Yaesu ftdx 3000

Discussion in 'Amplitude Modulation' started by N2DTS, Aug 21, 2019.

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  1. N2DTS

    N2DTS Ham Member QRZ Page

    I picked one of these up and have been checking it out on AM.
    The hand mic sounds nasty, but using the line in and out audio the audio sounds very good RX and TX within its bandwidth limitations.
    The audio sounds clean and clear, receive audio is nice, its got what they call 6 and 9 Khz bandwidth choices.
    The width and passband tuning controls do not work on AM, why I do not know, not important enough to add I suppose...or maybe its the design.
    It has a 9 MHz first IF and the radio has an IF output that allows a NICE panadaptor. I hooked up my sdr-iq and it allows a 190 KHz display if you want it that wide, along with all the sdr features.
    TX audio sounds very good to me, it goes out to about 3 KHz or maybe wider, but it modulates well, 100% in both directions, and it will over modulate in both directions.
    It does not seem to sound bad when you do over modulate, nor does it get warm if you run it at full power for a while, no loud fans.

    Controls are semi nasty with not enough buttons, but you can manage.
    The tuning knob is very touchy and there is nothing you can do about it.

    The built in spectrum/waterfall display would have been very cool about 25 years ago, today its a waste of time.
    Its got three antenna ports, #3 can be a receive antenna port or a TRX port, the built in antenna tuna works on all 3 ports withing the typical 3-1 range.
    The receive audio sounds much better then the icom 7300 as it goes below 100 Hz, and the TX AM is better as far as modulation goes, easy to hit 120% or more positive.

    I worked Joe (N4RXV) down in Georga for an hour last night on the 3000 at 25 watts carrier into the G5RV antenna solid copy both ways, when I went to the 200 watt rig I came up 2 S units he reported.

    These radios are about half the cost they were when they came out, maybe the icom 7300 has caused that.
    For the price (new) they seem worth it for this kind of radio.
    It does not TX 5000 Hz but otherwise sounds very good to me for a modern plastic box radio.
    Its not as fussy in adjustment as a flex 5000, it modulates better then the 7300 and the RX is MUCH better sounding.
    You could put a good microphone in the front and use the built in EQ and have a better sounding AM box then most others..
  2. WA4JK

    WA4JK Ham Member QRZ Page

    I have one as well and using a girl fin input to the front I get very good audio reports on AM. It’s a lot quieter on receive with the 9Mhz input. It will be the high band AM xmitter.
  3. N2DTS

    N2DTS Ham Member QRZ Page

    I hooked up a condensor mic I was using on the Flex and adjusted the EQ in the radio and it sounds quite good for the limited response allowed.
    Not a bad radio if you don't have to sound like a broadcast station.
    The RX audio sounds great to me.
    If I listen to myself in the built in monitor and then the homebrew RX output, they sound the same.
  4. K4KYV

    K4KYV Premium Subscriber QRZ Page

    By "overmodulating" in the positive direction, do you mean the audio can be driven to flat-top on positive peaks, or that the undistorted positive peak modulation capability exceeds 100%?
  5. N2DTS

    N2DTS Ham Member QRZ Page

    It does not flat top.
    It folds back around in the negative direction like most/all sdr radios.
    I wonder if that is worse then closing down the carrier like a plate modulated transmitter does or better...

    Of course, you can adjust it to run 15 watts carrier and hit peaks of 100 watts, or run 30 watts and hit 100 watt peaks, but running 25 watts carrier
    seems to give 120% positive with no problem.
    Not sure how calibrated the watt meters are...
    Anyway, unlike a lot of modern type radios, it does seem to allow plenty of audio on the carrier which is rare.
    The Elad fdm duo modulated nicely up to 100%, the Elecraft stuff had a problem, as did the TenTec rig.
    The Icom 7300 modulated ok to about 100% and sounded ok, the rx audio had no low end.

    These types of rig make good exciters for the big rigs or good rigs for 20 meters up to 6.
    Some of the receivers are good for AM, others not.
    The Elad fdm duo was a very nice AM receiver for its size.
    The ftdx 3000 sounds good on RX but the filtering is not sdr good.
  6. K4KYV

    K4KYV Premium Subscriber QRZ Page

    If I understand correctly what you mean by "folding back", instead of closing down the carrier beyond 100% negative modulation it keeps on producing RF, but as soon as it crosses baseline the RF is reversed to 180° out of phase from the normal carrier. AKA double sideband reduced carrier. This produces somewhat worse distortion than regular overmodulation on a diode detector, but if everything is properly balanced and linear, there are no additional spurious distortion or splatter products beyond that of a normal AM signal. This is identical to the signal produced by the "upside-down tube" circuit of W3PHL fame, which was merely a high-level balanced modulator. The distortion closely resembles what you hear with selective fading on a regular AM signal and diode detector. Synchronous detection demodulates it perfectly without distortion. If the amplitude of the steady carrier is dropped to zero, the result is DSB suppressed carrier. Unlike SSB suppressed carrier, to properly demodulate DSBSC, the re-inserted carrier must be precisely on frequency and in phase (or 180° out) with the original carrier, which is the function of the specialised version of the synchronous detector called a Costas Loop.
  7. N2DTS

    N2DTS Ham Member QRZ Page

    Thanks for the info Don.
    Yes, that is what it does, instead of flat lining, it starts making a bump of RF on the scope.

    Unlike a lot of modern radios, it will allow over 100% if you run it that way.
    The radio seems to sound very clean up to 100% modulation and its not fussy.
    My flex 5000 is a bit fussy and hard to get it to sound clean for some reason.
  8. N2DTS

    N2DTS Ham Member QRZ Page

    I found out there is a way to make the TX audio response out to 4 KHz, I will have to see if it works on AM.
  9. KA4KOE

    KA4KOE Ham Member QRZ Page

    Yes, its in one of the menus. Let us know the results please.
  10. N2DTS

    N2DTS Ham Member QRZ Page

    It works on ssb but not AM....
    3000 Hz audio is the most you can get out of it.

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