[AMPS] 6146 splatter help?

[J. Bradshaw]

Since this is where the experts are--

Is there any way to improve the splatter on my TS830s (low s/n) with RCA 6146B's?

On voice peaks (p's, t's and ch's) there are burps like key click sup and down the band about -40-60 db from the intended energy.
It is only barley noticeable up and down with a 10+ S9 signal in another rcvr (although I hear the same thing coming from my TS130
too).

It is clean from the 12BY7 on a spectrum analyzer (FM/AM 1100s).  It seems that maybe the alc just isn't fast enough whenever the
grid starts pulling current.  The  mics I have tried are Shure 444 (desk) and 404c (mobile) and they both do the same thing.  The
mic gain is critical and goes from 0 to full slam scale around 9 o'clock but less so with the processor on (15 db)  about 10 or 11
o'clock.

The plate is 750v, the grid is -60v and the SG is 235.  I dropped the SG down to another tap at 210v,  but there was no difference
in operation other than Ip went from 210ma to 180ma.  Idles at 60ma.  I tried opening the grid chokes on the resistors, (47 ohm) and
tried a standby pair of GE 6146A's but no change at all.  The 9.00v and 3.60v are set after doing the power supply mods, and the
vbt/carrier oscilllators have been adjusted for max bandwidth (+- 1.4 kHz @ -6 db) in ssb (Thanks Rich. The Fcenter on the 455k5 was
a wee off).   Most voltages on Q19,Q20 look good, but I can't probe the alc line without messing it all up.

So is there a problem with the alc or pa or am I chasing ghosts?  I love this radio better than some of my newer ones.

Jim, ac6tk


--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com