5.7Ghz Transverter and 2W for sale - Dual RX for EME

[Mike Lewis]

Surplus to my needs - I have working 10GHz and 5.7Ghz transverters for sale.  Both are around 90mW out.  I also have a 2W amp for 5.7GHz that can be easily added on.  They currently use an FT-817 as the IF rig, which is also for sale separately.  Other IF rigs could be used with a new PTT cable and appropriate drive level adjustments.

 

This email details the 5.7Ghz transverter.  I mention them both here since they currently share a common IF rig.  Asking price is negotiable with the goal to get it into the hands of someone who will use it, and if the FT-187 is part of the sale or not.  I also have a 28dB gain BBQ sectional dish for 5.7. If buyer has a 5.7GHz antenna they prefer, I may keep this one.

The 2 transverters use the same DIN cable to the FT-817 Acc jack for PTT.

5.7GHz Transverter Details

 

   

 

 

This is a unique transverter because it has dual receiver with a common PLL, useful for diversity RX, or a cross polarized antenna for EME.  It is 90mW output with RX and TX tunable bandpass filters.  It has built in OCXO.  IF drive is 430MHz at -8dBm for ~90mW output.

 

On the 5.7 unit, besides PTT, it uses the FT-817 analog band data signal and TxInhibit to lock out TX unless the band (430Mhz) is correct.  Jumpers can disable this feature.   The FT-817 is configured to output a very low “-8dBm” on 430Mhz via the factory cal menu.    I have a spreadsheet of all the FT-817’s cal settings and the changes I made to a few of them on 430MHz to get the power down.  I also have a compact homebrew 2W 5.7Ghz amp module with fan that can be easily plumbed in and some spare parts (transistor, isolator schematic).

 

Fred WA7TZY and I collaborated on this design back in 2005 to convert surplus neighborhood 5Ghz band WiFi units into simplex units for ham use.  3 of these exist today.  I have full schematics and design notes.  We also designed a 41Mhz PLL LO reference (with PCB) that uses an external 3Mhz surplus OCXO.  I have a spare OCXO and some spare parts still.

 

It uses as 16F877 PIC CPU for the PLL programming and sequencing/PTT, PLL lock LED, TX LED, and PTT band interlock  (if enabled) with software I wrote.

 

The RX and TX PCBs are in separate, milled aluminum housings sandwiched together.  On top of this I bult a box from ¼” aluminum and a cover for a rugged compact and portable unit that can take a beating on the road.  After the BPF is a SMA T/R switch.  There is switch power for the optional 2W RF amp with can plumb in with UT-141 before the TR switch.

 

The PLL is in its own compartment. 

  

 

 

More details are in the attached document.

 

 

Mike Lewis, K7MDL

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