Do I need a cw filter?

Discussion in 'QRP Corner' started by KE9RJM, Dec 22, 2017.

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  1. KB4MNG

    KB4MNG Ham Member QRZ Page

    I've never had a rig that has not had a filter. I'm not the best cw op but there are times there is no way you can communicate with out one. Not necessarily crowded conditions but more of someone parking real close by and wiping out who you are listening too. It also minimizes hash that makes the qso much more enjoyable.
     
  2. KB9BVN

    KB9BVN Ham Member QRZ Page

    I have always had rigs with good CW filtering....I'd probably die if I couldn't filter down to 150 Hz. I operate most of the time at 250 Hz
     
  3. NM7G

    NM7G Ham Member QRZ Page

    Let's not overlook the improvement in signal-to-noise ratio that comes with more selectivity, even if there are no interfering sigs close in. I do a lot of weak signal dxing, mostly successful. The 500Hz filter in my TS930S is in circuit 99+ percent of the time. When I ran Drake twins, the R4C had both 250 Hz and a 125 Hz filters.
     
  4. N1OOQ

    N1OOQ Ham Member QRZ Page

    Yup, a good 500 hz xtal filter really reduces the noise. I used to keep it on 95% of the time with the Tentec. I only ever needed the audio filter during contests.
     
    KC9UR likes this.
  5. W4ZNG

    W4ZNG Ham Member QRZ Page

    Nice to have for PSK-31 too. I've got a 300 Hz filter in my 817, and it's even a lot more handy to have than I initially hoped it would be. It's really working out great.
     
  6. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    I would let experience make the decision for yourself. If you are having difficulty hearing a station because of too many others operating close to your frequency on a regular basis...you may wish to invest in a filter.
    In my opinion...I haven't heard too many operators out there lately. If conditions change a filter is usually a simple upgrade.
     
  7. KB4MNG

    KB4MNG Ham Member QRZ Page

    Noise reduction is a huge benefit.
     
  8. K8JD

    K8JD Ham Member QRZ Page

    Filter Advice
    Y E S ! trying to operate ANY CW can benefit from having a narrow IF filter you can switch to when conditions require it.
    Another QSO can start up close to the freq u are using and wipe out the other station if you can't switch to the narrow filter.
    Even for Urban Noise, the narrow filter gets a signal thru the noise much better.
    Operating QRP on fone can be frustrating but on CW the QRP signals get thru much better .
    I work QRP stations quite often on CW and it's amazing how far they are getting out.

    When I bought my TS520 new, it came without the CW filter and when I hooked it up and operated for an hour, I got right on the phone and ordered the CW filter. Using the SSB filter on CW was TERRIBLE, the QRM was bad and on my old receiver with a 500 HZ filter I had no QRM when I switched antennas to the old rcvr.

    Audio filters and filtered speakers can not help when a strong signal in the wide IF bandpass starts pumping the AGC and you loose most of the volume on the signal you want to hear.
     
    Last edited: Feb 24, 2018
    KC9UR likes this.
  9. WM7WM

    WM7WM Premium Subscriber QRZ Page

    Do I need a filter? Um, yes. One that works. I installed the 500hz CW filter in my new FT-818nd and the bandwidth was still wide open. Sent it back and bought the 300hz filter. Um, still, wide open. I'm spoiled I guess with the variable, narrow, and steep walled filters on my KX3 because mechanical filters just aren't good. If I have a signal on say 7.023, I can still hear it down to 7.022 and up to 7.024. God forbid there is another operator even near those freqs. I bought a Collins filter that was not cheap. The specs say it's minus 60 dB at 1.0 kHz away. Apparently my hearing is very good and can discern a signal at minus 60 dB. All in all, a capable little rig and I really like it, but...(add usual and popular dismay here).
     
  10. K3XR

    K3XR Ham Member QRZ Page

    I don't care for very narrow filtering on CW and use it only because it's sometimes needed. If your interested in the day to day rag chew no contests or chasing DX don't think you will find the bands to be all that crowded considering current propagation conditions. Why not give it a try without the filter see how you do this will also give you a chance to think about how narrow a filter you might want to purchase.
     

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