1296 lobuck station build

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by KK4YWN, Nov 13, 2017.

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  1. W0AAT

    W0AAT XML Subscriber QRZ Page

    $199 + shipping and good reviews. Haven't got mine on the air yet(still building other bits and pieces like the 300 watt amp, yes I am looking at EME capable in a year) http://www.sg-lab.com/TR1300/tr1300.html

    144mhz IF which is really easy these days with any number of DC to 70cm radios. For Tropo the plan is a pair of 23cm35 yagis from M2 because I know they will survive the ice and wind I see every winter. Still need some hardline to run to them, get the tower up on my deck(15' of Rohn 25)... but getting there as money allows.
     
  2. WB3BEL

    WB3BEL Ham Member QRZ Page

    I would start with only one antenna. Combining just adds complexity you don't need to get going.
    I'd build a medium boomlength Yagi or 1296 MHz Loop Yagi not Quagi. There are plans if you do search.

    I would take it to a higher site during a VHF/UHF contest and try it out.
    below roofline or through lots of trees is a huge disadvantage.

    W1GHz has a clever idea for filters here. These can go post LNA. For LNA minicircuits PGA-103+ is cheap and low noise.

    http://www.w1ghz.org/filter/Altoids_Tin_Filters.pdf
     
  3. KE8AKW

    KE8AKW Ham Member QRZ Page

    I am considering setting up a 1296 station one day. Would probably buy a SG Labs Transverter and use that to drive a DEMI amp to around 30-60w probably into a Loop Yagi or something like that. Being considered for satellite use also as some upcoming satellites will have a L-Band Uplink for the FM repeater. I have heard from several big VHF op's that 1296 has the most activity out of all the microwave bands during contests! Unfortunately to get all that i have listed above it would be close to $800 to get a nice station on 1296!
     
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I never used and don't know about SG Labs transverters...but my amp is a pair of 3CX100A5s (ceramic 2C39) and runs 100W PEP output on 1.2 GHz and cost almost nothing to build. The tubes are very cheap and the GG amp has 10 dB power gain, so 10W in =100W out. Sockets could be potentially homebrewed, although I never did that, I got them from surplus TACAN gear which is still readily available; building the output cavity is just "mechanics," so anyone good with tools can do this.
     
  5. W1GCI

    W1GCI Ham Member QRZ Page

    I lost my 90 foot tower a few years back in an ice storm and never put back my 903, 1296, or 2304 antennas. The landscape for operation on those bands is now changing and I doubt that I'll ever get QRV there again. Since these bands for me were strictly used for contesting, being able to operate digital modes would be required today. For contesting, a single antenna with which you sacrifice gain for bandwidth is useful. If the antenna is too sharp, pointing the antenna becomes problematic. Loop yagi antennas can be fabricated easily from aluminum strips that you can get sheered at a local metal fab shop. I still have a stack of these in a drawer somewhere. Regarding amplifiers, I like WIK, have pairs of 3cx100A amps that are large, bulky, and require a HV power supply. Today's solid state amps are the way to go if you haven't yet made these investments. I'd like to fab an amp using one of the russian tubes like the GI-7B, which is supposed to operate at these frequencies and put out a few hundred watts - just to see how well it might work. ARRL published a few books on microwave a while back that had designs for transverters, amps, and antennas. They were very useful as well as articles from the various VHF conferences. If you like building and experimenting, these are great bands to play around - especially if you have a friend or group to work with.
     
  6. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I built my dual 3CX100A5 amp for 23cm back in 1979, before hardly anyone had an SS amp more than a few Watts for that band.

    Today, that's sure changed and I'd rather use transistors and microstrip on good dielectric material. FR4 material isn't good at that frequency, but other stuff is.

    My tooob amp for 23cm uses only 1000V B+ and the power supply is in a separate enclosure the same size as the RF/cavity deck (quite small, uses something that looks like an old TV set transformer); that went together in an hour or two. Best part at the time is the tubes were readily available surplus for $10 each, sometimes less and if one failed, to replace it took a few minutes. They just "plug in." Even the anode connection was made by just a ring of spring finger contacts, so the tube literally just plugs in.:)
     
  7. KA2BPP

    KA2BPP Premium Subscriber QRZ Page

    Ash,

    check out http://w1ghz.org/
    lots of good reading and stuff to build
     
    KK4YWN likes this.
  8. KK4YWN

    KK4YWN Ham Member QRZ Page

    Thanks for the book reference. I found used copies of the mi rowave experimentors hand book and the satelite experimentors handbook. Both shiped for $20.
     
  9. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    If you're going to homebrew antennas, go for loop yagis.

    They detune less with rain than other designs at that frequency, and they're easy to build.
     
    KK4YWN likes this.
  10. W0AAT

    W0AAT XML Subscriber QRZ Page

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