Microphones, Processors and SSB Equipment Setup and Use

Posted in operating, Radio with tags , on 2012/03/23 by NY4JB

Beyond personal preference there are extremes in setup and microphone use that can range from frustrating to outright illegal. I’ll describe a few of these that I witnessed recently and then describe what I consider to be good practice for effective communications.

The meek operator sets his mic gain low, doesn’t use any compression (processor) and speaks softly; he’s running 100 watts but is only really using 25 watts at best. I heard a fellow in the South Pacific who fit this class; his signal was clear but right at the noise level making him hard to copy. He would end a QSO and several stations would try to work him but when he came back to one several would try again because it was hard to tell who he came back to. He would then get a little ticked and speak up asking for everybody to stand by except for whatever station he wanted to work – during this time his signal was strong and clear, 5-9, armchair copy but then he would fade back into a whisper and back down to S-3 or less. His operation is certainly legal but very frustrating to the folks trying to work him and of course to him as well as he is causing the confusion that is causing him to have to tell people to stand by.

Next is the guy who is splattering 5+kcs in all directions, he sounds fine if you tune to his frequency and he always seems to be parked next to that rare DX or the net operation you’re trying to work. His operation is illegal but he will not listen to anybody because he is convinced he knows what he’s doing and his equipment and operation is not at fault. If you try to tell him that he is splattering he will tell you it’s your receiver and how it just can’t handle his powerful signal. He will sometimes ask the guy he’s working if his signal sounds ok and of course his signal sounds OK on frequency. What he should be asking is for his friend to tune up and down 3kcs and make sure he isn’t splattering but this rarely, if ever, happens. Often this guy is also running excessive power as the guy he’s working just told him he’s thirty over, which is most likely illegal since the FCC rules tell us to run the minimum amount of power needed for communication.

Another is the guy with tons of background noise. Maybe it’s the sound of fans running on high, other radios or maybe it’s just the general noise and echoes from the room he’s in. His signal is pretty good but the noise is as loud as his voice and although his operation is technically legal it makes for tiresome listening. Sometimes this guy is splattering as well which means all of that background noise is splattering too.

So then what do I consider to be correct practice?

Let’s start with the source, the voice itself. You should speak in a consistent, moderately loud voice as if you are speaking to somebody across the room and what you are saying is important.

Secondly, you should be using a communications microphone. I know there are at least two groups of people that disagree with this, the AM folks and those who wanted to be news anchors and are now trying to sound like one on SSB, but the purpose of Amateur Radio is communications not glamour. That being said I will give them a general pass since for the most part they hang out on the same frequencies and have pretty good signals, but definitely not all of them. One problem with using a studio microphone (and I own a recording studio so I have many of these) is that they are broadband and pick up all audio frequencies including those outside of the range permissible in amateur radio; they also don’t have noise cancelling characteristics that are built into many communications microphones so they pickup more background noise than a communications mic. Studio microphones were designed to be used in studios, so unless your station is setup in a nice quiet (no fans), echo free vocal booth don’t waste your money on the wrong type of mic.

Now that you have the right mic, speak into the mic. Don’t hold it a foot from your mouth or sit it on the desk and talk from across the room. The mic should be held to the side of your mouth, nearly touching your lips. The reason you hold it to the side is to prevent your breath from hitting it directly. There are two reasons it needs to be close, first is to prevent it from picking up background noise and the second is for consistency. If you hold it 2 inches away now and 8 inches away the next time there will be a 12dB difference in level, that’s 2 S-units.

Processing: First the legality, the use of any form of echo, reverb, delay, or time based audio processing is illegal on Amateur and CB radio. Also, EQ or the equalizer should be used with extreme caution; remember your SSB signal is limited to a small bandwidth of about 2.8kcs. Also, unless you are singing bass even a deep voice has no content below about 125Hz. So the realistic range for communications is approximately 250-3000Hz. For the most part EQ should be avoided, for example, I don’t have a deep speaking voice but trying to compensate with EQ will not change that but it can introduce odd artifacts that waste power and can even cause interference. Choosing the right microphone will give much better results than trying to compensate for the wrong one with EQ so I suggest that as the primary path if you don’t like what you sound like.

