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1296 transverter options?

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by K3RW, Aug 18, 2017.

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  1. K3RW

    K3RW Premium Subscriber QRZ Page

    Looking at DEMI, I get the impression they don't have a 1296 transverter. Looks like lots of amps and LNAs but not actual transverter I could find.

    I thought I read somewhere they were redesigning it. Hmm.

    I see Kuhne has one ($$$) and I saw another one somewhere else a while ago. It looks like SSB USA doesn't currently make one. Minikits out of Australia has some transverters but it looks like a beast to assemble it, and doesn't look like its a complete kit without a lot of work. I'm not feeling that confident!

    Hmm. I see transverters on Ebay around $100 (1.25m, and I'm thinking of getting one) but nothing for 1296.

    Am I missing a good source?

    I have a IC-7600 (and some other ICOMs) and it has a transverter mode, but not seen any online info about that. Not really sure what that does or if it works well. Just curious if you'd used that feature.

    I'm probably going to pick up one of the Ukranian transverters for 1.25m later this year.
     
  2. N8XQM

    N8XQM Premium Subscriber QRZ Page

    K3RW likes this.
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

  4. KK4YWN

    KK4YWN Ham Member QRZ Page

    Ssssshhhhhh! I already spent my allowance!
     
  5. K3RW

    K3RW Premium Subscriber QRZ Page

    I saw that one, but no price on their website. But hey--that's more like it--budgetwise I mean. I can't seem to tell from their page if it is a kit or not.
     
  6. K3RW

    K3RW Premium Subscriber QRZ Page

    It looks great but seems to be a bit of a budget-buster for me.

    But I'm a bit lost on the transverters and such. Some of these DEMI ones say 'no T/R switch' and I'm not sure what that means to me. My plan is to use them SSB. If I just wanted to get on a repeater I'd probably buy a cheap HT.

    I get the impression that what makes a transverter cheap or expensive is the output/the noise factor/or some other thing, and a combination of these factors. Not sure what the substantive difference is between some of these, but I can compare $120 to $1200 and wonder.
     
  7. W0AAT

    W0AAT XML Subscriber QRZ Page

    I have one of the SG labs transverters. Haven't got it on the air yet(need to get an antenna up for the Sept VHF contest). Well built little unit. I am building an RA18H1213G amplifier to boost it to 20+ watts(that will eventually drive the 300 watt amp). W6PQL sells the circuit board for the small amp and the 150 watt amp modules I am paralleling.

    $22.50 assembled http://w6pql.com/1296/index.htm

    About 1/3 of the way down http://w6pql.com/parts_i_can_provide.htm
     
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  8. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    "No T/R switch" means you'd need an external coaxial relay to use one. For those who already own a compatible relay that actually works at 1.2 GHz, this can save them some money.

    Cost differences may be driven partly by how much profit the seller needs or wants to make, but I think "mostly" by performance parameters -- and a BIG performance parameter is power output at 1.2 GHz, where power does not come cheaply. A 1W transverter might make contacts, but a 10-20W transverter will make a lot more. Solid state amplifiers for 1.2 GHz are expensive to build, even if you homebrew one.

    My 1.2 GHz amplifier isn't solid state, it uses a pair of 3CX100A5s (2C39s, really) in a cavity and runs about 100W PEP output power; the "parts" for that only cost about $200 total but the labor was the big part...took probably three or four 8-hour days machining parts and assembling it all. If I charged myself even $50 an hour (pretty cheap labor) that would be over $1000 in labor!:p But it works, and has 10 dB power gain, so 10W drive yields 100W output.
     
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  9. W0AAT

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    Now you can get 150 watts out cheap, $450, add a cabinet, power supply, cooling fan, relay(s) and good to go.

    Many run split transmit and receive on 1296 so only 1 relay needed at the tower top. A mast mounted preamp on 1296 is a must for weak signals due to coax losses and running separate feed lines cuts the need for 2 relays down to 1. Or still 2 if you use a preamp protect relay that isolates the input to a 50 ohm dummy load during TX. That is how I plan on setting up my 1296 antenna. I can run LMR400 on receive and use hardline for transmit.
     
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  10. W1VT

    W1VT Ham Member QRZ Page

    The hard part of a 1296 transverter is the bandpass filters. Microstrip filters work OK at low power, but at high power you want something that can be cheaply and easily shielded. Helical filters are great if you can buy them as assembled and tested units. A non-starter if you need to build them yourself at 1296 MHz. Interdigital filters work really at this frequency well if don't mind a metal machine shop project.

    Zack W1VT
     
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