Back in March, 2018 I tried building up an amp section using an HP mmic
I have in the junk box. It worked very well on the desktop. Flat from
3Mhz to 30Mhz. No oscillation. I simply could find no way to add it
into the ubitx around Q90 (i.e. before and after) where it didn't break
into oscillation as soon as I tried to transmit.
At this point it would be easier to make up a new PA driver chain on a
replacement circuit board. Mount it on standoffs above the existing
board using coax in from Q90 and coax out to IRF510's. It's not a
project I want to take on. I would rather set the power out to 1w or
2w, have a clean signal, and use an external amplifier.
On Fri, 14 Sep 2018 15:23:49 -0700
"RCBoatGuy via Groups.Io" <ijnfan-HamRadioemail@example.com> wrote:
In response to Warren's question about why the MMIC's would be