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  • Conversion up or down?

    From Holger Granholm@2:20/228 to Richard Menedetter on Fri Sep 2 09:41:00 2016
    In a message on Friday 09-01-16 Richard Menedetter said to Holger
    Granholm:

    Good day Richard,

    An Upconverter is needed to convert a lower frequency signal to a
    higher frequency signal.

    OTOH, a downconverter is needed if I want to use my FT-290 VHF (144 MHz) transceiver to send on the HF (SW) bands. That is what my 'Tokyo HI-Power VHF>>HF Transverter' does.

    IOW, converting the 144 MHz signal to for example 14 MHz.

    See also the descritpion for the Ham-it-up upconverter:

    It seems that the convention is the other way around.

    You are actually converting down the receiving frequency band to be able
    to receive frequencies below the 25-1300 MHz band, that the thumb-stick
    is designed to receive.

    Yes it seems that the Ham-it-up that you are referring to, has got the convention on the back foot.

    In all my life as a HF-VHF-UHF-SHF ham, I have built converters to be
    able to receive VUSHF, on for ex. 28 MHz.

    That is downconverting, ie. converting the 144 MHz signals to 28 MHz.

    When I wanted to use my Drake TR-4 transceiver to transmit on 144 MHz,
    I needed an upconverter.

    So, finally it all depends upon from which viewpoint you look at it.


    Regards,

    Holger

    ---
    ■ MR/2 2.30 ■ And on the 8th day God said, "OK Murphy, you take over"
    * Origin: Coming to you from the Sunny Aland Islands. (2:20/228)
  • From Richard Menedetter@2:310/31 to Holger Granholm on Sun Sep 4 21:01:58 2016
    Hi Holger!

    02 Sep 2016 09:41, from Holger Granholm -> Richard Menedetter:

    So, finally it all depends upon from which viewpoint you look at it.

    Exactly!

    CU, Ricsi

    --- GoldED+/LNX
    * Origin: Blaming others can become a satisfying way of life (2:310/31)
  • From Tony Langdon@3:633/410 to Holger Granholm on Mon Sep 5 08:56:00 2016
    Holger Granholm wrote to Richard Menedetter <=-

    So, finally it all depends upon from which viewpoint you look at it.

    No, it's simple. If the output frequency is lower than the input (e.g. 1296 MHz in, 28 MHz out), then it's a downconverter. If the output frequency is higher than the input frequency (e.g. 136 kHz to 3.5 MHz), then it's an upconverter.

    That rule works whether you're transmitting or receiving.

    So the "Ham It Up" and other converters used to receive HF on a RTL-SDR dongle are up converters, since they convert the 0-24 MHz range into something higher than the stick can receive.


    ... Don't Panic! It's only ones and zeros.
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    * Origin: Freeway BBS - freeway.apana.org.au (3:633/410)