QRL procedure

[KB8WFH]

A minor vent here. I have been encountering more and more problems with CW QSO's moving in right on top of my exiting QSO. What's the deal?

I was on a frequency and I heard QRL? on less than 1/2 Kc higher. I responded with "Y". 1/2 second later, I get a QSO starting between two other stations, each station is 10db past S9 and wiped out my QSO.

#1 - Don't bother send "QRL?" if you don't really care if there's someone there or not.

#2 - If you do care, send it then LISTEN LISTEN LISTEN! Then send it again and listen some more! Don't send QRL? then immediately start sending a split second later. NO WAY both of these stations couldn't hear me.

I can hear both of them blasting out my speaker, but they can't hear me? The prosign for that is "BS - Bravo Siera." I get tired of the "diode propagation" argument.

OK, back to the key...I'm cool now.

73'

[w8znx]

Hello Matt
nice qsl card

I don't send y #heck had to think what y meant

I send C

often run older receivers hear real strong QRL
3 or more kc away know im sol
better crank on the cans tight and close my eyes

some ops have the rf gain turned down
and the 250 cycle filter dialed in

heard about this the other day

op I know was in a nice rag chew on 20 cw
we will call this station # #1st station

3 rd station comes along sends qrl ?
1 st station sends C C C
3 rd station sends qrl agn
1 st station sends c c c qsy de WXX7X
3 rd station sends WXX7X WXX7X de WXX8X
tnx fer the call ur rst is

kinda makes you think they will let anybody
use a telegraph key #hi hi

mac dit dit

[al7n]

Ya...

It is a problem when folks don't switch out the tight filters so they can hear what is going on around the band.
They just listen to a little 250 Hz or 500Hz slice and
figger if they don't hear anything, nobody is there....

If yer gonna send "QRL?" better make sure you can
hear up and down from where you are a little bit to make sure nobody is responding "C C" or "Y" or whatever.

http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

[AG3Y]

Can beat the CW stories with some of my own! The new breed of SSTV operators will get on 14.230, the traditional analog calling frequency, and start sending pictures, one on top of another.

I have a very modest setup here, only a loop antenna at about 30 feet, so I cannot "rotate the house" to favor one station over another. But you would think that several of these stations that are sending their own video "CQ"s could probably see one another's transmissions, if they were only half-trying !

Occasionally, one Old Timer with a truly outstandingly strong signal will get on and attempt to get an informal net going, but many of the other operators on frequency will have nothing to do with it. They just keep sending their own video, no matter who may be actually transmitting a picture to whom !

Frustrating, and very poor operating procedure, to say the least ! http://www.qrz.com/iB_html/non-cgi/emoticons/mad.gif

73, Jim

[kr2d]

Quote[/b] (al7n @ Feb. 09 2006,20:17)]It is a problem when folks don't switch out the tight filters so they can hear what is going on around the band.
They just listen to a little 250 Hz or 500Hz slice and
figger if they don't hear anything, nobody is there....
So how far away is reasonable? CW is a narrow bandwidth mode, we don't want space QSOs apart by 3KHz. On the other hand, not everyone has DSP IF with 50Hz filters. Is 1KHz enough? Even that seems a waste of bandwidth to me.

Be aware that on some rigs, like my old FT-301, you don't have a choice of narrow or wide filters for each mode. You get a wide filter (2.4KHz) filter on SSB, and a narrow one (e.g., 250Hz) on CW, if a CW filter is installed. So if I'm using CW on that rig, I'm only going to hear a small slice of the band unless I switch to SSB after sending "QRL?". I'm likely to miss a "C" by the time the mode switch is accomplished.

[G8ADD]

It's a shame so few rigs have a decent notch filter (maybe some ops don't know how to use them?)

73

Brian G8ADD

[N5PVL]

Not everybody has a narrow CW filter, or the money to order one. I don't think it is really safe to assume that everybody working CW has a narrow filter, nor is it reasonable to expect them to.

