A problem has developed when using the FT-817 with my Tokyo-Hy-Power 50 Watt
HL-50B brick amplifier.
In the CW mode there is a sizable time delay, like ten seconds or more,
before a full sensitivity receive condition returns after a dit or dah has
been sent. Sometimes it will recover faster by helping it along a bit by
sending an extra dit or so. The CW delay is set to 10 ms also. You hear the
rig return to receive, but there is a noticeable receive desensitization
period of a least 10 seconds. THE RIG DOES NOT DO THIS BAREFOOT - - ONLY WITH
THE HL-50B 50 WATT AMPLIFIER ON ! THIS BRICK AMPLIFIER SITS RIGHT NEXT TO
THE FT-817 AT THE OPERATING POSITION [MAYBE 2 INCHES AWAY] !
Suspecting this is an RFI problem, I added toroids to the DC input and to the
CW keying line of the FT-817, and a toroid to DC input of the HL-50B
amplifier. I unplugged the external speaker line and am listening through the
FT-817 internal speaker. The antenna is a Force 12 Yagi about 20 feet above
the rig, on the roof of the house. The FT-817 and the ATU are grounded to a
cold water pipe. The HL-50B brick amplifier is presently not directly
grounded, but is grounded through the ATU.[there is no grounding lug on the
HL-50B amplifier]
I am convinced that because the FT-817 works perfectly in the barefoot mode,
that there is indeed a self induced RFI related problem, set up by me.
Any thoughts out there!
73,
Norm Wesler K2YEW
K2YEW@...
