Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: Prev 1 [2] 3 Next   Go Down
  Print  
Author Topic: CW Signal Width, Beginner Question  (Read 11200 times)
K6JCR
Member

Posts: 12




Ignore
« Reply #15 on: February 23, 2011, 10:02:10 AM »

Thanks for the help everyone, I'm so glad I asked this question, I was miserable.  It brings up a few more questions, regarding:

the bands are usually not that crowded where the casual slower speed code lives (<20 WPM).

Where do the slower speeds "typically" live?  My current antenna restricted housing only allows me room in the attic for a 20M dipole.  I am tuning from 14.025 to 14.065, above that seems the digital area.  And where I'm tuning(without a filter obviously), I often get either other people's signal or bad background noise.   If there is a home for us slower speeds, especially the learning folks, I would like to know.  I was so frustrated with 20 that I pondered trimming my antenna hoping for a less "popular" band.  But now I know... filter filter filter.

Also, how far away should I stay away from other signals, is 500Hz enough for courteous operation?

Sorry for the direct slam on the rig.  I am sure it is great for what it is.  I myself have found it to be difficult for a first time ham with no elmers.  To learn everything you need to learn, including CW itself, using a 5 watt 817nd without a filter and being your one and only one rig?  That is truly an amazing feat.  If I had to do this over again, I probably would have chose something else.  I would recommend it as a second rig.
Logged
KE4JOY
Member

Posts: 1384




Ignore
« Reply #16 on: February 23, 2011, 10:37:01 AM »

The 'home' for slow code seems to be the low end of the 40 meter CW band (just above the extra portion).

But just about anyone will QRS for you on any band if you ask.
Logged
AE4RV
Member

Posts: 963


WWW

Ignore
« Reply #17 on: February 23, 2011, 11:43:27 AM »

Yes, 40M is has more places for slower ops, like between 7.030-7.060 and 7.110 - 7.120MHz.

But, you are currently only on 20m. Sounds exactly like me when I started out in '96. I didn't have money for an HF rig for a while so someone lent me a 20M MFJ QRP radio which put out about two watts. Someone else helped me build a 20M dipole (still use it) and that's all I had for a while. I found that below 14.040 was pretty intimidating for a newbie but could often find slower folks above that, especially from 14.050-14.060MHz.

Now is a good time to get started on 20M - the days are getting longer and the sun is getting stronger.

Try to add 40M to your antenna situation (random wire and radials? a loop?) and also, 10 and 15 which will be smaller dipoles than your 20. You might not have room for a proper 40M dipole (I don't).

For inspiration:
http://home.windstream.net/johnshan/index.html

http://naqcc.info/

http://www.fists.org/

http://www.k2zs.com/antenna.php

http://jq2uoz.blogspot.com/2010/01/dxcc-qrpp-500mwdipole.html


Have fun!
Logged
AA4N
Member

Posts: 111




Ignore
« Reply #18 on: February 23, 2011, 02:15:47 PM »

Hi John,

It sounds like the guys are giving you good numbers.  I'm guessing that the stock filter on your 817 is 2.4KHz  This is a good filter width for SSB.  It's a little wide for CW, but not unuseable.  It is entirely possible to copy one guy among many by listening for the one pitch that you are interested in and ignoring the others.  However, it does add a level of difficulty.

Some of the guys have suggested the narrower filters (like 300Hz).  Personally, I find that a 500Hz filter is a better all around filter for CW use.  I use 500Hz 95% of the time, and only drop to a 250Hz narrow filter in a few specific circumstances.  A too narrow filter is a bad thing if you are calling CQ.  You could miss a guy that is answering you even if he's just off zero-beat by a couple-hundred Hertz.  Also, if a guy is running older gear, some of them can be a bit drifty.  I love to work the old tube rigs, but sometimes you have to chase them around the band a bit with the RIT control.  This would be harder to do with a really narrow filter.

So, anyway, If I could only have one CW filter, it would be a 500Hz filter.  Just thought I'd weigh in with that Smiley

73

mike AA4N
Logged
AE4RV
Member

Posts: 963


WWW

Ignore
« Reply #19 on: February 23, 2011, 02:23:31 PM »

If my stock bandwidth on CW was 2.4KHz then I would also go for the 500 since I would be using it almost constantly. Since most of my radios are between 800 and 1200Hz on CW without an extra filter, I find that I don't need them so often. Good point, Mike.

73, Geoff
Logged
K8AXW
Member

Posts: 4002




Ignore
« Reply #20 on: February 23, 2011, 05:58:59 PM »

K6JCR:  Let me suggest something.... understand though, I'm not advocating or recommending this product....just suggesting you check it out.

