RX even on the $6000+ rigs only have filters slotted to the main RX. Now, I am sure that adding filters to the second RX will give an advantage but the question is how much of an advantage. From my understanding, you are basically using the second RX for spotting.
04-11-2013, 09:16 AM
KJ3N

Quote:

Originally Posted by KB3LAZ

Jim, do you have any extra filters slotted in the second RX?

Only the standard filter in the 2nd RX. I thought about adding filters, but given my operating style and amount of time I'm ever on the air (almost only contests at this point with occasional DX chasing), I didn't see the point. I am not a "hard core" ham in any sense.

Quote:

Seeings as contesting will be a new venue for me, I am unsure which way to go here. I have done some research and it seems that the second RX even on the $6000+ rigs only have filters slotted to the main RX.

My contesting operations are almost always S&P. I make frequent band changes as well. A 2nd RX in that circumstance isn't very useful, IMO.

Quote:

Now, I am sure that adding filters to the second RX will give an advantage but the question is how much of an advantage.

Matching filters in the main and 2nd RX (from my understanding) is primarily used for diversity reception, requiring 2 antennas. That's almost always a weak signal situation when hunting DX, not a contesting situation where it's rare to have signals that weak.

Quote:

From my understanding, you are basically using the second RX for spotting.

In a spotting situation, you would just swap the VFOs to work a station (or band), and then switch back. At least that's how I would approach it. Ron may have a different opinion on that. That's hard core contesting stuff IMO and I don't do that. I'm a very low key contester.

As always, YMMV.
04-11-2013, 09:42 AM
KB3LAZ

Quote:

Originally Posted by KJ3N

Only the standard filter in the 2nd RX. I thought about adding filters, but given my operating style and amount of time I'm ever on the air (almost only contests at this point with occasional DX chasing), I didn't see the point. I am not a "hard core" ham in any sense.

My contesting operations are almost always S&P. I make frequent band changes as well. A 2nd RX in that circumstance isn't very useful, IMO.

Matching filters in the main and 2nd RX (from my understanding) is primarily used for diversity reception, requiring 2 antennas. That's almost always a weak signal situation when hunting DX, not a contesting situation where it's rare to have signals that weak.

In a spotting situation, you would just swap the VFOs to work a station (or band), and then switch back. At least that's how I would approach it. Ron may have a different opinion on that. That's hard core contesting stuff IMO and I don't do that. I'm a very low key contester.

As always, YMMV.

Thanks. I was thinking as much.