Many thanks for all the replies. I'm still digesting most of it but
there were some common threads (low drive due to exciter foldback).
First, to answer some questions;
- The FT-847 can deliver 50 watts on 2 meters which may be a little low
for full output but I expect to see more than 300w for 50w drive.
- Idle plate current seems to be about 40mA.
- Plate tank is tuning for resonance near the middle of its range.
- *** Grid is tuning on a dip (for low SWR) but not low enough. ***
My observation;
I stuck an SWR meter between the radio and amp and found that I couldn't
tune the SWR below about 2:1 so the FT-847 is folding back.
Tomorrow I'll remove the bottom cover of the cavity and attempt to
better tune the input circuit. Hopefully the drive power will increase
and I'll see more output power.
Thanks again.
Hugh VA3TO
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|