Non-resonant loop receive strength

Discussion in 'Ham Radio Discussions' started by W1DH, May 10, 2019.

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  1. W1DH

    W1DH Ham Member QRZ Page

    Hi everyone,

    I've been working a lot of CW lately. I've been trying to get away from my old method of using the S-meter for RST reports, as I've read this is not best practice. I've also started running my RF gain dialed down which makes the S-meter useless.

    As 20 meters has been open the past week, I've been running my 80 mtr loop on 20 meters with my tuner. It tunes up just fine. I worked a handful of DX in Europe and South America and for the most part have been getting reciprocal signal reports unless the other end is QRP, running indoor/apartment antennas, etc. Tonight I worked a station who I estimated about a 569. He had a good signal, but compared to the 7/8 land stations I'm used to hearing boom in on 40 meters, he was lower. He gave me a 599 report. He stepped an amplifier on and off, explained that he has a yagi antenna setup, and said the issue must be my end and I needed to get a better antenna to run 20 meters. The QSO then ended.

    My question is, is there a possibility of me being an 'alligator' station (all mouth no ears) running a non-resonant loop at 100W? Or, is it possible that propagation is stronger one way versus the other on a band like 20M at the gray line near sunset? It was dark here, and still light where the other station was. I've played with the online SDRs and it seems to me like I have good reception on 20 meters with the 80 meter loop.

    Thoughts? Thanks.
  2. K1VSK

    K1VSK Ham Member QRZ Page

    Books have been written on the reciprocal propagation myth. It is, like any generality, usually untrue. No doubt opinions vary.
  3. K7TRF

    K7TRF Premium Subscriber QRZ Page

    Those are definite possibilities but the big possibility is that you have more local noise sources and or your antenna is down closer to those noise sources than his Yagi up high. Also a Yagi has directivity and though a lot of hams think about that in terms of dB of gain, perhaps the most valuable thing about a directional antenna is attenuating the noise coming from directions other than where it's pointing. IOW, in addition to getting an antenna up high to minimize noise a directional antenna's directivity decreases both the band noise and QRM/QRN coming from directions off the back and sides of the beam. That's sometimes characterized as Receiving Directivity Factor (RDF) which basically translates to improvements in Signal to Noise ratio unless your primary noise sources are in the same direction the antenna is currently pointing and receiving is all about S/N.

    Basically all the things you mentioned are possibilities but often the reason for different signal reports on either end of the QSO is differences in receive noise for each station and there's several things that can impact that in addition to high vs low antennas.
    KA4DPO, K3KIC and K2XT like this.
  4. WZ7U

    WZ7U Ham Member QRZ Page

    Just pass out honest evaluations at your end and don't worry about it. There are too many variables in the circuit from one station to the next to get all hung up on it. I'm glad to hear your 80m loop is working great on 20m, it gives me hope for what to expect here. Even if I do have that giant rock hill directly to my east literally right next door.
    KK5JY likes this.
  5. W1DH

    W1DH Ham Member QRZ Page

    It may be local noise, it’s hard to tell. I’ve heard the TS140S I use is a very sensitive receiver, but I am on a borderline industrial area.

    As an example right now, full RF gain, wide CW filter, S4-5 noise level on 20M. Narrow filter (160 hz) shows S1. With ANC4 on, S3 wide filter, <S1 narrow filter.

    Someday I’ll put up a nice hex beam for 20 up. For now I’m just having fun. Or I can contest and we can all “599 AGN PSE.” :)
  6. KK5JY

    KK5JY Ham Member QRZ Page

    What @WZ7U said.

    It's not at all impossible for you to hear a 100W station with a dipole booming in, but a kW-class station with huge antenna maybe half-scale, even if they are at similar distances. Propagation is complex, and never equal over any two paths. Add to that the pattern shapes and angles of the antennas involved, types of antennas, types of ground quality, etc., it's all just a coin-toss.

    You can be an alligator station at 100W, but you probably aren't. One way to get a rough evaluation of your TX vs RX performance is to check spotting networks. If you see your transmitted signal being heard by many stations at distances beyond what you can hear, then you might be a little alligator-ish. But remember, dropping one S-unit from 100W takes you down to about 25W, so even if you are an alligator, you aren't an alligator by much.

    Okay, back to calling CQ. :)
    KA4DPO likes this.
  7. K7TRF

    K7TRF Premium Subscriber QRZ Page

    Just about any ham receiver designed in the past 50 years is more than sensitive enough compared to band noise. The simple test is to disconnect your antenna feedline from the back of your receiver and listen to the noise coming out of the speaker, if the noise jumps up when you reconnect the antenna then more sensitivity won't do you any good at all.
    Yeah, more sensitivity won't do you any good at all and your receiver is more than sensitive enough as it is.
  8. KB9BVN

    KB9BVN Ham Member QRZ Page

    Just tell them 599 and keep on QSOing.
  9. W5TTP

    W5TTP Ham Member QRZ Page

    Hmmmm, 569 vs. 599. Despite the increased investment in antenna and equipment, the other station may be suffering from a relatively new disease. That is "dot (or dash) deficiency syndrome". DDS has been becoming more noticeable in recent years. It is mainly noticed during cw (that is Morse code based) contests. This syndrome has also migrated in a mutant form to voice based contests and contacts. The current belief is that both can be cured, or at least dealt with, by the sender of the less than 599 reporting originator. Sit back, take a deep breath, maybe a sip of red wine, and continue with the communications as if nothing happened.

    Signal report egos are directly relational to the size of the operators mothers basement. Or, so I have heard. :)
  10. WF4W

    WF4W Ham Member QRZ Page

    i've never cared. Did this guy seriously get bothered by not receiving a 599??

    signals reports are subjective and a function of both the sender and receiver. I handed out a 559 yesterday and got a 339 back - It never even crossed my mind that i should i have been higher as I just assumed the other stations antenna was compromised. . . plus I'm using a vertical so I never expect good signal reports anyway :p

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