I made the jump into digital Friday when my Signalink USB arrived. The instructions said to set the radio power output to max and set the knob on the Signalink to about half. Does that mean I now use the tx knob to adjust output power for the transmitter? Or do I need to change the setting in the radio itself so I don't wipeout everybodys waterfall.

  By the way, my first digital qso was Bigdaddy004. I believe he was greatly impressed by my ability to retransmit the same thing over and over before I figured out how to erase the text box.

This. The Tx knob on the SL is where you adjust your output power.

Have fun. Digital is addictive.

When you say radio output power to max, you don't mean 100w do you?

All my psk contacts have been 30w or less.

LOL, you did very well for your first digital QSO!  Thank God I had a patient operator on my first one because I really screwed things up!  


Yep, that's how I do it, also, when using an external soundcard interface like the SignaLink USB.

Radio power was set at 100 watts. I had the TX knob between the 10 and 11 o'clock position on the Signalink. Bigdaddy said I had good strong signal but didn't say if I was wiping out the waterfall on his end.

I guess with an external audio adjuster you could do it like that. Do you have an external power meter? With my donner I set my computer's volume so that my ALC is minimum and output power is same as my power setting.

I use a Daiwa dual needle meter.  I was so excited I made the thing work I didn't think about checking power output. I will definitely check that next time.

Hrd IS bloatware.

wHILE i USE IT, THERE'S SO MUCH STUFF ON IT i PLAY HELL TRYING TO FINGER IT OUT

cAPS LOCK SUCKS

I really want to get into digital and have been looking at the Signalinks.   Tonight, in fact.    How hard is it to get up and running?    I'm not a computer guy and I'm really worried that its going to be more confusing than fun.  

What kind of radio do you have OP?

It does have a learning curve, but is quite robust. Can do the majority of digital modes.

It's kind of the glock vs 1911 argument. Either you like HRD, or you hate it.

You weren't wiping out the waterfall at all from my perspective.  Next time we have a QSO, I'll take a screenshot of it.

You can also set the radio's built-in meter to show Power Output (Po).  Use your SignaLink TX knob and watch the Po meter and set it where you want it.  I do that with my IC-703+.

Fldigi is for 1911 lovers
Hrd is for glock fan boys

I like Glocks and HRD/DM780.  YMMV.  

I hate glocks, but love 1911s.

HRD has more bells and whistles, just like the 1911.

fldigi, digipan, etc. are all pretty narrow...just like glocks. They work, but lack a lot of the added features,

I am a 1911 guy and see it a little different. Fldigi is your base 1911, but you can add better parts like flarq, flmsg, flrig if you wish.

Oh and its open source.

10 Tips for the PSK31 Digital Mode

Check the ARRL site above for some useful tips.

Open source? Like the 9 million different manufacturers of the 1911? Many people make glock-ish knock offs, but all of the 1911s have very similar basics, mostly interchangeable parts, etc.

lol...thread derailed.

I have used both FLDIGI and DM-780.

Each has its pros and cons. For Emcomm and Linux, FLDIGI reigns supreme.

The free version of HRD is sometime a bit buggy. As times goes on,  the only way to use HRD will be to pay for it. The version 5.0.24.38 logging software is no longer being updated for DXCC and if you are wanting to track your contacts for DXCC that may be problematic. I also experience random crashes with the logging program and DM-780.  The new version of HRD is 30 day trialware, so if you like it you will have to register it for about $99.00

FLDGI is freeware and is still routinely updated and fully supported by its author.

Hsracer: The instructions were pretty detailed on the set up. Not much computer skills required at all. It has pictures to, that helps me more than anthing it seems. Radio is a Yaesu 857d.

GCW: I own a 1911 and Springfied XD both, not sure where that leaves me.

Piccalo: Looking forward to the drill next Friday. Only one radio to share between phone and digital modes, I now have to explain to the wife why I neeed another radio.

'Tis better to ask forgiveness than permission.    (do it, Do it, DO IT !!!)  

Interesting. Just checked out the HRD page. Wasn't aware it was sold, and is now a commercial entity. $100...wow... swift kick in the nuts. Maybe I will be going elsewhere when it's time to upgrade.

But the OP question... yes, you set the transceiver to 100 w and Upper Side Band.

The actual power output depends on the audio drive to the radio.  So, for your Signalink you adjust the knob.  You can also adjust the TX audio slider in the radio pane in HRD.  It is on the left side of the DM780 screen.

While transmitting your CQ macro, looking at the power meter (and best to have an external meter that has reasonable accuracy) adjust your power output to no more than 25 watts.  18-20 watts would be just as good and you will have almost no possibility of any splatter or distortion, or "wiping out the band".

Adjust the RX slider in the radio pane to give good contrast of digital signals to the background.  Too high RX audio level and it all looks the same, can't tell what is what.  Too low and the signals look faint, hard to see.  You can tell quickly what is right for that.

