1.25 Meter Amps

Discussion in 'Amateur Radio Amplifiers' started by K7JCN, Jul 12, 2014.

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  1. WB3BEL

    WB3BEL Ham Member QRZ Page

    There is always TE systems for these kind of amps. They are not cheap but they are several steps above a Mirage in quality.

    http://www.tesystems.com/

    As far as the old FAA amps go. Some folks are still using them but as another poster indicated the converted Larcan TV transmitter power amps are a smarter buy unless you can get the old FAA amp for a bargain. Old FAA amps seem to be ~$250-350. They make 300-350W and are pretty heavy and loud. The Larcan will make 700-900W cost about $600-700 and run off a 50V server switching power supply.
     
  2. WA7KKP

    WA7KKP Ham Member QRZ Page

    You won't find many (if any) other commercial amplifiers built for ham use, because . . . only in North America is 220 a ham band. Same reason that "ham" gear isn't that available. What made 10/6/2/440 popular is that there was a LOT of surplus FM gear out there that dcould be easily modified to ham use.

    If you do some homework, you might be able to find some MIL surplus equipment that might work. The Pentagon uses 225-400 MHz a lot; often the mil surplus gear will tune down to 222 without hassles.

    Gary WA7KKP
     
  3. K7JCN

    K7JCN Ham Member QRZ Page

    Fair enough. I know it's not a well used band even here in the states, which is part of the appeal to me. I think if a good product came out from ICOM or Yaesu even, to make a VHF transceiver 1.25/2/6 mobile rig, I bet it would get a bit more use. Not knocking Alinco as they have a decent little mobile, but it's not an ICOM, Kenwood or Yaesu. And it's a monoband to boot. I tried 6 meter FM for my simplex but it's just a noisy ol' band especially in town. I have to have the squelch almost fully clockwise to stop it and sometimes that doesn't even work. So far I'm hopeful that 1.25 will do better. So far so good, just need a little more power and working on a little more height.
     
  4. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    KKP:

    Actually, the 1.25-meter band is available in all of Region II (North and South America), not just North America.

    However, the activity on the band is very "spotty" in both North and South America.

    Glen, K9STH
     
  5. N2GZ

    N2GZ Platinum Subscriber Platinum Subscriber QRZ Page

    You are off by a factor of Pi on your area calculations. Area(Circle) = Pi*r^2, not A=(Pi*r)^2. Probably an issue with order of operations when operating the calculator, easy mistake.

    Coverage areas for 25mi radius and 40mi radius should be 1963mi^2 and 5027mi^2 respectively.



    Here is a nifty utility for mapping line of sight coverage:
    http://www.heywhatsthat.com/
    Click on New Panorama and input your location and height above ground.
     
  6. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Yep, I agree. Was using the calculator built into the computer and didn't enter the data in the correct sequence! Thanks for catching that.

    Still, "big difference" (almost 3:1) either way, obviously. And it really happens. 10-15-20' additional height for a VHF omni can easily achieve such a difference, and people can hardly believe it until they make the change and witness it for themselves.
     
  7. K7JCN

    K7JCN Ham Member QRZ Page

    I have noticed it with my other antennas, definitely gets better higher up and when I was first licensed I was astounded at the difference 15 feet made. On my 1.25 antenna I was testing it out at 15 feet. Now it's at 25 feet at the base of the antenna and it did improve quite a bit. I'm hoping for another 15 feet but we'll see if I can make a plain old TV mast be sturdy being that long (5 and 10 foot sections).Here's hoping!
     
  8. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Why use 1-1/4" TV mast, when 2" tubing is four times stronger and doesn't cost any more?:confused:
     
  9. K7JCN

    K7JCN Ham Member QRZ Page

    I can't find 2" tubing that is crimped on the ends to fit together. I've been through Lowe's and Home Depot and a few local plumbing shops. Not finding them. I would rather do it that way. I also don't have tools to customize anything. Kinda like watching those youtube videos of a guy making an "Easy antenna" so "Lets go to the machine shop..." I don't have one of those...LOL.
     
  10. W0AAT

    W0AAT XML Subscriber QRZ Page

    Most any muffler shop can swage tubing either up or down.
     
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