Now for the processing that should be used. First, or actually last in the chain, almost all SSB transmitters have ALC built in which is a good thing. Ten Tec advertises their ALC light as the easy way to know you are hitting the ALC at a good level, if your rig doesn’t have a light it probably has a meter, in which case you should refer to the manual on how to set your level, but even if it doesn’t have either a light or meter you can tell where you stand by using an external power meter – the one built into your tuner is fine and I will describe how to read it a little later.

Compression should always be used; I know there are those that think that processor button should only be used those rare times when you need a little boost but in reality the only times it shouldn’t be turned on is when you are not operating SSB voice mode (digital modes for example) or when you are using an external processor. If you have ever listened to commercial broadcasts of any kind (TV radio, news, DJ etc.) they all use speech compression and probably more than you realize. Now how much processing (compression) is a matter of personal preference. I tend to go fairly heavy because I don’t care if my voice sounds processed I want to be heard clearly but there are those who don’t like the way it sounds a go much lighter trying to find the point where they don’t sound processed but they still have a consistent signal. When standard processing is overdone it can make a signal harder to copy because it wipes out articulation and inflection and levels all sounds (including background noise and breathing) which is why off and on air testing is important. The next step up is the RF Clipper, which works by converting the signal to RF, clipping the peaks, filtering it for proper bandwidth and then converting it back to audio. This is my tool of choice and once setup properly makes a signal much easier to copy under marginal conditions.

Testing and Adjustment
If you don’t have a dummy load you should get one, it is really not right to cause noise and/or interference while setting up your station. It also helps to have a second receiver and portable shortwave radio with a BFO and wide filters and the ability to record the output can be very helpful. Having a computer with an audio spectrum analyzer is also handy, Digipan software can be used if you don’t have any other options. In my case I used the spectral display in Adobe Audition (recording software).

OK let’s get started with your rig hooked up to your power meter and dummy load, if you own an amplifier leave it turned off and you might even want to bypass it completely. Set your mic gain to about 12 O’clock and your power output at full, processor off for now and match the frequency on your rig and receiver. Transmit a few words and fine tune the receiver (headphones are helpful to avoid feedback) so your voice comes back at the same pitch as it normally is. Now say a few words while watching the power meter and note the peak reading and how it is moving. Setup your receiver to record or feed it into your computer with digipan running and transmit a few words noting the bandwidth of the signal that shows up on the water fall display on digipan or your software. There should be nothing below about 150 Hz and nothing above 3000Hz. If you are using a ssb/ham receiver that doesn’t have wide filters you will need to do another test by tuning 3kcs up and making sure your signal is not heard and then tuning down 3kcs and making sure it’s not heard there either.

Now turn on the processor and set the processing control at 12 O’clock and perform the same test again. This time the power meter should move around less but the peaks should be about the same, in other words the average power should be higher. The bandwidth of your signal should still be about the same. Now with the output of the receiver being recorded try transmitting with the processor set to 10 O’clock, 12 O’clock and 2 O’clock – it helps to say where it’s set then say the same thing at each setting, for example “this is with the processor set at ten O’clock this is November Yankee Four Juliet Bravo Testing Five Nine Five Nine at Ten O’clock.” Listen to the recording and decide if you think any of these settings sounds too processed. Then do some more tests to fine tune the setting, for example if you didn’t the 2 O’clock setting was too much repeat the test using 2, 3 and 4 O’clock. Or if 2 was too much repeat using 12, 1 and 2. If you are using an external processor the methodology is the same but you may have more adjustments to try.

Once you find the setting you like best it’s time to set the mic gain. In this step you make sure you’re getting the most out without splattering. Remember we are still using the dummy load, now watch the power meter and transmit while adjusting the mic gain. What you are looking for is the exact point where the peaks on the power meter stop getting higher as you turn up the gain. The first time you do this it will take a few tries and it’s generally better to set the gain slightly low (peaks at say 90 watts) rather than slightly high (peaks at 100 watts but splattering). Now run the receive test and check your bandwidth again, if there’s anything outside the 150-3000Hz range you are overdriving something and need to go back and reduce gain.