So, why do it like this, setting the radio to maximum power output and adjusting the audio drive?  Why not just set the radio to 20 watts?  Because, a SSB signal output will be proportional to the input.  If you have the power setting to 20 watts, and you have the audio drive too high, the signal will flat top and distort and splatter.  If you have the radio set to max, 100 watts, and turn down the audio, the signal will be very clean.  You will have lots of "headroom" to adjust up or down.  Switch the radio meter to ALC.  If you see ANY ALC showing at all, your TX audio drive is too high.  Back it off.  No Compression, either.

Also, for receive, NO NR, NB, ANF.  No DSP of any sort.  None of this.  It will distort the signal and increase error rate.

One thing that hung me up when I started... if using a digital/packet port ( i.e 857, 897, etc) make sure your radio is set to that mode, and the mode is set to USB.

niether HRD nor FLDIGI is 1911


1911 is CW  

Thanks for this. Somehow I missed this when setting up HRD and my signalink with HRD. I always turned the power down to about 20W and then adjusted the TX on the signalink to about 11:00. Never had a complaint, but have only had a few QSO's.

But like that, you have a very narrow window of adjustment of your audio drive.  It is very easy to overdo the audio and distort.

You can use as much power as you like, but keep the TX drive low or you will make a mess out of the frequency by having harmonics and all sorts of nastiness!

The real key in Digital modes is to have ZERO ALC Voltage.

a Clean 5 watt signal is Far better than a crappy  100w signal

Dammit! I just shut down the radio and now you guys have me firing it back up so I can twiddle with the settings again.

oh well, I wasn't going to do anything between midnight and 6am but sleep anyway.

Radio to max power, that is 100 w USB.

Turn the knob on the Signalink all the way down.  Or if a Donner Digital Interface, there is an internal adjustment pot, turn that down fully counterclockwise.

Set the TX Audio slider in the radio pane of DM780 to 50%.  This will give you room to go either way, to increase or decrease power, and is an easy visual reference to remember.

Start a CQ macro going.

Now turn the TX audio knob on the Signalink up (or the adjustment pot inside the Donner interface) until you reach 20-25 watts.  Check the radio again that NO ALC, I repeat NO ALC showing.

Now leave the knob alone, and perhaps mark the position.  On the Donner you can put the cover back on the box.  

From here on out you will adjust power with the TX audio slider in the radio pane of DM780.

If you use FLDigi, you will use the FLDigi slider in Windows sound mixer (right click the speaker icon in the sys tray to get there).

Now be prepared for the compliments on your clean digital signal.

It is great to see that people are finally getting the concept of amplifier headroom!

For a slightly deeper dive on this, it is necessary to understand the concept of peak-to-average-power Ratio (PAPR), also known as crest factor.

When running sound card digital modes you will find that many of these modes are comprised of multiple, simultaneous tones in the passband. All of these tones are going sum to a total, instantaneous drive voltage at any given point in time. This summed signal will have some average level and this is what most of us normally see because most of us have average reading RF power meters. But there will also be many peaks and valleys. The peaks are important, but without a method for reading peak power you don't necessarily know what it is.

For some modes the crest factor is well known. For example PSK31 has a crest factor of 3dB. So for the typical 100W HF radio, do not turn up power (using the audio drive level--the rig is set to max!) above 50W indicated on your average reading power meter. At 50W average the 3dB crest factor equals 100W peaks. (For those of you who don't understand Decibels, suffice to say that every 3dB equals a doubling or a halving, i.e. +3dB means multiply by 2, +6dB means multiply by 4, +9dB means multiply by 8. If it's -3dB divide by 2, and so on.)

Again, most of us do not have a method to read peak power, neither an expensive peak reading power meter nor a cheap oscilloscope type station monitor. So we are forced to use non-direct means of determining what a good power level is. One way is to use a theoretical calculation, as I did above. Another is to use ALC meter indications. Unfortunately most ALC indications are quite imprecise. Icom radios are notoriously conservative where ALC indications are concerned. Probably the best test is to simply ask how your signal looks to others on the waterfall and to see how well people receive your signal in general.

All of these same issues occur when running phone (voice). So why does it matter so much more on digital modulations? There are at least three good reasons. Probably the most important reason is that digital modes tend to be narrow band and cluster together in tight little sub-bands. When there are 30 narrow PSK signals packed into a 3KHz sub-band and one of them is crapping all over 1KHz of that with intermodulation products it's going to be a) glaringly evident to everyone and b) piss a lot of people off. Interference on digital sub-bands is just a lot more noticeable and deleterious to other signals than something similar on phone. A second reason is that digital modulations need to remain undistorted to a much greater degree than voice signals. That Mark 1 neural net computer in your head can deal with a lot of voice distortion and still demodulate voice just fine. But the same cannot be said of the software modem in your favorite digital mode program on your PC. A third reason is that digital modulations tend to be high duty cycle. So your amplifier is always slammed to maximum power and this places a lot of stress on both the final RF amplifier transistors specifically and the rest of the rig in general from heat build up.