Go to idiompress.com - http://www.idiompress.com/scaf-1.html - and look at the SCAF-1.  It is an adjustable audio filter.  Looking through the information you will find several .wav files for you to listen to.  They will show what this filter will do.  It seems a great deal cheaper than buying a fixed filter for your rig.

I use an old Kenwood TS-830S with both CW and SSB filters.  While both do a good job, I am seriously considering scarfing up the bucks to buy the SCAF-1 just to eliminate a lot of background noise.

As I said, "just a suggestion."

Logged
VA7CPC
Member

Posts: 2414




Ignore
« Reply #21 on: February 23, 2011, 11:00:53 PM »

You should try and listen to both the 500 Hz and 300 Hz filters.

Narrow filters tend to "ring" -- the narrower, the more ringing.  It's hard to describe the sound quality.  _Really_ narrow filters (< 250 Hz) can be fatiguing to listen to.

There is _no_ problem with fatigue with the 500 Hz filter on my FT-817.  I have a 350 Hz filter on my IC-706, and it's also fine to work with, but you are aware you're listening to a narrow bandwidth -- like listening to a signals coming down a long tube, with a very distinct resonant frequency.

Neither one will be a mistake.  _No_ CW filter will be frustrating, a lot of the time.  [I agree with the post that says they should be "stock".]

                 charles

Logged
STAYVERTICAL
Member

Posts: 875




Ignore
« Reply #22 on: February 24, 2011, 03:00:18 AM »

As both a CW and Digimodes operator using an FT817ND, I would suggest the 500hz filter would be best.
The reason is that many digital modes use 500hz as a common bandwidth, and a 300Hz filter would not allow you to use these modes.
Olivia for example uses 500Hz widely, although you can switch bandwidths, you will have problems copying the common 500Hz mode CQ.
I find the 500Hz filter is fine with CW, as with practice you will be able to tune out other signals in your bandwidth, although as
a beginner I recognise it makes it more challenging.
The difference between the 300 and 500Hz filter is not huge, but if you operate digital modes, the convenience of having the
500hz filter will make a big difference.
Having a narrow I.F. filter will also improve your signal to noise on both CW and digital modes and you will be amazed at how the
general noise level goes down, while the signals stay the same.
You could of course use a few capacitors and resistors to build a simple passive filter to put in line with earphones, but the I.F. filter
is by far the best course.
Another option, which I use, is to use a PC as a DSP filter.
There are many free programs which allow you to input audio on the microphone port and output to the headphone port on the PC.
Two that I use are BruniFilt and DSPfilt, both of which allow you to adjust the audio response from 10hz to 3Khz and also use
notch and peaking filters and many other types of filtering, as you would expect from a PC solution.
Cost is zero, and they work brilliantly.
Alternatively, download Simon Browns DSP-RADIO application and just use the filters on that with a PC. Again free.


As regards bandwidth - bandwidth is generally dependent on information throughput, so the faster you send the higher the bandwidth.
Other factors can make it worse such as having poor waveform shaping, but in the end this just means you will have to produce
harmonics of the keying rate to produce that poor shape.
Lots of time and energy has gone into reducing the effective keying rate in the computer and network industries, so they can
send more data on the same media, but in the end information theory as defined by Claude Shannon defines the limits to
sending information over a particular bandwidth.

The FT817 is a great rig, and for those of us who became hams by taking apart old world war 2 surplus tank and aircraft radios,
I can attest that such a rig was an unimaginable dream in those days.

Welcome to CW and best 73s.

« Last Edit: February 24, 2011, 03:16:56 AM by STAYVERTICAL » Logged
KC9TNH
Member

Posts: 304




Ignore
« Reply #23 on: February 24, 2011, 06:26:09 AM »

Thanks for the help everyone, I'm so glad I asked this question, I was miserable.

Where do the slower speeds "typically" live?  My current antenna restricted housing only allows me room in the attic for a 20M dipole.  I am tuning from 14.025 to 14.065, above that seems the digital area.  And where I'm tuning(without a filter obviously), I often get either other people's signal or bad background noise.   If there is a home for us slower speeds, especially the learning folks, I would like to know.  I was so frustrated with 20 that I pondered trimming my antenna hoping for a less "popular" band.  But now I know... filter filter filter.

