Recommend an HF radio

Discussion in 'Ham Radio Discussions' started by VE3GZB, Dec 1, 2019 at 5:52 PM.

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  1. VE3GZB

    VE3GZB Ham Member QRZ Page

    Ok my first posting seems to have grown a few heads and wandered off track to some degree. Perhaps my question was too vague. I'll try asking again.

    I presently use an IC-7300 mainly for digital modes such as FT8. On occasion I've taken it on vacation up north where I used it on phone and/or digital modes.

    The small size is very convenient. But after owning it for a couple of years I'm seeing some receiver limitations regarding noise and overload.

    I live in the south end of the city. Just beyond the north end of the city a ham lives there on a rural property with an impressive antenna farm and probably with equally impressive gear. When he comes on the air the IC-7300 goes into overload on receive in digital mode where AGC should be off.

    So I'm thinking that it might be good to sell/trade the IC-7300 while it may still have value and "upgrade" to something else with better receiver performance, even if such an "upgrade" may be chronologically backwards.

    I remember owning an FTdx1200 and I remember being impressed with the quiet nature of the receiver. I've been hearing things about the IC756Pro-series but don't know enough to really decide.

    My budget would be probably under $1000 cash or a combination of some cash + trade.

    Please share your recommendations.

    73s
     
  2. M0GVZ

    M0GVZ Ham Member QRZ Page

    The only things with better receiver performance you'd actually notice are the Yaesu FTDx101, Elecract K3S and Flexradio 6700 and even then they're only better for selectivity. When it comes to receiver sensitivity, the ability to hear weak signals, ALL RADIOS made in the last half a century are more than capable of hearing below the noise floor on the quietest place RF wise on planet earth.

    If you're wanting to upgrade your radio to get one that can magically bring stations out of the noise better than another radio you'll be sorely disappointed as it doesn't exist.

    Where the hell do you get that idea that you should be turning the AGC off? And even if you do then you should be operating the radio properly for a radio without AGC and to do it properly that means what you have to do is manually control the RF gain, altering it and the AF gain on a very regular basis during use which can mean as much as every time you have a new contact or every time there's a new signal broadcast nearby. The whole reason AGC was invented and applied to receivers was to improve the situation where you'd have to alter both AF and RF gain for every contact in a radio pre-AGC. No matter what radio you have, if you have the AGC turned off and that ham keys up it is going to overload the front end of your receiver unless you wind back the RF gain when they transmit.

    In short the only reason you're getting overload is because you're not operating the radio properly. With the AGC turned off you should hardly ever have the RF gain near full on and on HF the pre-amp is a button that should never be used, regardless of the band you're on.
     
    Last edited: Dec 1, 2019 at 7:01 PM
    N8ZL, W9FL, AA4MY and 1 other person like this.
  3. NL7W

    NL7W Premium Subscriber QRZ Page

    Selectivity... maybe.
    The receiver performance characteristics that will drastically improve will surround receiver overload improvements, monitoring multiple, wide swaths of spectrum chunks, noise reduction capabilities, and screen resolution, amplitude and frequency range. Others will chime in as well, I suppose.
     
  4. KK5JY

    KK5JY Premium Subscriber QRZ Page

    There are relatively few current-production radios that have better receiver specs than the 7300, and basically none in the price range you named, unless you are willing to go QRP. You're already close to the top of the list. :)

    I'm not sure what you mean by "noise" problems, but most transmit antennas generate way too much signal for modern receivers. The solution for overloading is to use an attenuator, either the one built in to the radio, or an outboard attenuator in the RX signal path, to bring the received energy levels down to a more manageable level. There is an inexpensive plug-in kit available for the 7300, that will let you put an attenuator (or anything else) in the RX signal path, and an inexpensive step attenuator from MFJ will let you pick just about any reasonable attenuation value you like.
     
  5. KN4CQB

    KN4CQB XML Subscriber QRZ Page

    Could also be your antenna and the way your pre-amps are set. Also use the automatic notch filter. I love my 7300 and other than band conditions I do not consider it a "noisy" radio
     
  6. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    You already had one of the best lower price radios that you can buy. Did I wouldn't even think about going back to 756 Pro, it's like three generations old now.
    Besides the above comments, You might check on how you using the " IP plus" function most people going from analog radios to the 7300 or 7610 don't understand how it works) also on lower frequencies instead of using preamps, SDR Radio actually work better with some attenuation.
     
    W4NNF and KK5JY like this.
  7. W4NNF

    W4NNF XML Subscriber QRZ Page


    Before you spend money, try a couple of things. First, AGC does NOT have to be off for digital modes. Set it to "fast" and see how that works. Works fine for me. Also, you can try the IP+ function.
     
    W9FL likes this.
  8. VE3GZB

    VE3GZB Ham Member QRZ Page

    AGC fast isn't good. I tried it this way when I was getting into digital modes.

    I found that (and other hams advised me correctly in this) AGC really has to be off because a local ham's signal or local heavy QRM is so strong at times my receiver's gain gets pushed down and I lose the DX signals I'm trying to chase.

    If I want to catch DX I don't need the AGC to react and kill the radio's gain when a stronger signal comes by. Or when there's lot of QRM here as it often occurs.

    I tried the IP+ function and it's insufficient to help in this case. It has a small effect - but some very ugly broadband QRM here as well as the signals from the ham north of me.

    Either way, whether it's QRM or something from a local ham - it's still a strong signal overloading the receiver to the point where the red "OVL" light flashes on the screen.
     
  9. KK5JY

    KK5JY Premium Subscriber QRZ Page

    There's really nothing any radio can do with this. All of them will saturate if enough adjacent signal is present with AGC off. The 7300 saturates differently than conversion radios, because of its design, but all of them will eventually be driven into distortion if the AGC is off.

    For anything but voice, I use a mid- or slow-AGC, but that's my preference. I also use generous attenuator settings. If the S-meter is moving on nothing but background noise, you have too much receiver gain, and you will reach "overload" or clipping sooner than necessary. Dropping the RF gain of the receiver (regardless of the design) to the point where the antenna sets the noise level in the receiver, but no more, will give you the optimal dynamic range, and the most headroom before overload, AGC activation, or clipping.
     
    WD4ELG, W9FL and AA4MY like this.
  10. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I think there are lots of better receivers than the IC-7300. "Sensitivity" has nothing to do with it; but putting RF selectivity where it needs to be helps a lot, and the 7300 doesn't offer such an option.

    Big-gun contesters with big antennas on big towers, the kind who actually "win" the HF contests, aren't using 7300s.

    I'd agree a used K3 which "might" be available for $1K or so is a better choice for many situations. There's nothing "new" in the $1K range that offers roofing filters and all the stuff really needed to deal with very strong signals on crowded bands and also has good noise rejection capability.

    I have a really simple test for all kinds of HF rigs and it only takes about a minute: I set it down on the bench next to my other rigs, connected via an antenna switch, and aim my HF beam towards KVOH, a 1.25 megawatt SW-BC station only a few miles from me. If that creates desensitization, images, a raised noise floor and other issues that are really obvious quite quickly, it won't survive well operating from this location.

    My 41 year-old TR-7 passes this test easily; can't even tell the BC station is transmitting.

    When I tried this with a borrowed IC-7300, it failed the same test immediately.:)

    Not many live so close to a megawatt-level SW BC station, but many do live close enough to "legal limit" HF ham stations that can create similar problems.
     
    K8AI likes this.

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