Can we have a discussion about 2.4ghz?

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by KK4YWN, Jun 21, 2021.

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  1. W4EAE

    W4EAE XML Subscriber QRZ Page

    The LimeSDR is another SDR device with TX capabilities. I have the Mini version which is smaller than its big brother, and can only do 10Mhz-3.5Ghz as opposed to the full 600khz to 3.8Ghz.
     
  2. KK4YWN

    KK4YWN Ham Member QRZ Page



    How do you feel about a qo-100 simulator set atop a mountain ? It would function in the same manner and use the same qo-100 ground station equipment. This approach seems more accessible and would give folks a chance to experiment until a sat can be placed.
     
  3. VE3CGA

    VE3CGA XML Subscriber QRZ Page

    well that would be great for those who live near the mountain but I seriously doubt anyone in this neck of the woods would hit it.
    The only high spots around here (Ontario) are a broadcast tower site in Woodstock, Collingwoods Ski resorts and Hamilton escarpment
    Good out in the rockies for neighbouring states and provinces but thats got to still be a small coverage area.

    I'm still more concerned with interference to and from anyones system in populated areas.
    The cheaper tech may come once its a project.
    I've been surfing around you tube at a few things and there was 1 fellow who briefly mentioned worried about using his small dish to TX and something about the local authorites but I didnt watch it very carefully.
    I'm guessing it will cost over $500 for components, the sdrs for most of the cost and/or a transverter and amp for the tx
    The different transverter options were interesting and certainly 70cm in & out of the shack would be nice but the massive bandwidth of the satellite will probably dictate a higher sdr run with a network connection with everything out at the satellite
     
  4. G0VKT

    G0VKT Ham Member QRZ Page

    A few years ago Radcom had an article on using 2.4ghz video senders for ATV. Paired with a 5w amplifier and a small dish. Super cheap. Range was in the 10s of miles IIRC. It is something I want to try if I could find someone to work with.

    Paul G0VKT
     
  5. SM0AOM

    SM0AOM Ham Member QRZ Page

    2300-2400 MHz has been sold off to 5G in many European countries, and this is also expected to spread to Region 3.

    Another complication is that 2400 - 2450 is ISM and the part of spectrum where WiFi and other low-power "wireless applications" reside.

    This has led to the situation that in some countries the regulators have decided that these applications are "important" and have sided with the WiFi users to prevent interference and degradation.

    In Sweden, as an example, you need a special permit to use more than 100 mW on 2400 MHz, which is very reluctantly issued, something that has been challenged in the courts. Up to now they have sided with the regulator, stating that "the needs of the many have precedence over the wants of a few".

    To get such a permit, usually for 5 or 10 W, you essentially have to live outside built-up areas, and a condition is that the antenna main lobe is pointed well over the horizon.

    73/
    Karl-Arne
    SM0AOM
     
  6. W2EV

    W2EV Ham Member QRZ Page

    Ok. Get ready for useful information from someone who is actually active on 2.3GHz.

    If your interest is narrowband operations (3 kHz or less bandwidth) then you are in for a treat. The jokers who talk about WiFi (a low power service with 100mW of RF spread over a wide bandwidth), cordless phones (really? 1998 called and want them returned), and microwave ovens (on-and-off in a minute or two) are not very helpful...but they are certainly entertaining. :)

    If you live in an area with other operators on 2.3 GHz, then you've got it made. If you don't, then you'll have to assemble two units and can start experimenting to see what is possible in your area.

    Step #1: Get active with adequate power levels. Buy this: http://sg-lab.com/TR2300/tr2300.html
    That is a transverter that can work with a Bo-fang HT to moderate success. It even comes with a small antenna to get you started! If you have the ability to drive it with a low-power SSB/CW radio you will get a 10 dB advantage (SSB shows about a 10dB advantage on the weakest signals).

    Step #2: Refine your station based on your experience experience.
    Antennas are the most cost effective improvement opportunity: https://directivesystems.com/2304-mhz-above/12-cm-2350-2480-mhz/
    If you operate from hilltops (foliage can hurt, btw) and aim across cities...then you are likely to run into many other signals from commercial and residential sources that will require better filtering. However...try first to see what you experience...then...refine.

    Cheers!
    Ev, W2EV
    Rochester VHF Group
    http://www.RVHFG.org
     
    K6CLS likes this.
  7. K3EO

    K3EO Ham Member QRZ Page

    Attached is an article from the July 1995 issue of QST. The author describes a 2.4 GHz repeater system that was used by a dozen or so hams in the San Jose, California area. The technology has come a long way in 26 years.
    Sorry about the poor quality of the image. It is a scan of a copy of a print. If you enlarge it, it should be readable.
     

    Attached Files:

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