Amateur Radio - W6CQZ

I would like to invite all users, new and old, of JT modes on HF to visit http://jt65.w6cqz.org where you will find a number of great people to help with your enjoyment of the mode. Also keep in mind, http://www.chris.org/cgi-bin/jt65talk which is the primary place for JT65 HF users to meet and learn from one another.

73 - Joe - W6CQZ

With the introduction of WSPR QSO mode the question has been asked, where should I operate WSPR QSO? My initial response was (and is) that WSPR QSO should operate near the normal JT65 QSO frequencies. With that being said I feel the need to give a clearer answer in that I don’t suggest that WSPR should operate on the same dial frequency as JT65 normally uses. On 20M the intermixing of WSPR and JT65A signals often leads to interference to both user groups though, in my experience, it’s worse for those running JT65A when WSPR is close than the other way around. So… I would like to suggest that WSPR operate at the normal JT65 HF dial frequencies +500Hz. By running at 14.076.500 WSPR can be close enough to JT65 ops that it may be seen by both user groups. Again, it’s only my personal opinion re WSPR dial frequencies.? It is up to each of us do one’s best to share the spectrum so I will leave it at that.

73 - Joe - W6CQZ

I note Dave’s comments ref lack of a help file for Terrestial JT65 operation. However, if you scroll down the help window you will see ” Examples of Minimal JT65 QSO’s” or press shift F5 to get to the same place.

The 1st example is clearly an EME QSO using OOO,RO,RRR.

The second example is clearly a Terrestial QSO showing reports in db etc.

If you do not see this help window then you have an older version on WSJT. Update now and RTFM not the Bozo Guide which I suspect has not taken into account the Terrestial modifications published by K1JT himself see below.

The full story of how to double right click and set calls and reports in ship shape terrestrial fashion is out lined in this URL. https://lists.berlios.de/pipermail/wsjt-svn/2007-May/000444.html

73 Gordon GW8ASA…GW3NDB

Hello Folks

As a user of WSJT since day one with over 3000 QSO’s under my belt. I would like to point out that since the incorporation of JT65 in another suite of programs, operating standards have gone to pot!

Please RTFM (read the free manual) it explains that TIMING is an important issue. Yesterday 15th July 08, I sat and watched Two stations one with a clock error of -1.8 secs trying to tell his partner, who had a clock error of 2.8 seconds that his timing was out. Of course the pair got nowhere fast.

I recently pointed out to one individual in Chris.org that he had a clock error of 9.8 seconds. About 30 mins later he wrote that “Radio Paris was showing he was within tolerance and that I should get a more stable machine”. I am sorry Guy’s this is just not the case. You must use an Accurate Time source. Windows time is not good enough. There are several ways of locking your machine to a standard time.

Download 1:- Dimension4. 2:-Tardis (both free). 3:- my favourite Socketwatch. 4:-Linux (has it’s own time Just activate the prog). Should you have no or limited internet access then GPS is the next way forward.

Enough on Time for now, lets look at two items I find very annoying in this adaption of K1JT’s software. There is a button which adds OOO to the end of each message line (what for) turn it off it means nothing in HF terms. Now the best one of all, there is a beacon button. What on earth is the point of calling CQ in each and every period your never going to hear a reply.

My penultimate gripe concerns Netting onto the station you wish to call. This is easy in K1JT’s software provided you have RTFM. I often RX in a Specjt BW of 50hz or less as do many experienced operators. You will simply not be seen (decoded) if you are wasting valuable space by calling 300hz high or low.

Lastly what is transmitted in K1JT’s sofware is shown clearly in the little box at the bottom right of the window. You may have typed in what you think is a report but if it doesn’t show here then it isn’t TX’d and your partner will never get his report, remember there is a 13 character limit to messages and they cant start with R or 7.
When You go into a DIY store/shop for an angle grinder are you the type that comes out with a Swiss army knife or the latest device with multi attachments to do every job in the book? No of course not, we all know you get what you pay for and attachments will never equal the correct tool for the job. So adopt that approach to JT65 get K1JT’s software but please RTFM before you screw up.

You want help then email is on QRZ.com I will try and help but please I am no computer man.

73 Gordon GW8ASA/GW3NDB

I have received many queries about the status of WSJT with Mac OS X of late. I wish I had better news to report, but the status is the same as when I posted on this subject some weeks back.

It is possible to compile and run WSJT on OS X but at this point it is neither easy to do or worth the effort if you are not doing so to work on the code. I have not had the time to go beyond that and I am not sure if I even have the skill to go beyond that. If you want to see WSJT working on Mac OS X then your best course of action is to generate enough interest such that those who actively develop WSJT see the need to expend some effort in that direction and, even more to the point, help find some programming talent to work on the project.

I am more than willing to pass on the knowledge I have scraped together to anyone who is working on WSJT OS X, but the work remaining is beyond my ability to continue. The explicit directions to compile a barely functional version is posted in the WSJT Developer’s email list at

http://lists.berlios.de/mailman/listinfo/wsjt-devel

If need be I can find the original posting I made and forward it along but it is not a trivial process and it does not yield a fully functional WSJT for OS X, it merely gives one a base to work from.