The final test is on the air, ideally recording your local receiver and having friends check above/below your signal for splattering (or using internet receivers), and making sure you are not getting RF into your audio. If it all tests are good you are ready to go but remember to recheck often. You may get the occasional comment that you’re over-processing which you should take seriously but think about who it’s coming from, if there signal is of the meek variety they might consider any audible processing as a bad thing, they also might have their RF gain turned all the way up which will add another layer of compression to your signal, etc. so take the comment seriously but solicit reports from others as well. Now, if you are told you are splattering take that report very seriously and retest with the dummy load, reduce your mic gain, Etc.
73

QRP Portable

Posted in 73, diversity, operating, Portable, QRP, Radio with tags , , , , , , , on 2012/03/09 by NY4JB

QRP Portable 1

Working QRP portable from the picnic table at work. And here’s a view showing the kitepole antenna support leaning up against a tree.

Worked All States Type Nets

Posted in Uncategorized on 2012/02/17 by NY4JB

Nets like OMISS, the 3905 Century Club and NATA are a popular and relaxing way to work your way to WAS.  The addition of networked logging and online chat makes these a real social way to spend some time on the air but I often see the same mistakes made repeatedly so here’s my simple guide to being a successful participant.

Listen to Net Control and only speak when spoken to.  That means don’t try to check in when they aren’t asking for check-ins, don’t relay unless asked, etc.

Be an active participant during the net even when you aren’t transmitting.  If you check into the net you are making a social commitment to be at the radio and paying attention to what is going on.  So with the exception of Handihams and mobile stations follow these rules:

Follow the list and know whose turn it is.  Be ready to relay even if you aren’t called upon to do so.  Write down or enter a report for everybody on the list as you hear them (NetLogger makes this really easy).  Know who you’ve already worked.

If somebody goes up for grabs and you haven’t worked them say your call sign once phonetically and then listen.  If you don’t really need to work the station delay a bit and if others respond don’t bother but if nobody does go ahead and work them, it’s not fun to go up for grabs and have nobody come back.

If somebody calls you don’t be the station that delays the net by needing to be woken up.  There will be times when a weak station calls and you aren’t sure who they are calling in which case it’s OK to be silent and wait until NCS lets you know you’re being called but if you can hear that you are being called be ready.

When you get a call repeat their call sign and the report they gave you, then state your call sign and give them their report.

Don’t change the report once you give it, conditions are always changing but reports are only approximate at best so stick with the first one.  One exception to this is when you call somebody that was really weak when you heard them (usually on check-in) so you give them the low report off your list but when they come back to you they give you a 59 and are strong (59 or better) in which case it’s normal to update the report but don’t do it if they are now weaker just stick with what ever you gave them.

If they didn’t give you a report repeat both call signs give them their report and then say something like “How Copy?” or “And what’s my report?”  Then when they give you a report simply repeat the report like “thanks copy five-nine.”

When it’s your turn to make a call you should already know who you want to call, if you are following the list this should be easy.  Don’t wait until your turn to hunt through the list for a state you need.  If you aren’t sure who to call always go up for grabs, never take a pass as there may be somebody on the net that needs you.

When it’s your turn you are the control station so make your call remembering to repeat the report you received and when you’re done say “back to net.”  Don’t leave it hanging.  It’s OK to call a station you haven’t heard and give them a “report on the over” but be sure to do it and give them a chance to repeat it.  Once they confirm it say “back to net.”

If the station you are trying to call doesn’t respond you can ask NCS for help, if it still doesn’t work you can try another station but try not to hold up the net while you fish around for somebody, either go up for grabs or say “no joy, back to net.”

Going up for grabs:  If you decide to go up for grabs make sure the last thing you say is “up for grabs” because once you do stations will start calling.  So, say your call sign, state and “up for grabs.”  Go back to the first call sign you copy with their call sign and a report.

