>
>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?
>
It is already the cleanest radio ever built. .
>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.
ALC is never fast enough.
>The mics I have tried are Shure 444 (desk)
>and 404c (mobile) and they both do the same thing.
An electret mic. makes cleaner audio.
>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.
>
less ALC means less feculence.
>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.
>
With 5kHz signal spacing, there is nothing better.
happy new year, Jim
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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