SDR evolution

[K1JJ]

Good score! Did you get the Gemini and Saturn boards?

They were out of stock. But I'm in good company - they name their boards and I name my rigs.  I might approach them about developing an SDR Plexiglas enclosure named "Fabio". What ya think?

T

[Steve - K4HX]

Just make sure you get the one with the Taylor hybrid option. Otherwise, they don't work worth crap.

BTW, the Saturn board will melt four feet of snow in two minutes.

[WA1GFZ]

Glad you joined the gang Tom.
It has been very interesting lurking with really smart guys.
You quickly learn why we have two ears but one mouth

[K1JJ]

I keep getting private emails from these guys offering more ideas and help just from those two posts I made.  They know how to treat a Newbie, I'll say that.

BTW, a VK said he has 100w SS amps available -  "We use a local amplifier here which is from a Codan Flying Doctor Radio.  0.5 watt in for 100 watts out.  I can source one for you very cheaply if you want."   He says they are -50db 3rd and remotely controlled by the HPSDR for bandchanging.


Another German mentioned that if two linears of the same IMD are put in cascade, they will be 6db IMD worse at the output. I always thought it would be more like ~one db worse???    6db seems a bit much considering the multi-stage chains of SS amps used today.

T


T

[WA1GFZ]

I still prefer the erb on a big heatsink. You can't beat medical equipment for good design. The amps had digitally controlled bias so it was switched on just before a pulse is sent through to control heat. That is the reason they get away with a small heatsink. I bypassed all the digital stuff in your amp.
I sawed it off my amp and duplicated the bias circuit on that little piggy back board in my set up.