Don’t try to exchange other information on the air during the net, with the exception of real emergency traffic which is rare but still happens.  It’s rude to hold up the net to ask what part of town somebody is in because you grew up there, etc.  If somebody asks you questions that aren’t related to the net you should give a short answer and say we really need to keep the net moving.

Final rule, it’s supposed to be fun, don’t ruin anybody’s fun.  If NCS skips your turn remember he’s human and running a net isn’t always easy.  If there’s a reason to break any of these rules then break them but you may feel bad afterward.

73 and God bless

How to use an antenna tuner

Posted in 73, operating, Radio on 2012/01/13 by NY4JB

Way back when I first passed my Tech-Plus license exams and was waiting for my ticket to come in the mail.  It was back before the internet so you had to wait for the license to come in the mail to find out what your call sign was and get on the air.  I bought a couple of QST magazines at a bookstore (before the internet there were stores that sold books and magazines) and researched which radio to buy and how to setup an antenna.  There was an article that described a 3-band antenna made and fed with ladder line.  So I ordered 200’ of ladder line, an MFJ antenna tuner, an Astron power supply, a bencher paddle/keyer combo and a Yaesu FT-840, all of which put me over budget and arrived before I got my license in the mail.

I got the antenna strung as high as I could up in some trees and got the ladder line run into the basement and got everything connected and was amazed that I could immediately hear strange sounding voices (I hadn’t yet learned how to tune in SSB signals).  And then my license finally arrived.

The fancy cross-needle meter on the little MFJ tuner was sweet and I had an electronics background so I knew I was supposed to get the reflected power as low as possible and the forward power as high as possible but I really didn’t have a procedure to follow and there were no instructions on how to do it.  So I really didn’t have a clue what I was supposed to do but I picked a frequency from the chart that my license class was allowed to use and I fumbled around until I finally got a decent SWR.  Then hands shaking I used my paddles to send CQ, secretly hoping nobody would answer, but then W6DBB came back… Oh wait,  you wanted to know how to use an antenna tuner, I’ll write about my first QSO another time.

First, No-Coax!   You should be feeding your antenna with ladder line or even better directly from the tuner.  If you use ladder line resist the temptation to keep it flat all the way down from the antenna, it is best to twist it.  About one twist every couple of feet will keep it from oscillating in the wind and it will also reduce RF coupling with nearby metal objects like gutters.  Also, try to keep it away from metal objects, it’s not so bad if it crosses close to a gutter but you don’t want it parallel and it definitely shouldn’t touch.  So now you have your random length dipole or preferably a loop antenna hooked to the balanced output on the antenna tuner.  There might be a jumper required depending on the tuner (that info will usually be in the manual).

If the manual has recommended starting points for the different bands, use them.

Is it time to tune up yet?

Almost.  You have probably heard that you should find a frequency that’s not in use to tune up but I take it one step further.  Pick a band that is dead, for example 20, 15 and 10 Meters are daytime bands so they would be good if it’s night, likewise you would work on the lower bands (40, 80 & 160) during the day.  You still want to listen for a couple of minutes to make sure the frequency is not in use, remember your antenna isn’t tuned at this point so you can’t transmit to ask if it’s in use and you are not going to be receiving well yet so you need to listen carefully. Now have a pen and paper handy.

Now that you’ve found a frequency that your license allows you to transmit on and determined that it isn’t in use.  Write down the band and frequency.  If your tuner manual recommends settings for this band/frequency set the tuner controls to those settings, if not set the controls in the middle position.  If the meter has a power level switch put it on the lowest setting.  I’m assuming you will be using a cross needle meter, if not put the switch in the SWR position (you may have to switch back and forth if you need to see the power).  I’m also assuming a standard Capacitor-Inductor-Capacitor type tuner.

