Elecraft K4

Discussion in 'Ham Radio Discussions' started by W6RZ, May 16, 2019.

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  1. SM0AOM

    SM0AOM Ham Member QRZ Page

    Of course, the dynamic range can be substantially improved by using a
    signal-matched filter at the receiving end.

    But anyway, there is a limit to the improvement possible which will be ultimately governed
    by the long- and short-term dispersion properties of the ionospheric channel.

    It also depends on the actual dynamic range that are required for meaningful interpretation of
    the IM and adjacent channel products. Today's transmitters may require 40 dB,
    but the hopefully better ones of tomorrow may require 50 or even 60 dB.

    The HP141 systems, however nice, have since long been retired from my own home lab
    and were replaced by the Rohde&Schwarz FSIQ and FSEB.
    They have a lot better stability properties and dynamic range...

    73/
    Karl-Arne
    SM0AOM
     
  2. W1VT

    W1VT Ham Member QRZ Page

    What some posters with access to expensive test equipment don't realize is that most hams don't grok numbers.
    Now that hams can see good and bad stations on their panadapters, they can now grasp the importance of having a clean transmitter if you are loud. Doesn't matter if nobody can hear you.

    Ironically, panadapters were popular but went away as manufacturers chose designs that would improve receiver dynamic range. The tight filtering right after the first mixer would not support an inexpensive panadapter. But, SDRs will support both an inexpensive panadapter and a quality receiver. So now everyone has a panadapter and can see what a bad transmitter looks like on the air!

    So the question now becomes, how many will buy a new rig just for having a better ergonomics and improved transmit quality if there is little to be gained on the receive side?
     
    N2EY likes this.
  3. N2EY

    N2EY Premium Subscriber QRZ Page

    Yes and no.

    The Big Question is: What is a "good transmitter" and what is a "bad transmitter", and who decides?

    In the early days of SSB, phasing type transmitters were popular. With the techniques usually used by hams, unwanted sideband rejection of -40 dB across the 300-3000 Hz audio passband could be achieved.

    In real life, somewhat less (-35 dB or so) was the usual result. This was due to the characteristics of the RC audio phase shift networks used. And if the audio extended beyond the 300-3000 Hz design passband of the audio phase shift networks, the rejection was a lot less.

    Is -35 dB unwanted-sideband rejection a good transmitter or a bad transmitter?

    If an SSB transmitter has -40 dB unwanted sideband rejection, and the desired sideband is heard at S9+20 dB at a particular location, the unwanted sideband will be heard at S5-1/2 or so. Whether that's a problem or not depends on who is trying to use the spectrum occupied by the unwanted sideband.

    73 de Jim, N2EY
     
    N2SR likes this.
  4. W4PG

    W4PG Super Moderator Lifetime Member 279 Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    I'm not sure what it means to "grok" numbers, but I think I can imagine. My TS-990 is way down the list when it comes to narrow spaced DR but I prefer it over my Flex 6700 for day-to-day operation (which by Sherwood is much better). As someone else mentioned I doubt I can even tell the difference between the two with my ears, which is more important to me than some number on a scope. There are MANY other factors that go into rig happiness.

    But, to each his/her own. What-ever floats your boat. I'm really looking at the K4, never having paid much attention to Elecraft. I played around with the prototype at Dayton and it was very cool!

    ...............Bob
     
  5. W3KHG

    W3KHG Ham Member QRZ Page

    Thank you Carl!
     
    KM1H likes this.
  6. AF2Z

    AF2Z Ham Member QRZ Page

    Usually they will ship a part to you so you can replace it yourself without need of returning the rig.

    That's one reason I do favor Elecraft: there is very little chance that I'll ever have to return the rig to the factory for service, either for repairs or upgrade mods. I have done both over the years on my early model K3 including a cracked knob, a board socket (replaced with upgraded gold plated ones), and several hardware mods-- all for free.

    I bought a used interface board from another ham that was supposedly functional but was either defective or damaged by static in shipping. Consulting with Elecraft they pointed me to the likely fault which I then repaired cheaply & easily.

    I upgraded my K3 to higher performance when a better synthesizer became available after several years. I expect I'll be able to do the same with the K4 when better ADC devices become available.
     
    N0TZU likes this.
  7. WN1MB

    WN1MB Ham Member QRZ Page

    From WordNet (r) 3.0 (2006) [wn]:

    grok
    v 1: get the meaning of something; "Do you comprehend the
    meaning of this letter?" [syn: {grok}, {get the picture},
    {comprehend}, {savvy}, {dig}, {grasp}, {compass},
    {apprehend}]
     
    W4PG likes this.
  8. WF7A

    WF7A Subscriber QRZ Page

    It's a neologism from sci-fi writer, Robert Heinlein, in his book, Stranger in a Strange Land.

    I is literate. : )
     
    N3AWS, N4XRD, WN1MB and 1 other person like this.
  9. KP4SX

    KP4SX XML Subscriber QRZ Page

    Now I have to go look up neologism :confused:
     
    WN1MB likes this.
  10. W7UUU

    W7UUU Super Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    DING DING DING!

    Otherwise, no one would ever bother playing with a Henry Radio Temp One, Eico 753, HW-16, HW-7, or the myriad other fun old radios made over the years that would never ever ever have appeared on the Sherwood list

    :)

    Dave
    W7UUU
     
    N0TZU likes this.
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