[linrad] VHF: mixer question.

[wb9uwa@xxxxxxxxxxx]

I am working on the local oscillator of my home brew Linrad receiver.
I have a crystal controlled source of 116.505 Mhz at +24 dbm.
I also have a PLL source of 25.045 Mhz at +24 dbm.
I would like to mix these two together to provide the needed 141.550 Mhz 
local oscillator so I can use a 2.5 Mhz IF for 144.050 Mhz RX.
I plan to drive a pair of TUF-1H mixers. I need two for Xpol operation.
Each TUF-1H requires +17dbm of LO drive. I plan to use a 5 pole helical
filter (2db loss) after the mixer and each TUF-1H should be driven, I think with a 
3 db pad to control impedance. Since each mixer will share power, I lose 3db more.
 This means I need an output of +25dbm at 141.550 Mhz. That's a quarter of a watt!

I think I can find in my junk box, some VHF transisters that will handle the power 
and frequency. I am hoping to combine a pair of them in either series or parallel to
have a power mixer with two inputs. Does anyone have a clever, but simple favorite
circuit to do this?

I am using parts on hand, where possible. The +25dbm comes from the exciter
boards of LOW Band and  VHF Motorola Micors.

73, Jim Shaffer, WB9UWA.


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