  1. Turn the transmit power on your transmitter all the way down; refer to the manual on how to do this.
  2. What you are going to do next is transmit a carrier for a second – use CW mode – watching the SWR meter.
  3. If neither the power or SWR meter moves you will have to turn up the power a little bit just enough to get the meter to move enough to get a reading (refer to the manual that came with your tuner or meter on how to read it).
  4. Stop transmitting and write down the position of the tuner controls and the meter reading just as they appear on the tuner from left to right.
  5. Next change the Inductor setting, one click or one full turn to the left.
  6. Again, transmit just long enough to take a meter reading.
  7. Stop transmitting and right down the reading and control positions.
  8. If the SWR went down (or stayed the same) you will adjust the inductor to the left again and repeat steps 6 and 7 until you find the setting that gives the lowest SWR reading but if it starts to go up you adjust the Inductor to the right until you find the setting that gives the lowest SWR reading.
  9. Now that you’ve found the best setting for the Inductor (at least the best for the moment) you can start adjusting the capacitors.
  10. At this point you will adjust the input (or left) capacitor for the lowest SWR reading by transmitting while sweeping the knob back and forth until the meter dips – if the meter reading was already very low you can turn up the power slightly to help find the best setting.  It should only take a second or two, don’t be too fussy at this point.
  11. Write down the new capacitor setting.
  12. Repeat steps 10 and 11 for the Output (or right) capacitor.
  13. You are now getting close and can start to increase power to help fine tune the settings.
  14. You can now go quickly between the two capacitors (and if your tuner has a roller inductor you can fine tune that as well) trying to find the overall best setting.
  15. Remember to keep your transmissions short and write down your results often.
  16. If your tuner has a switched Inductor and you can’t get a 1:1 SWR reading (where the reverse power or SWR meter doesn’t move at all) you can try adjusting the inductor one setting to the left or right.
  17. Caution, don’t increase power too much (above 10 or at most 25 watts) if the SWR is above 2:1
  18. Assuming you have gotten a low SWR reading and have increased the power to the desired level, usually 100 watts and gotten the best SWR reading possible write everything down.
  19. These final readings are your new starting readings so next time you want to tune up on or near this frequency you will be able to do it very quickly because you will already be close.  You will still want to start with low power just in case something has changed, antennas do tend to fall or break, etc.
  20. Now do the same thing for other frequencies and bands, it may take a couple of days since you will have to wait until the opposite set of bands will be open for your tuning experiments.
  21. Now you have a good chart of starting positions for top, middle and bottom of every band your license allows you to use all you will need to do is fine tune just remember to find a clear frequency and keep your power low while tuning.

Also, if there are any frequencies you use on a regular basis, for nets, scheds, etc., be sure to write down your tuner settings so you will be really close next time you want work on that frequency.

73

-jim

75 Meters… Not for the Faint-Hearted, really?

Posted in 73, diversity, operating, Radio on 2012/01/11 by NY4JB

Or was the offended ham really the offending party?  A lot of bad things are said about the old timers who hang out on 75 meters and it wasn’t so long ago that I was guilty of saying some of it.  These are the folks who meet on the same frequency every night and talk about the same things; they are sometimes called cronies, ‘the residents’ and even ‘potato farmers.’  When I was a new ham I had similar experiences as the one Randy (KJ6JAJ) wrote about in his correspondence “75 Meters: Not for the Faint-Hearted“(QST December 2010 p. 24).   I came upon a group discussion, tried to join the group and it didn’t work; I felt rejected and a little bitter but it wasn’t them, it was me.  I was trying to fit in where I didn’t belong, if I saw the same group of men chewing the fat at a local hardware store I wouldn’t have approached them the same way (or at all) as I did on the radio.

If approached humbly these same people will try to help anybody who wants to become one of them do just that.  For example they want armchair copy, so to be one of them you have to run an amp.  Think about it they are older and can’t hear as well, in the hardware store they would be saying “speak up!”  They run horizontal antennas because they are all close together so NVIS is the mode of operation, vertical antennas just don’t work for this.

I could go on with why these clashes occur but now that I’ve been a ham longer I can ‘visit’ these groups without offense but I am careful about what I say and I am no longer offended that I don’t really fit in, it’s okay.  I understand now that their use of radio is just as valid as my own radio pursuits and if I let them bother me, it’s my problem.