73 - Joe - W6CQZ

use my callsign at w6cqz.org for email.

I have been playing with rolling my own receiver.. here is what I have so far.

The board clamped to the desk is a 14.085 MHz VXO feeding into the box in the background which contains the LO splitter (for I Q pair) and in phase RF splitter which feed into the pair of SBL-1 mixers. The amazing (to me) thing is that it actually works as is with no RX pre-amp or filtering and no post mixer amplification. It may not work well but it works.

Now on to the pre-selector and RX pre-amp plus some post mixer amplification and low pass filtering.

I am pleased to report that WSJT can be compiled and made to operate on Mac OS X. It is not a trivial process to make WSJT work on Mac OS X, but it will work! As of today, 17-December-2007 I have been able to have WSJT receive and transmit JT65A on my Power PC Based Mac and see no reason why it would not work on Intel based machines as well.

BUT.

When I say it is not a trivial process to compile I really mean it. For what it is worth, I have now seen that WSJT will compile and run properly under OS X, but I am still a long long way from being able to package the software and provide a download for others. I intend to post my findings to the WSJT developer’s mail list and, perhaps others will help me work out the remaining issues and someday there will be an OS X release. Until then I hope those of you waiting for WSJT OS X will at least know it is not an impossible thing to have.

73 - Joe - W6CQZ

Please note that you register for the JT65A chat/Reverse Beacon system at jt65.w6cqz.org not here at the blog.

73 - Joe - W6CQZ

Thanks to Joe Taylor - K1JT we have two new modes to experiment with in WSJT 5.9.8_r558.

For a full description of the new modes see;

http://physics.princeton.edu/pulsar/K1JT/JT2_JT4.TXT

To download the new release see;

http://physics.princeton.edu/pulsar/K1JT/WSJT598.EXE

Please take the time to read JT2_JT4.TXT as it contains some very useful information.

Beyond that I will talk a little about what I have learned about the new modes over the past weeks.

Do not overdrive your transmitter! JT2/4 use PSK modulation + FSK sync pulses. If you overdrive your transmitter you will create splatter similar to that of an overdriven BPSK31 modulated signal. JT2/4 is not quite as prone to creating splatter as BPSK31, but it is not like the simple single tone at one time modulation of JT65 where you could push your transmitter into its non-linear region without dire consequences.

Do not overdrive WSJT! If you are seeing problems with decoding (especially it seems) JT2 transmissions then look to the RX noise box in the main WSJT window or the lower right hand box in SpecJT and be sure that you are not seeing levels above 0. With my setup I find that it is better to be in the -2 to -3 range with no signal present and have found it necessary to decrease RF gain and/or engage attenuation on very strong signals.

Different sound cards can give very different results. This also applies to JT65 modes, but seems more pronounced with JT2. I run WSJT on both Windows and Linux and in both cases have seen different results with different sound hardware. This is not a guess, it has been observed by running two instances of WSJT on the same computer using two sound devices fed by an audio stream split between them. I observed one sound device would only decode about 75% of what the other could decode using JT2. With JT4 it was more like 85% and with JT65A around 95%. Audio levels were adjusted to be the same into both devices and I paid close attention to WSJT showing the same Rx noise levels for both instances. Also sampling accuracy was monitored and both cards display 1.0001 for input and output sampling factors. Further investigation of this seems warranted, but the immediate conclusion is if you have more than one sound device available it might be worth trying all your devices to see if you find one that works better. For what it’s worth (very little actually, as my good luck may simply be good luck), my best results come from a Soundblaster 16 PCI that I picked up at a junk sale for $1. It is also worth noting that I have seen comments from another user saying he found that changing from one piece of sound hardware to another made noticeable improvement to JT2 decoding.

Another point you should be aware of is what all the submodes of JT4 do. Simply put, each increment in submode of JT4 increases the occupied bandwidth of the generated signal. JT4G is a bit over 1200 Hz occupied bandwidth. Refer to the JT2_JT4.TXT file for the full details.

Reverse Beacons and the new modes…

Since JT2/JT4 use the exact same message formats as JT65 the RB system works fine with WSJT in either of the new modes. The only point of confusion will be what mode a specific RB is in. At this point there is no way to indicate mode of an RB other than to announce it in the jt65.w6cqz.org chat logger. That may change in the future, but for now you will have to either try 65A, 2 or 4A and see which mode a particular RB decodes (assuming it hears you well enough to begin with) or log in and ask the RB operator. AUTO-0/W6CQZ will be in either JT2 or JT4A modes at all times it is active. AUTO-1/W6CQZ will be in JT65A. Those two RBs operate in parallel from the same radio. AUTO-2/W6CQZ will be in JT2 on 30M with a switch to 4A or 65A if I am present and see the need to change mode.

73 - Joe - W6CQZ

As I have expanded the number of RB Stations it is becoming somewhat more difficult to add a welcome for each station, but I am thankful for each and every new station who decides to participate.

We all owe our thanks to the following new stations.

WD4KPD - David - FM15mm

K7EK - Gary - CN87tb

VE3CDW/W7 - Barry - DM26ic

IK1RKU - Ettore - JN45ik

73 - Joe - W6CQZ