On Wed, Aug 15, 2018 at 01:41 AM, Henning Weddig wrote:
The magic frequency is over 60 mhz. At 58.1125 the half IF is ~29.06mhz
or the point where the 2IF minus LO will be one loud birdie (RX and TX).
It moves the current issue up but not out. Works for cell but not a 3-30mhz radio.
Band pass filters are easier. As is we are asking a 300mhz transistor to work
marginally at 45mhz. Going up makes that worse. Better yet a better transistor.
Makes the core a module and replaceable with improved or different technology
without having to toss everything else out with it.
FM again, why? For 10M, easier to make a dedicated radio for that with
a decent limiter for the RX. Same for AM, 10W radio with full carrier AM
is 2.5W, not a power house. It forces a decent power amp as well one
that an sustain full power. Better to limit to SSB/CW. Switched filters
Input highpass at 1.6mhz? Correct?
This is an approach the driver has to be designed with 50 ohm outputs. The interconnect can be short wires.
Goes without saying easy and its more about layout and switching.
Should be there and its a very useful and simple thing.
Leave out the gps locked oscillator. we are not designing the next generation Hilberling. More than one LO device
makes a lot of sense and allows for a better RF layout to put it where its needed. The 5351 is inexpensive.
No, as much as I use them and like them they are not cheap and for those that
are mechanically challenged or lack dexterity the word torture comes to mind.
They are not inexpensive Cables with the connector on them are not cheap.
The base idea that RF should be routed with RF connectors is a vhf and up
thing. With care at HF pin connectors can work but the board layout has to
not create RF current loops.