Wannabee Ham with a question...SWL?

Discussion in 'Becoming an Amateur Radio Operator/Upgrading Privi' started by RFKID, Mar 19, 2009.

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  1. RFKID

    RFKID QRZ Member

    I am interested in Amateur Radio, but I have always liked monitoring SW frequencies. I can not afford both a SW receiver and a ham transceiver. Which "ham" radio under $1000.00 would be best for SWL?

    Thank you all in advance.

    RFK :confused:
     
  2. K7JEM

    K7JEM Ham Member QRZ Page

    Most newer ham radios have continuous RX from 1.6 to 30 MHz, some well beyond that. You'll need one that has a filter set up for AM bandwidth, if you want the best fidelity.

    Joe
     
  3. RFKID

    RFKID QRZ Member

    Thanks, Joe


    Hi Joe,

    Thanks for the reply. I did know that most ham transceivers have receive coverage from .5 to 30 MHz. I am hoping to hear that there is an affordable transceiver that will avoid the fading that often occurs in the SWL bands. I imagine I would need a 6 kHz filter set-up.

    Thanks again,

    RFK
     
  4. K7KBN

    K7KBN Ham Member QRZ Page

    The "fading" is due to propagation and has nothing to do with the receiver. A gain antenna might help.
     
  5. AE5JU

    AE5JU Ham Member QRZ Page

    Not saying it's the "best" and don't really have much to compare to, but my Yaesu FT-897 (functionally the same as the FT-857) will receive to well below the AM Broadcast (MW) band, up to 6m, 2m, and 70 cm. It will also receive the FM Broadcast band, though not in stereo, of course.

    It seems to receive as well as the Icom R75 receiver I had previously, though I did not do a side by side comparison before selling the R75 to finance the 897.

    I think the Icom IC-718 would receive about the same as the R75, though I don't know just how similar the receive circuitry is between the two.

    I will say this, I've been able to work amost everyone I could hear with the FT-897.

    One thing that really improved this radio was the addition of a BHI, Inc DSP module.

    Paul
    AE5JU
     
  6. RFKID

    RFKID QRZ Member

    I understand about the propagation issue, but...

    I believe that correcting the propagation "fading" has a lot to do with the receiver. If the receiver's synchronous AM detector is good enough "fading" can be very well controlled, and often nearly eliminated. If ICOM had not removed the synchronous AM from the R-75 I would purchase one of those and send it to Craig for the Kiwa mods.

    But, alas, ICOM deleted it from the R-75 because the R-75 could not hold lock. It is too bad that ICOM didn't improve the lock loop rather than just deleting it from the receiver. This "downgrade" by ICOM is what prompted my original question about ham tranceivers. I can't afford to purchase a ham transceiver that doesn't have the capabililty of controlling "fading" AM signals.

    I can not utilize a gain antenna at my home.

    Thank you for replying.
     
  7. KB3LAZ

    KB3LAZ Ham Member QRZ Page

    Actually in your price range you can.

    Receiver
    http://yaesu.com/indexVS.cfm?cmd=Di...0D97AA88D73437C52D&DivisionID=65&isArchived=0

    Transceiver
    http://icomamerica.com/en/products/amateur/hf/718/default.aspx

    Neither of which are the best in their class but they are both good reliable pieces of equipment. The total cost would come out to be a bit more than you quoted but you could always get them used.

    Now if you want something with a bit more pizazz you're either gonna have to change your price range or go used.

    Personally this is my fave but now we are diving into the realm of fantasy.
    http://icomamerica.com/en/products/receivers/tabletop/r9500/default.aspx
     
    Last edited: Mar 21, 2009
  8. NA0AA

    NA0AA Ham Member QRZ Page

    An FT-897 does pretty well for an all-band, and it's not terribly expensive.

    AM is not really a great feature on most radios, but since AM is usually broacast SW, signal strengths are high - and the 897 also receives LW pretty well.

    Also, since it has two meters and 70 cm also built in, once you DO get your license, you will be ready for tech privilages by installing a suitable transmit antenna.
     
  9. AI3V

    AI3V Ham Member QRZ Page

    :D
    Your beliefs about HF fading, and the role of a synchronous detector are incorrect.

    The synchronous detector will only have an effect for ONE particular type of fading called SELECTIVE FADING.

    When a signal is reflected in the ionosphere, the different frequency's (the carrier and sidebands) are delayed by different amounts of TIME.

    These different TIME delayed signals will combine in your receiver, and if delayed by 1/2 of a RF cycle, will combine destructively.

    A signal can have a "slice" taken from it, due to this effect.

    If the "slice" is on one of the two sidebands, the ordinary AM detector will still output a signal, but at a slightly (3DB) lower volume.

    If the "slice" happens to fall on the CARRIER frequency, Than a ordinary AM detector will fail, and output nothing but distortion, as the radio tries to demodulate a signal without a carrier.

    The synchronous detector is a PLL (Phase Locked Loop), tuned to the carrier frequency (as translated to the intermediate frequency) of your receiver,The output of the PLL is a steady signal that exactly matches the frequency of the carrier as broadcast.

    The time constant of the PLL is such that the receiver will not try to search for the carrier for several seconds, enough time for the ionosphere to change again, and the carrier to be un-faded :D

    For the much more common ordinary fading, Where the ENTIRE signal fades into the noise, a synchronous detector is worthless.

    Rege
     
  10. K0RGR

    K0RGR Premium Subscriber QRZ Page

    The only ham rigs I'm aware of with Synchronous AM detection are the software defined radios from Flex Radio Systems. The PowerSDR software includes a number of features for AM SWL reception, and the hardware on their new mid-price radio (under $1600) has separate bandpass filters for the shortwave bands.

    http://www.flex-radio.com/Products.aspx?topic=powersdr1x

    In addition to the radio, you also need a fairly powerful PC and very good soundcard to run the software.

    I know this is a bit more than the price range you were considering, and if you don't have a PC with sufficient capability, there will be more expense.
    And, the Flex rigs have not been highly recommended for beginners in the past. But if you truly want first class everything, this may be your solution.
    The Flex 5000 - their top of the line - is quite a bit more expensive.
     
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