About CW filters

My first two CW contacts as activator were 7 years ago from EA8/LP-002 at 8 WPM. It was scary but when I hiked back to the car I felt high as a kite (no drugs needed here, hehheh). I wasn’t very well trained yet, and relied on the decoder of my KX2 as well.
But, you’re 18WPM, that is a good speed compared to where I started. Don’t worry, just do it. Throw out your call and use ???'s for repeat. No kittens will be hurt if you ask for repeats.

73, Martin

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Hi Remy

When first licensed (1976) I had a Yaesu FT-200 HF radio. This had no provision for fitting a CW filter in the IF, the SSB filter was the sole option.

As a committed CW OP, I bought a small low-cost audio filter that used a few (741?) opamps. As I recall this offered bandwidths of 100, 150 and 200Hz centred around 700Hz. I think it was made by MFJ.

I also homebrewed a switchable resistive attenuator to go in the RX antenna feed from the rig’s antenna changeover relay. This kept strong signals at bay.

Youthful good hearing, enthusiasm, and adrenalin were all on my side.

Over some 2-3 years, I had a massive number of CW QSOs, mainly throughout long dark nights on the LF bands, while my parents slept soundly in the next bedroom, knowing absolutely nothing … a story that is probably familiar to many :slight_smile:

These days, legacy AF filters regularly pop up on the second-hand market. Indeed, I continue to use my 40-year old Datong FL2 with the TS-830S to ‘polish things up’.

73
Dave GM4EVS

PS No paddles or bugs, just brass-pounding :open_mouth:

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I keep a sheet of scratch paper handy, and use that more than the log sheet when I’m operating. Many operators are running faster than I can reliably copy. so it may take a few tries to confirm their complete callsign. (The “B6B” in my callsign seems to cause similar uncertainty.) I also write down their exchange information while they are working other stations if I have a chance. Then, when (or if) they respond to me, I don’t get flustered and forget to write it down. This works better as a chaser than on a summit running stations, of course.

If they are chasing you, then transmit at a comfortable speed and keep asking for repeats if they are sending too fast. They may eventually learn that sending slower takes less time to work you.

There are standard methods that contesters / DXers use to handle pile-ups. If nothing else, try to pick out a letter or two from a callsign, often the ones that drag on after the others have finished. Then send, “U?” or whatever letter or partial call you heard, to reduce the number of stations at a time. Sometimes you might pick a letter at random, even if you couldn’t copy anything from the bedlam. Or even a hopeful prefix: “VK?”.

With a home rig, you should have plenty of volume in the headphones to add a passive low pass (or bandpass) filter. I found with the audio filter in my Ten-Tec Arogsy that I left the first stage in most of the time, even when listening to SSB, as it removed a lot of annoying noise. Switching in the second stage provided good results on CW, and even improved the performance of the narrow crystal filter. I’m in the process of building them for my other radios.

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Most of all, don’t send faster than you’re able to copy, this gives an indication to chasers at which speed you’re comfortable with, otherwise they can’t possibly know, even if they’ll eventually understand after many AGN?

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…and allow for the fact that a cold wet windy summit is likely rather less optimal for listening than a warm dry quiet shack, so it may be worth dialing your speed back a bit from what you’d use at home.

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Yes this is also adding to the list. I’m going for a triple 10 pointers activation this week at almost 3000m altitude. Maybe -5 to -10°C but full sun expected. Not the best scenario to begin with :cold_face:

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