New guys especially are likely to be out there seeing what they can do with what they have, and one responsibility on the old-timer's part is to see to it that those first tries are good experiences for the new guy, so he'll come back - and maybe get a narrow filter, dang it!

I used to work CW stations every day and you can be sure that I had a narrow filter back then, but it's been years since I've touched a key and if I decided to get back into it now, I can guarantee that it would be with the filtering I have, while I try it out and decide if I enjoy it enough to justify a C-note for another narrow filter.

I think AI4CB's suggestion about looking around within a wider passband and then going to a narrow filter once you are dialed in and know you're in the clear makes good sense. It sounds like good, sound operating procedure to me.

You can never go wrong by being considerate of your fellow ham.

[W8JI]

Quote[/b] (n2jso @ Feb. 09 2006,21:20)]Quote[/b] (al7n @ Feb. 09 2006,20:17)]It is a problem when folks don't switch out the tight filters so they can hear what is going on around the band.
They just listen to a little 250 Hz or 500Hz slice and
figger if they don't hear anything, nobody is there....
So how far away is reasonable? #CW is a narrow bandwidth mode, #we don't want space QSOs apart by 3KHz. #On the other hand, not everyone has DSP IF with 50Hz filters. #Is 1KHz enough? #Even that seems a waste of bandwidth to me.

Be aware that on some rigs, like my old FT-301, you don't have a choice #of narrow or wide filters for each mode. #You get a wide filter (2.4KHz) filter on SSB, and a narrow one (e.g., 250Hz) on CW, if a CW filter is installed. # So if I'm using CW on that rig, I'm only going to hear a small slice of the band unless I switch to SSB after sending "QRL?". #I'm likely to miss a "C" by the time the mode switch is accomplished.
The typical modern CW transmitter has an actual bandwidth of about 1kHz. That because they use poor shaping and a rise and fall time that is too fast.

If you send two WPM or 80 WPM, the overall bandwidth remains the same since it is set by the rise and fall times and shape.

Keyclicks (http://www.w8ji.com/keyclicks.htm)

The receiver bandwidth varies with the filters used, but 500 Hz is probably a reasonable value. Of course signal levels have a lot to do with it.

This probably means we should be concerned about people maybe 1kHz away using good gear and further away when using poor gear, especially if signals are strong and noise is low.

I try to avoid operating closer than 1kHz to other people but that varies with how crowded the band is. If the band is empty I like to stay 3-5kHz away. If the band is pretty full I might get as close as 1kHz. I try to never get closer than 1kHz, although in periods of heavy activity that is impossible.

By the way, some of the very worse rigs for operating close are DSP based radios. Using 100Hz filters the radios have a close spaced dynamic range of maybe 30-40dB. Older radios with crystal or mechanical filters are often up in the 50-80dB dynamic range for close spaced signals.

A radio might have 2000 filters that go down to 100Hz and work worse for close-spaced signals than a 1980's radio with a single 500Hz filter.

73 Tom

[WA2ZDY]

It would be nice if everyone on CW had a 500 Hz filter. But they don't. I do but haven't always. On an old Hammarlund, you can crank in as much crystal filter as you want, QRM 500 Hz away is going to cause trouble.

If you want to park 500 Hz away from soemone, fine. Give a QRL? on the frequency then listen. If the guy 500 Hz away doesn't answer up, you can assume you're not bothering him. If he does, have the decency to move. And of course when you call QRL? or CQ, you should tune around and see if someone answers you a little off your frequency too. You never know who/what you might be missing keeping the blinders on.

[n8yx]

Another thing to consider is that some ops tune to the wrong side of zero beat (thank you RIT...) when listening for replies to their "QRL?".

As several others have mentioned, I also keep the wide filters engaged when listening for activity, then switch to narrower ones as the situation demands. Rarely if ever will I call CQ without going "wide" to check nearby frequencies first.

[w8cbc]

Speaking only from my own limited experience thus far...

I used to assume that if I heard nothing in response with the R392 (minimum BW is 2 kc but the shape factor isn't exactly vertical, I can hear quite a bit more) after two "QRL?"s, I was good to go. However, I've gone ahead and started up only to realise later that there was someone zero-beat with my BFO. Oops. So I tune around a bit anyway now.

