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The 40M Channelized Transceiver has been retrofitted with a Heathkit Crystal Filter!

You will absolutely hate yourself for ignoring my suggestion about buying a Heathkit Crystal Filter on eBay. There are 3 for sale right now for around $15 bucks. Do it and avoid the ruminations of a failure to act.

Yesterday I spent retrofitting the 40M Channelized transceiver with the Heathkit SSB Filter. The code changes took all of 5 minutes and the physical install of removing the Yaesu Filter and installing the Heathkit unit took about 90 minutes total. A good portion of that time was spent designing and milling a new bracket baseplate for the Heathkit and that was done on my manual milling machine.

The matching transformers have a 40:1 ratio achieved with a solenoid winding of 19 Turns tapped at 3 Turns. Those joined at the hip with the TIA topology that 40:1 transform will match 50 Ohms to the 2000 Ohm Zin/out of the Heathkit filter. It is truly a shame that many hams will only try one circuit like the TIA amps and miss out on the chance of experiencing other topologies. Remember mostlydiyrf.com sells a TIA kit and so you have a ready-made source for that bilateral stage amp. 

I also spent some time revamping the Color TFT display to emphasize some info like the frequency readout, by making it larger. We switched around some colors too.



I am pleased with the results. My next retrofit may involve a 3X4 keypad as I know how to take two of the pads and use them for up and down tuning of the RIT. Suddenly, we now are on the brink of an "uptown" rig.

Them that know can make it go!

73's
Pete N6QW

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