I’m back on the air…

Posted in 73, EMI, operating, Radio on 2012/01/09 by NY4JB

I took almost a year off to do some other things but now I got the radio bug again.  It was surprisingly easy to untangle the ends of my two loops and get them back to the hamshack window and they both worked well right away.  Interestingly when I looked at the big loop the back end of it had been taken down by a couple of fallen trees.  One snapped the wire and left one end up about 30 feet in a tree and the other tree was holding the wire on the ground.  I got the one off the ground and secured it about 8 feet up in a tree temporarily and now I can’t tune up on 160 meters.  I’ll fix the loop in a few days and see if that helps but in the meantime it works just fine on 80 and up.

I still have some intermittent S9 power line buzz that usually starts when rare dx is on the air or right after a contest starts and stops an hour before the utility truck comes to check it out.  I tracked it to the offending poll in 2010 but never got it fixed.

WAS pursuit – in 2010 I worked all fifty states on 40 and 80 meters but never managed to get AR and KY on 20 meters (although I worked KY a few nights ago) and lacked about 10 on 160.  I already had WAS on 20 meters from several years back but I can not find the paper log with the AR and KY contacts.

I’ve been enjoying the OMISS nets, the YL System and some DX and am looking forward to the NAQP and YL QSO party contests although I wish they weren’t on the same weekend.

LOTW – I am not going to post to LOTW anymore.  Basically everytime I change computers it’s a royal hassle to get them to accept my uploads and then what’s the point of it, with eQSL it’s easy, all of the award certificates are free and it more closely resembles a real QSL card.  For example, if you are /m or /p and not logging you rely on getting a card from the station that is logging and then return one, with LOTW you don’t get a card you only get a confirmation if both stations upload a matching QSO.  Also, there’s no way to say PSE QSL on LOTW like with a paper card or even easier on eQSL since all they have to do is click confirmed.  QRZ’s logbook is OK but they don’t do anything to sort out dupes so if both parties upload their logs you get double entries but at least they are easy to deal with.

73 DE NY4JB

Antennas

Posted in operating, Radio with tags , , , , on 2010/10/08 by NY4JB

I’ve been doing a bit of research as I plan to add a third antenna to my farm and have noticed that most published designs spend all their effort trying to get a good match (low SWR) rather than getting the antenna to be effective.  Of course you need a low SWR in order for the antenna to accept power (and to deliver a strong receive signal) but that is easily achieved using a transmatch.  The catch is not to use coax after the transmatch since the high SWR will cause high losses on the coax (why do they even have coax outputs on transmatches?).  This means either feeding the antenna directly, with ladder line or using a remote transmatch at the antenna feed point.  BTW I have a pair of high end MFJ transmatches that are quite nice but they’re a little expensive.  I also bought a homebrew transmatch that is well made for much less and it works quite well but I’ve realized since then that a good low loss transmatch can be built for very little money if you don’t care what it looks like (or you can add a nice cabinet and it will still be cheap).

My current antenna collection consists of two loops.  The first is fairly large (about 400 feet of wire) forming a horizontal circle and fed directly at the shack window.  Little effort was made to get it to be high, level or have a great shape but it works well on the low bands (160-40).  The second is a vertical loop, again fed directly at the shack window, with a peak at about 55 feet, the low end around 10 feet off the ground and about 250 feet of wire total.  Again, no effort in trying to make it resonant or any particular shape/height and it works well on 80 – 20.

So what antenna am I going to add?  Most likely another loop since the receive noise is much less on loops than dipoles/verticals.  Although I must admit the ease of putting up a random length dipole is appealing since with loops you end up having to thread the wire back around to where you started and I could throw up a dipole it minutes…

Since half the fun is trying different configurations I may have to stick up a dipole temporarily on some military surplus fiberglass masts and see how it does.  One thing I know for sure is whatever I put up won’t be fed with coax.

73 & God bless,

-jim