As to the 751A with its much better filtering, aye, I can switch to "wide" (SSB filter) but it mostly passes one sideband so I could still be interfering with someone in its shadow if I don't spin the VFO a bit to check.

I'll add that when tuning up, we should (and I do) send "test de (callsign)" after QRL-ing. What the hey, aside from the common courtesy aspect, it's got me a couple of contacts.

[w8wlc]

The other morning I am on 40 working a station, another comes on about 500 hz higher and sends QRL? I reply C no sooner get the C sent then this wonder starts calling CQ. He gets a answer now he is complaining about QRM coming on frequency go figure. I remember when all it took was to send the old american telegraph C ditit dit to find out if the frequency was busy a response of ditit or C means its in use. You gotta love the SSB ops thought QRzed the frequency is the frequency in use? Instead of just saying MYCALL freq busy? Leave it to a ham to waste more time communcating with a dozen words when one or two will do.

[kr2d]

Quote[/b] (w8ji @ Feb. 10 2006,08:01)]By the way, some of the very worse rigs for operating close are DSP based radios. Using 100Hz filters the radios have a close spaced dynamic range of maybe 30-40dB. #Older radios with crystal or mechanical filters are often up in the 50-80dB dynamic range for close spaced signals.

A radio might have 2000 filters that go down to 100Hz and work worse for close-spaced signals than a 1980's radio with a single 500Hz filter.
My IC746Pro has a blocking dynamic range of 100dB with 5KHz spacing and 500Hz filter at 14.02MHz, according to the ARRL Lab tests.

I don't know how that compares to measurments of the best crystal filtered rigs under the same conditions (too lazy to do the reasearch). I do know that the '746Pro, set at 250Hz, filters better and has less ringing than my FT-301D with 250Hz InRad filter.

I'd like to see blocking dynamic range measurments with signals spaced at something like 1KHz. Have any such test reports been published? That would show how rigs perform under real CW conditions.

I agree about the keyclicks. Some stations have bad clicking. I've heard clicking as far +/- 1KHz from the carrier. Even a 50Hz filter can't get rid of them, since they are partially in the passband. I'll adjust the rise/fall time on my '746Pro to 8ms to reduce clicking as much as possible.

Back to the topic, on CW, I tune around with a 1.2KHz filter, and go to narrower filters only if needed. I'm just getting back into CW after 20 years (practicing getting my code speed back up), back then I ran an HW-101 with no CW filter in it. Hence, my earlier question about how far is reasonable to call QRL or CQ from an ongoing QSO. I think I'll go with the 1.2KHz filter for calling QRL, and if I can't hear anything, assume it's OK to proceed.

For what its worth, PSK31 QSOs are often spaced at 100Hz or less when the band is crowded, and it works out just fine. During the RTTY Roundup, I successfully worked RTTY stations separated by just 250Hz.

73,
-Ron N2JSO

[KB8WFH]

Just to let you know, I was using an FT-100D with my CW QSO. Yes, I can switch to a narrow filter, but it sounds terrible. No reason anyone, especially on 75/80 meters needs to be anywhere NEAR another QSO.

[K9STH]

WFH:

On a Wednesday evening your statement about QRM probably has some value. But, on weekends, and especially during a major CW contest, then you are going to have to use a narrow CW filter whether or not you really like to use one.

Either that or, like the "olde tymers" had to do with the 8 KHz wide receivers that were the norm back in the 1940s well into the 1960s, and that is to develop a "cerbreal filter". That is, learn how to ignore the other signals even though they are booming through.

Someone mentioned the receiver R.I.T. being tuned to the "wrong" side of zero beat. Actually, there is no "wrong" side. You really need to tune to both sides of the zero beat because you may be interferring to someone that is either above or below your transmitting frequency.

It is possible to kill the AGC/AVC, kill the receiver preamplifier, turn the audio gain up and then use the r.f. gain as the volume control when receiving CW (works on SSB as well). You will be suprised at how much better you can receive the desired signal without much of the QRM that you were experiencing.

