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Handling Packet-Pileups
Home > HF Contesting > Tips and Techniques > Handling Packet-Pileups
This page discusses ways to handle packet-pileups.
The 'Packet Pileup' phenomenon, when a DX station is suddenly called by lots of other Hams in a contest after his callsign has been posted as a rare 'spot' on the DX packet network, is growing problem, and one that DX stations need to learn how to deal with. The following is a posting from the CQ Contest reflector that discusses the problem and ways to approach it.
 

From Martin, VK5GN

I have generally viewed packet spotting as an interesting piece of technology. Un-useable here in Vk but generally benign as long as it is kept to its own class. It is NOT single operator.

However, after this weekend I am increasingly of the view that it is a danger to contesting. Or at least it is in the way it is presently being used.

Let me illustrate first by some experiences this weekend. I was cq'ing on 40. I obviously got spotted on packet because it went from 4or5 in the que. to something which resembled the pile up for a dxpedition to a new island! Now on phone that just makes me rub my hands with glee as I see how fast I can clear it and get down to zero callers. Although I have previously noticed it slows the rate. On CW my skills are less good. At best my operating skills on CW could be called average. Controlling the mess is a real challenge.

I observed what was happening and there were calls joining all the time they demonstrated the following "crimes",

* Many did not check to ensure they knew what the vk5gn signal sounded like. They would stomp in while I was extracting a call. * Many were calling on a second radio. And when I went back with a partial call they were not ready or not paying attention. I won't embarrass anyone but these are big players in contests and ARE on this reflector.

* The signals seem to spread out slightly. This makes beating between signals much worse than in a "normal" pile. I don't know if that is my imagination or there is something in getting automatic spots that makes everyone slightly apart. But not far apart enough to let me sort them out with RIT.

* Some strong signals were not listening. Could have been the two radio thing OR they had RIT on and while the TX landed in the right place on computer command the RX did not.

The effect is different on different folks:-
First - our newbie contester. He has been S&P ing for a couple of contests and thinks he would like to try a run. He gets on calls CQ and quickly makes a few QSO's. Boy is this fun he thinks. Then suddenly he lets go TX and this howling pack decends on him! He is not experienced enough to control it. Anyway he is probably a long way from the centres of this stuff in US and europe and probably running a lot less power so he cannot put a commanding signal on the frequency. What is he to do? And what effect will it have on his interest in developing contest skills.

Second - our keen contester just on this one to give out the mult, (what I was doing this weekend.) The effect is irritating! The 40 pile mentioned above I left and QSYed to 80 when I sent k4u?15 times. I should have got a station whose call had a k4 and a u (I think it ended in u never did work him) What I got was bedlam. I figured that if after 15 times I did not get either the k4 or a clear frequency. By clear I mean no one calling me. Then it was never going to get under control. I didn't go back to forty while it was open to stateside.

Third - the keen contester trying to make a score. I've wondered what to do and I think the answer is the same. Move. I did try something on 10 Monday morning my time. The packet racket hit me and the rate decreased gradually from 180 to 90. I needed a potty break so figured I had nothing to lose. I came back to almost the same frequency only two minutes later. The rate climbed back to 150 within 10 minutes., sure I had to cq a coupla times but the rate was better and when I am cqing rate is what it is all about! The moral for me on CW is leave the big piles and move. That is going to leave mess and QRM on the band if a lot of us do that.

I don't see any of this being good for contesting or ham radio in general. In fact I think that some of the poor techniques demonstrated in pile ups have developed as a result of nets, packet etc. in general dxing. There needs to be a discussion of what are appropriate techniques for joining a packet pile. It really is making contesting in "semi rare" places less fun than it used to be!

From Pete, W0RTT

Dear Martin,
I totally sympathize with your predicament. Packet has definitely become a situation that DX stations must learn how to deal with. This is what I recommend:

First, consider a pileup as the concentration of information overload. The goal is to spread this information into reasonable bits by breaking it down to accurately select a only one caller at at time. Unfortunately, the pileup is behavior oriented. Managing it with logic doesn't always work. It's mood is tied to human nature: Eager beavers. Panic callers don't have the patience to use all the right procedures.

It is the control station (DX operator in this instance) who must take charge.
a.. On phone, you can attempt to scold behavior and hope for understanding. You will fail because your callers will become even more unruly trying to identify the bad guys and making additional QRM in the process.
b.. On CW, the yelling and screaming is only heard within the frustrated caller's shack. He will try to out-gun his counterpart with his power at any cost.
Today's transceiver's typically have dual VFO capability. With this feature, I recommend the following because it has worked for me every time, and that is to use two transmitting as well as receiving frequencies. Here's how it works:

  1. Find a decent clear frequency to CQ with and begin the process. As the pileup builds, work the edges of the pileup only. Callers will gradually stop calling on your frequency because they will find the previous successful guy's frequency and zero beat him because that is where you are listening.
  2. As the pileup builds your QSO rate will tend slow because of the listening problems on both sides of the path. If you have the capability, increase your sending speed to weed out the slow callers. The disadvantage to this is that you might miss a juicy multiplier that simply cannot hang around.
  3. Finally, just stop and let them continue to call. While they are doing this, look for another clear frequency and begin another pileup. By the time the callers on the old frequency die down to a manageable count, your new frequency will likely have built up another saturation level. Then, with your trusty VFO switching capability, go back to your original pileup and start picking the straglers off. Toggle back and forth from one pileup to the other and you will be amazed at how quickly your rate will return to normal.
  4. If you do not have a dual VFO transmitting capability, then you can jot down the original pileup frequency and manually set the transmitter back and forth from one pileup to the other. It may require a bit more playing with the knobs, but in the end it will be more efficient.

The Pacific is particularly prone to difficult pileup management issues because of such long distances between population centers. When I was on Johnston Island 10 years ago during a fantastic solar maximum, conditions to Europe were exceptional. However, the signals were typically in the 3 to 5 S-unit range. A pileup would simply sound like a lot of noise and undistinguishable if narrowed to just 1 or 2 KHz. To further exascerbate the problem, all Pacific stations are considered to be juicy multipliers, especially during the tail end of a contest.

I learned that split operation by a DX station rarely works during a contest, but is the preferred approach for DX operation outside of a contest.

Incidently, I played this weekend for the first time in a DX contest since the "Great Colorado Shootout" of 1997 CQWWCW. I was on 20M sharing with W1XE operating from Multi-multi station, K0RF. Chuck has a great station, great QTH, and outstanding hospitality! With Chuck's permission, our team is hoping to post some PIX of this operation for those interested. It was a fun weekend for me! I hope you gained some fun from this also.

 
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