All that said, it has been my personal experience that a certain amount of distortion is still a good trade-off for getting your signal through in tough conditions, much the same as turning up compression on your microphone audio for phone. I regularly run a few bars of ALC on my Icom 7000 to no ill effect, and those of you who I have had digital QSOs with know that my signals always look good in the passband and decode at 100% print, both of which together are the acid test of drive level. The only place I've found this not to be true is for modes with a large number of carriers, e.g. MT63-1K, which has 32 carriers. For more common modes, like Olivia, Contestia and PSK, you can get away with what seems like murder most of the time.

I'd be willing to bet that most of the very crappy looking signals are guys running with their rigs set at 20W and driving the hell out of them with too high audio levels. That is going to look a lot worse from a distortion perspective than someone with their rig set at 100W and driving it conservatively at 50W average.

Thanks aa777888-2 I will now change my operating practice. I have gotten pretty quick at alsamixer haha.

But with all that you didn't say which software suite was the 1911..

Editing because I wrote a bunch of stuff that I just now saw that aa777888-2 wrote much more eloquently than I did.  

What an excellent post aa777888-2!!!   Perfect!!!

outstanding post.  OP,  this.

Well, I run HRD for radio control but have interfaced Fldigi to HRD and do NOT run DM780, which I find incredibly bloated. So what the heck do I know?

Normally, I set power to whatever level I want (for dig usually 30w or so. Then, I adjust the volume/modulation so it's just tapping the upper edge. May not be the textbook correct answer, but has worked well.

Thanks Jupiter7200  and aa777888-2 for the simple setup instructions and the reasons why it's done that way. And to the guys who mentioned fldigi, I'm going give it a try too.


I didn't think one small question would result in two pages. I've still have over 9 million questions to ask but I'll try to spread them out over time. Hope this topic has helped a few newbs like me and future amateurs as well.

I was a long time HRD / DM780 user.  I really liked DM780, though the more bloated HRD got, the more it sucked.  The last free version had some problems, possibly on purpose to get you to buy the Paid For official version.  I had been looking for a change.

Friends all suggested either Digipan or FLDigi as alternatives to HRD/DM780.  I had tried Digipan 5 or 6 years ago, and it was a "lean, mean, fighting machine", perhaps a little too simplistic, but I like that.  The problem is it is no longer supported, has not been for some time now.  So that left FLDigi.

About this time my club and other EMCOMM groups along the coast have been setting up, experimenting, testing (1) portable setup, (2) NVIS antennas, (3) digital.  At a regional hamfest some of the other club members saw a presentation of uses of FLDigi and some add-on programs and came away very impressed.  Since they had not been previous users of digital, had no time and effort invested in any other programs, it was decided that we, as a club, for club EMCOMM and networking with other clubs and EMCOMM groups would also use FLDigi in order to also be able to use the valuable add-ons.

(1) Portable setup.  There are as many ways to do this as hams participating, and all are good.  I like to see what others do like this, something to learn from each.  Simple workhorse radios seem to be top choice, such as Icom IC-718s, but the IC-7000, Yaesu FT-897D and FT-857D are also popular.  Other accessories, often the LDG IT-100 for its simplicity and good performance is the tuner of choice for the Icoms, and comparable LDG tuners for the Yaesus (YT-100, AT-897).

Aside - Though my club has two IC-7200s in the club station, I have not seen any IC-7200s used outdoors yet.  I would think the overall performance, O-ring seals and water resistance, and ruggedness of the IC-7200 would be advantageous for portable use.  Realistically, most guys use older rigs, rigs they are well practiced in using and confident in, mostly ones that they have taken out of service at their QTH and replaced with newer, better, more expensive radios.  The IC-7200, being a relatively new radio, does not fit this pattern quite yet, but I'm sure it will soon.

(2) NVIS antennas.  Simple 1 band dipoles to OCFDs, mounted low, from 8' to 15', a few guys with verticals, but those are not performing as well as low horizontal antennas.  And for close in, true NVIS, a radius of say, 200-300 miles, 40 meters seems to be the place to be.  20 and 15 meters for DX.

(3) Digital.  FLDigi with its add-ons, FLMsg and FLamp are the top choice.  Also we are experimenting with modes other than just PSK31 to send forms and files at higher rates.  

FLMsg is an add-on that has built into it the standard Radiogram, ICS, Red Cross health & welfare, and other such forms.  You type in the blanks, transmit the form via FLDigi, and your contact can receive the file and print out the form on the other side.

FLamp allows drag and drop transmission of txt, Excell, and other files.  The shorter the better.  For example, a plain text file will be much smaller, and therefore transmit faster than a MS Word, PDF, or other large file, yet transfer the same information.

Due to all of the above I have abandoned HRD and have switched over to FLDigi.  I'm learning the ins and outs of that now.

Jupiter7200

Look up danny's digital packet. Just another reason fldigi and open source are great.