Anyone ever convert a 2 meter all mode (SSB) to work on 222 MHz?

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by K3SK, Oct 31, 2019.

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  1. WA4ILH

    WA4ILH Subscriber QRZ Page

    I seem to recall back in the early 70s, a guy in Norfolk, VA had converted an old GE pre-progress line to 220 MHz FM. This was an old tube type FM rig but, if I remember correctly after nearly 50 years, he said he would never do that again. Even with a grid dip meter and a cheap spectrum scope (not a full- fledged spectrum analyzer) it was just too difficult.
    Tom WA4ILH
     
  2. W1VT

    W1VT Ham Member QRZ Page

    There is more to life than making money. I've been busy working on my rose garden. There are lots of things that can be done in the middle of winter while the roses are dormant. I was out yesterday working on the roses. :)
     
    N3AWS likes this.
  3. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    For FM on the old 220 MHz segment, the Motorola Sensicon "A" high band receiver and the Motorola "G" high band transmitters (the one used in the T43GGV units with the 2E26 doubler / driver and 6146 final) could be modified in 30-minutes or less!

    The receiver is the version with the loaded cavities in the "front end" / mixer stages. You just stuffed aluminum foil into the movable portion of the cavities compressing it as much as possible. When that assembly was full of aluminum foil, the front end would tune to 220 MHz and the crystal oscillator multiplier would tune to times-7 instead of times-5. With the proper crystal, the receiver still met the original high band specifications.

    The transmitter required even less effort: You shorted out 1-turn of the doubler / driver plate coil and shorted out 1-turn of the final amplifier plate coil. This changed the driver from a doubler to a tripler and got the final resonant on 220 MHz. Then, you replaced the 6146 final amplifier tube with a 2E26 because the 6146 was "flaky" on 220 MHz. This dropped the power output from 25-watts to between 10-watts and 15-watts.

    This is what we did in the Dallas / Fort Worth area to get on 220 MHz including for the first FM repeater on that band. I am not sure, but, the remains of this repeater may still be in the attic over my garage!

    Glen, K9STH

     
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Six days from now a million roses will be marching down Colorado Boulevard in Pasadena.

    They prepare all year for this!
     
    N3AWS likes this.
  5. AD5HR

    AD5HR Ham Member QRZ Page


    "Send me dead flowers"?
     
  6. KM3F

    KM3F Ham Member QRZ Page

    For the cost of a Down East Microwave Transverter and a 10 meter all mode mobile radio, you can be on 222 with a lot less cost and hassle.
    Then spend the time and investment on an amplifier and a good beam.
    .
    This is the way I went using a Kenwood TS 2000 that can already receive the band FM on the second receiver.
    The Kenwood can store repeaters in memory and work any mode.
    The Transverter drives a SS amplifier at up to 190 watts on FM.
    The amplifier is a British design for a compandored data system that never 'flew' and found for near give=away cost with matching power supply because no wants them or knows how to use them.
    Here in my area, I hunted for repeaters according to a data base and was able to bring up 18 repeaters.
    It's a shame this band has little use except on contest week ends and home brewed station equipment such as I have done.
    Only a few repeaters have any action now and then.
    There are HTs' that have the band such as the Kenwood TH-F6 and some that offer the band in different band combinations/models.
     

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