Too many amateur radio operators don't have a real "clue" as to how to operate their receivers (and transmitters as well). I suggest taking between 15 minutes to an hour just tuning around a crowded band and trying different settings. You will be amazed at the things you can do to improve the reception. Your "S" meter may not even be moving, but the station that you are communicating with will often be "Q5".

Glen, K9STH

[w8znx]

Quote[/b] (n2jso @ Feb. 09 2006,21:20)]So how far away is reasonable? #CW is a narrow bandwidth mode, #we don't want space QSOs apart by 3KHz. #On the other hand, not everyone has DSP IF with 50Hz filters. #Is 1KHz enough? #Even that seems a waste of bandwidth to me.
ahoy maties

even with modern gear seldom use narrow filters
find it easer to hear with a 2.8kc filter
than with a 500 cycle filter
most of the time a bit of qrm dsnt bother me
when it does its time to punch in the filters

how much space depends on band and time of day
when there is lots of space use it

enjoy running old gear
often using receivers are not very selective
some of my transmitters drift

3 kc is not too wide a space when running
some of my old gear
in fact try for 8 or 10 or even 12 kc
you do not want to be near my freq
if im running the TNT job
when the line voltage changes
or the antenna starts to move in the wind

only use old gear during non peak hours
it would be foolish to run them on
40 meters at 0300 gmt

but 80 meters, 0800 hours gmt
I do hope that some op will not decide to use
a freq with in 3 kc of me
often try to find space with 10 kc or more room

so its 3:30 am week night
there are a few dxers down in the bottom 25 kc
a station or two around 3530, 3534
I am on 3547 no other stations with in 15 kc
some bumpkin decides to fire up on 3549

happened few weeks ago
transmitter was still cold
just let the old girl slowly drift
up to his freq
I know should not have
but heck it was fun the hear him howl about
my drifty signal

do not expect lots of space
only some common sense

mac dit dit

[W8JI]

Quote[/b] (n2jso @ Feb. 10 2006,12:14)]Quote[/b] (w8ji @ Feb. 10 2006,08:01)]By the way, some of the very worse rigs for operating close are DSP based radios. Using 100Hz filters the radios have a close spaced dynamic range of maybe 30-40dB. #Older radios with crystal or mechanical filters are often up in the 50-80dB dynamic range for close spaced signals.

A radio might have 2000 filters that go down to 100Hz and work worse for close-spaced signals than a 1980's radio with a single 500Hz filter.
My IC746Pro has a blocking dynamic range of 100dB with 5KHz spacing and 500Hz filter at 14.02MHz, according to the ARRL Lab tests.
A 5kHz spaced measurement is next to useless in evaluating a receiver's performance.

Let's look at 40 meters and see what happens. An IM3 DR test at 5kHz spacing would put one signal at 7.000, another at 7.005, and you would be listening at 7.010 or at 6.995.

There aren't many radios bothered by a signal that far away!! Manufacturers LOVE those wide spaced tests, because those tests don't test anything except the first mixer. The numbers look great, but the test is a nearly useless test of just a few stages. It doesn't check the DSP system at all.

5kHz isn't even a good SSB test spacing.

To accurately reflect receiver performance on CW, the test has to be at 1kHz or less spacing. A 1kHz test would be with an interfering signal at both 7.000 and 7.001, and you listening on 7.002 or 6.999.

Sherwood Receiver tests (http://www.sherweng.com/table.html)

shows 2 kHz tests

My receiver tests (http://www.w8ji.com/receivers.htm)

shows my tests if you follow links.

Both give a better test spacing for CW, and a very good one for SSB.

You'll see the 756Pro ranks about 25th on Sherwood's pages. Typically DSP-only radios have dismal close spaced dynamic range. They are marginal at 2kHz spacing, and fall apart quickly as spacing is made closer.

If you want to dig out a very weak signal near some strong signals, better not have a DSP-filter-only radio.

73 Tom