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Why I need a HF Amplifier

Discussion in 'Ham Radio Discussions' started by N8FVJ, May 16, 2019.

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  1. N8FVJ

    N8FVJ Ham Member QRZ Page

    I have read the statement 'I do not need a HF amplifier'. Some hams take pride in using 100 watts power only from their HF transceiver. Myself, I would lose many contacts when the bands are less than great condition with only 100 watts output. Using 750 watts PEP out, some contacts I make are only one S unit above the noise, but solid copy. Some contacts do not hear me even at 750 watts PEP out. Using 100 watts I would never be heard on less than great band conditions. Low power is not for me.

    I do not own an expensive beam antenna on HF bands and the associated tower. 40 thru 10 meters with high gain beam antennas would work like an amplifier, but a 40 or 75 meter beam is out of consideration. A tower and 20-10 meter beam with rotor would cost more than my amp and modern transceivers with DNR hear SSB very well off of a wire antenna.

    I cannot imagine not owning a HF amplifier. I consider 750 watts PEP the minimum reasonable power output and 1/2 legal limit power output amplifiers do perform off of a convenient 120 volt AC wall outlet (240 volts AC not required).

    How about yourself?
    Last edited: May 16, 2019
    MM0IMC, NQ1B and W9FL like this.
  2. K8JD

    K8JD Ham Member QRZ Page

    Why you need an amp ? because you do not have a good enough antenna !
    Better antenna will let you hear weak signals btter too !
    W0FS, NK2U, K9CPO and 13 others like this.
  3. AA5CT

    AA5CT Ham Member QRZ Page

    re: "How about yourself?"

    EVEN with a good antenna on 160, from a small lot, to be heard in the northeast on 1900 kHz an amplifier (with that extra 10 dB of signal boost) is required ... sure, there might be isolated points in time where 100 Watts can be heard, but those are the exception rather than the rule.
    K8AI and WD4IGX like this.
  4. AA5CT

    AA5CT Ham Member QRZ Page

    re: "Better antenna will let you hear weak signals btter too !"

    Pulling in *more* signal and noise does not equate to improving the signal to noise ratio; Now, moving to a directive antenna (a beam) removes some of the noise, so, that is a solution to improving the signal to noise ratio.

    And, of course, there are receive-only antenna solutions that provide that needed directivity to improve signal to noise ratio.
    WA7PRC and WD4IGX like this.
  5. W1VT

    W1VT Ham Member QRZ Page

    I've gotten a lot of contest certificates in the QRP and low power categories. In 2014 I got certificates for running low power in both the CQ WW 160M contest, CW, and the ARRL Sweepstakes, CW.

    But, I do need an amplifier for harder DX contacts, like working New Zealand on 160M with a 36' high Inverted-L. Australia is farther, but NZ is a tough distance with far fewer band openings.
    Last edited: May 16, 2019
  6. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    My observation, also -- except for during the 160m contests, or major DX contests using 160m.

    Under those conditions I'm always amazed by the "ears" of the big-gun stations. I can run a kW on 160 (compromise antenna due to small lot -- it's a trapped 80/160 inverted vee with apex at only 55' so it's kind of a cloud warmer on 160), but due to the functional bandwidth of the antenna and also the amplifier tuning (tube type) that requires re-tuning if I QSY more than about 30 kHz. That's not much fun, so I generally kill the amp and just run barefoot using the auto-tuner in my rig, which takes about one second to re-tune and maintain 100W output.

    And doing so, just about every single "big gun" I call hears me fine, even if they're nearly in the noise at my end. Those guys have amazing RX antennas and stuff and seem to hear a pin drop. Some of the DXpeditions to islands in the middle of nowhere are often similarly blessed, probably because they have no local noise level to deal with.

    But without a contest when the band is populated by more "average" or "below average" stations, they DO NOT hear me with 100W, and the amp goes back on line.
    WA9SVD, WA7PRC and WD4IGX like this.
  7. K1VSK

    K1VSK Ham Member QRZ Page

    It’s easier on CW. Or some of the fashionable digital modes. But having more power can sometimes make it easier which may be a priority for some.

    I’m sure newer hams don’t like hearing this but as aNovice, rock bound, frequency limited, with less than 75 watts to dipoles during a prior solar minimum using receivers with far less dynamic range, stability, sensitivity, etc... it wasn’t uncommon to work anything once you develop the skill.
    KD7ORN, W4NNF, N4NYK and 3 others like this.
  8. N3AB

    N3AB Platinum Subscriber Platinum Subscriber QRZ Page

    I don't consider 100 watts "low power". I ran 5 watts with an FT-817 and worked a lot of DX. Never owned an amp, and never will.

    A better antenna doesn't necessarily mean more noise.

    I love some of the guys on 75 claiming signal reports of 20 or 30 dB over 9, and are so glad they are running a kilowatt.

    So much for running the least amount of power to maintain a contact.
    W4RAV, K4AGO, WQ4G and 4 others like this.
  9. W2JKT

    W2JKT Ham Member QRZ Page

    I've been doing a lot of digital lately and have not needed an amp to work countries all over creation.

    SSB is still another story though. The other evening I tried and tried in all futility to work a station in Venezuela. I must have answered for half an hour on 100W before finally giving up and flipping on the amplifier. 1kW got me me the contact on the first try.

    Sometimes it just comes in handy.
    NQ1B, W4IOA and N4NYK like this.
  10. W1VT

    W1VT Ham Member QRZ Page

    I received two contest plaques for running QRP in 1994.
    QRP Phone in the ARRL Sweepstakes
    QRP Portable in the June VHF contest, First Place.

    J6/W6JKV was worked with 5 watts on 6M phone with a homebrew rig/yagi
    KD7ORN, K4AGO, K8AI and 1 other person like this.

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