Sorry for the direct slam on the rig.  I am sure it is great for what it is.  I myself have found it to be difficult for a first time ham with no elmers.  To learn everything you need to learn, including CW itself, using a 5 watt 817nd without a filter and being your one and only one rig?  That is truly an amazing feat.  If I had to do this over again, I probably would have chose something else.  I would recommend it as a second rig.
Hey John, still getting the benefits out of your great question. Smiley  Here are some thoughts - not necessarily in order - from another newbie with an 817nd, and Elecraft T1, and a J-37 key.
(Caveat: I knew going in that the 817 was "not recommended" as a first rig, but I will be so much portable when the winter breaks that it was a driving factor. For the winters in the physical QTH, I may at some point just add a 45w amp to it, and many seem to recommend that THP 45w job you have. I'll mount it on the other side of the tuner 'cause there's no way I'm jeopardizing my precious T1, interface cable or not.)

My first CW contacts all turned out to be very generous Elmers who either answered me & immediately downshifted, or who'd called CQ at 5wpm in a traditional slow area because, well, that's how they roll, helping new operators, and they got a bite from me & reeled me in. In succeeding weeks I appreciated their gestures more  because with them I got to listen to (and practice copying) good spacing. Have found I can copy a bit faster with good spacing, than from someone at my speed but who has everything sounding like a continuous string. (might be a character flaw, but outside written & spoken English I've learned to detest the comma...)

There are net lists that can be downloaded to give a good cross-section of where the traditional slow-speed nets are; some for traffic handling, some for just practice, and many others hang out before/after the nets because it's just a good place to meet keys of similar horsepower. Here's just one example I found:

http://www.fists.org/slownet.pdf

In my neck of the woods I've found that some of those frequencies (the slo-nets in the 7030-7065 area) are unavailable during popular evening times because of the faster/stronger keys (but the 500Hz filter going on order is probably going to keep some of that adjacent stuff away). On 40m 7100-7120 is often a good area in the evening. I've also made contacts at 80m in the 3555 area, as my 50' wire (with 50' of counterpoises along the flower-bed below) that loads up dead-bang for 40m or 20m isn't a bad quarter-wave for 80 under the right conditions. I will have to give 20m more of a try; sadly I expected to see more activity in the CW area opened up for Techs at 15m but don't hear much activity. Could be it's something I need to learn about 15m and why or why not it's currently conducive to traffic.

The fun thing I've had to remember is that when I'm not hearing anything, there could be someone just like me out there... not hearing anything, so I should call. I sat there a couple of nights ago just looking for someone to copy and 'listening to the quiet' when finally someone slowly & clearly called CQ - and promptly had his own pileup from others out there along the wall waiting for someone to ask them to dance. Talk about catastrophic success!  Grin

Also, one of the early-contact Elmers related to me that sound from a key set a bit lower in pitch is both easier to listen to and can sometimes seem to 'cut' through better than a higher pitch. Don't know for certain, but my ears like it alot better.

Well, I promised to attempt some comms with some guys on SSB Saturday morning at 1600Z... I'll give a listen before that from about 1430Z or so if you're in the area of the 20m freqs you mentioned give a call. You're the one with the "big" amp and I'll be listening with my stock 817. That would make a nice couple of dots on the map.  Grin
Logged

73
Wes -KC9TNH
"Don't get treed by a chihuahua." - Pete
VA7CPC
Member

Posts: 2414




Ignore
« Reply #24 on: February 24, 2011, 09:24:07 AM »

To find out what narrow filters sound like . . .

. . Download and install a copy of "CW Get", a CW-reading program.

. . Connect your rig's output to the Mic or Line-In input to your computer's soundcard.

. . When you start CW Get, go to "Filter | Sound Output . . . "  and select the bandwidth you want to listen to.

The sound coming out of your computer's loudspeaker is, roughly, what your rig would sound like with that filter bandwidth.

The "Filter | Main" bandwidth option sets the filter bandwidth that CW Get uses to do its own decoding.

There are lots of free "DSP filter" programs -- you could do the same thing with any of them.

[A narrow DSP filter in the computer is _not as good_ as a narrow IF filter in the rig.  With the computer-based filter, a strong interfering signal inside the IF passband, but outside the DSP passband,  will activate the rig's AGC, and the desired signal will be affected.  With a filter at IF, the AGC won't be affected.]

 
                     Charles




Logged
VA7CPC
Member

Posts: 2414




Ignore
« Reply #25 on: February 24, 2011, 09:27:56 AM »

Google "QRS frequencies" for a list of where slower CW ops tend to congregate.

