Discussion in 'Straight Keys - CW Enthusiasts' started by NG9F, Oct 17, 2018.
It depends on the band. What frequencies do you operate on?
80, 40, 30, and 20M
Firstly you need to be wearing headphones (cans).
Low bands: Turn off the RF preamp stage if your receiver has one. Narrow up the passband and tune to the side of zero beat that has less QRM. You can employ some outboard doo dads: National Select-O-Ject, and Autek QF-1A for example. But get just enough signal to copy above the noise level.
It all starts with antennas. Receiving antennas for the low bands provide a better S:N ratio. There's a whole book on that: Low Band DXing by ON4UN. Get it and read about receiving antennas. On 20 meters (and maybe 30) if you don't have a beam and want to improve your reception, try a two element yagi at around 30 feet and see what that does for you.
Noise from local RFI is an entirely different matter and a whole topic unto itself but the first thing is to attack the S:N ratio problem, whatever the noise may be. It can be band noise, QRN, QRM or RFI. Then gadgets and receivers follow.
Good fitting headphones are a MUST.
Best ones fit to cover the ears so no sounds are heard other than the radio.
You will be amazed at the difference they make when copying weak signals and in poor condx.
Learning how to manipulate the various rx i.f. width, shift with its' passband and rf gain/attenuation will help too.
It's no big deal to miss out on part of the conversation as long as you are getting the most of it but ask for a repeat of questions, hi.
My headset is like that. It also has a phase reversal switch that sometimes makes a difference.
I tend to keep things simple.
I usually run 500 Hz filters on CW, and the only controls I'll touch mid QSO are the attenuator or the volume knob. If those don't cut it, well, I'm in for a short QSO.
I run a QRP Labs QCX or a Kenwood TS-930. The only knob I miss when on the QCX is the ability to change bands.
Posts like this are very interesting to me. I've only had 70 QSOs with CW now, but at this point if I had to pick only one control to use it would be RIT. Sometimes when I roll it back and forth a signal that is gone just pops right back up so the QSO can continue. Or that's how it seems. I'm running a 7610.
I've been thinking more about this and have some questions:
1. How long is the radio on before you get into QSO?
2. Does using RIT do the same thing when listening to some other operators in a long QSO?
3. How tight of filters are you running?
My suspicion is that your transceiver may be drifting in frequency. Somewhere in that radio is a crystal based oscillator. None are perfect, and drift is really common in many crystal oscillator designs until they stabilize in temperature. An easy way to check is to leave the radio on over night and see if RIT is as useful in improving reception.
I also wonder if the really tight filters in modern radios are so tight that any drift (on either side of the QSO) pushes a signal out of the filter passband.
Then again, I might be barking up the wrong tree.
I don't think that's it because when I am on sideband I never need to adjust the RIT, and the voice never gets weird. Also I can be in a CW QSO for 20-30 minutes where the other station is 599, and it stays perfect. It's just when I am working a really weak signal that RIT seems to help. It is almost like the ionosphere is "filtering" little bits of the signal, and a slightly varied frequency gives me a part of it that is making it through. Or that is my guess- I don't really know why it seems to work. It worked great last night with a station in Connecticut- he gave me a 479, and I gave him a 359. It was tough to dig out, but we did a whole QSO with a little bit of help from the RIT. I never had to go far- I don't know how the RIT is set on the 7610, but it seems that I could go less than -0.10, and less than +0.10, and I could always "find" him again in there.
I have added an MFJ 784B Tunable DSP Filter between my Ten Tec Omni 6+ transceiver and the speaker. It is amazing how the 784 can pull signals out of the mud. And if your receiver lacks selectivity and nearby strong signals overwhelm the signal you want, the 784 notch filter function will save the day. I think a tunable filter like this one can improve many older rigs.