If you're really frustrated with QRP,

. . . a) you're not alone,

. . . b) I wrote an article after _I_ got frustrated with QRP, with some operating hints that helped me:

http://www.eham.net/articles/23600

The "comments" are probably worth more than the article; QRP'ers are a very enthusiastic bunch of people.

               Charles
Logged
KC9TNH
Member

Posts: 304




Ignore
« Reply #26 on: February 24, 2011, 10:06:03 AM »

Charles, thank you very much for that.
You covered the other thing I'm in process of doing & that will be a classic dipole outside, doable even in at my town location.

Short digression:  I read here awhile back about one's "disease" being evidenced by the tendency to evaluate all natural & man-made structures in terms of their antenna potential. Well, folks, I must now agree.

The other day I was just standing on the edge of the property by the driveway and my bride of some decades noticed my head going back & forth. I was mentally drawing a line between the upstairs BR window and a pair of robust maple limbs; one in the backyard, one in the front, each about 35' from said upstairs BR window. (You're tracking now, right?)

She jerked me out of my reverie with "what are you looking at?"
An unspoken thought collided with my need to verbalize a response and what came out was "it'll just be tired."

"What's tired?"
"The dipole; the wire."
"What wire?"
"Well, it won't be an inverted-V, and it really won't be a collapsed dipole... it'll just be, uh, normal, but maybe just a tiny bit, uh...."
"...tired?"
"Yeah."
She shook her head and went back in to take the cookies out of the oven.

Is there medication for this?
Logged

73
Wes -KC9TNH
"Don't get treed by a chihuahua." - Pete
K6JCR
Member

Posts: 12




Ignore
« Reply #27 on: February 24, 2011, 11:05:22 AM »

Wow, everyone.  Thanks so much for the useful information I've gotten out of this thread.  The internet, my elmer.

One thing I don't think I've seen an answer to:  once I get my filter, what's a good distance to keep away from other signals, is 500Hz considered generous?

One more question:  I understand how to zero-beat my radio based on the sound(like tuning a guitar), but I also see that I can change my CW pitch.  The default is 700Hz.  If I zero-beat to whatever pitch I am set to, am I still on the same frequency as the other station?

Here's my takeaways so far:

1) There's more QRS on 40 than 20.   I will work on figuring out random wire antennas.  I stayed away from that option because the ARRL Low Power Communication book described them as "mediocre performance" and I felt I was already too challenged with QRP, learning, and perceived congestion(no filter).  I had a lot of fun learning to build my 20M dipole and it didn't require a tuner, which I don't have.  Will work on that too.

2) In the meantime, I plan to park it between 14.050 and the QRP frequency 14.060, per the suggestion to search for QRS frequencies came up with http://www.omen.com/ham/qrs.html

3) I also do PSK31, so I am leaning towards the 500Hz filter based on that suggestion.

Thanks again!

73's

John
K6JCR
Logged
N5EP
Member

Posts: 6




Ignore
« Reply #28 on: February 24, 2011, 11:30:07 AM »

Before you order any product based on recommendations in this thread, you should not only check out the product review for it in eham's Reviews community, but also check out eham's "Company Reviews" in the Forum community and evaluate for yourself what is said about any company you are considering ordering from.  You might avoid a nightmare.

(This post is not meant to provoke a discuss about companies in this thread.  Just a word to the wise . . .)

Steve, N5EP
Logged
KC9TNH
Member

Posts: 304




Ignore
« Reply #29 on: February 24, 2011, 11:50:54 AM »

One more question:  I understand how to zero-beat my radio based on the sound(like tuning a guitar), but I also see that I can change my CW pitch.  The default is 700Hz.  If I zero-beat to whatever pitch I am set to, am I still on the same frequency as the other station?
Pretty good discussion about pitch here:

http://www.eham.net/ehamforum/smf/index.php/topic,72369.0.html
The first answer given is not a bad one...
 Wink

Just my personal observation (having changed the default pitch on my 817 to 400 or 450Hz, forget which) is that the lower pitch is not only more pleasing to my ears, for some reason I can also more quickly detect that nice 'ring' when I'm right there. My particular procedure if not already tuned on that band on the 817 is to enable the BK, go off a bit from any known traffic, get a match from the tuner, disable the BK for the key and listen. I can then use right-hand key (my sidetone) and left-hand dial to quickly and precisely nail someone I'm interested in. The key Break menu item is still under the B key, so if I want to talk I just push the B key and begin transmitting. Use of a spot tone might be more intuitive for you, as I'm heavily right-handed.
Logged

73
Wes -KC9TNH
"Don't get treed by a chihuahua." - Pete
Pages: Prev 1 [2] 3 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!