[Heath] Fw: SB-102 S-Meter operation

[Robert Gibbons]

Hi, Joe. It's been a while. Looking over the circuit I would check the
values of R104, R105, and R115. That appears to control the value you would
get for a meter reading. If they are all in spec, but the meter is still
low, playing around with the values should adjust the meter reading to what
you expect it to be. I think just changing the value of R115 would do the
trick.

Bob Gibbons
WB3CPZ

On Mon, Mar 27, 2017, 1:54 PM Joseph Smalley via Heath <
heath at puck.nether.net> wrote:

>
>
> On Sunday, March 26, 2017 10:54 PM, Joseph Smalley <
> mymodecw-hamitup at yahoo.com> wrote:
>
>
>
>  Hello to the group.  I still use my SB-102 that I built in 1972,  I have
> two issues I want to fix.
>
> Number ONE is the poor operation of the S-meter very rarely does the
> S-meter give a good reading
>
> even on real strong signals.  A fellow ham close by gets a pinned needle
> on my TS-530sp on the
>
> Sb-102 it will be S9. Most stations I work have a loud signal but low
> reading on the S-meter. Never S9
>
> I have put new 6AU6 I.F. amplifier tubes in the radio no help.  Replaced
> the Product detector/AVC tube, no help
>
> Any ideas will be appreciated.
>
> Number TWO sometimes the resting (idling) plate current will increase
> above the set value of 50 MA, this happens
>
> when I get long winded CW only here.
>
> I recently repaired a SB-100 for a friend that had an excessive plate
> current reading which turned out to be
>
> the cathode resistors on the final amplifiers.This is not what I am
> experiencing.  The reading was  3 ohms for the
>
> six 20 OHM resistors in parallel, when I replaced the resistors  the
> reading went to 1.6 OHMS which I measured
>
> on another properly working SB-102.
>
> Any info will be appreciated.
>
> 73 Joe WA3CKA
>
>
>
>  Hello to the group.  I still use my SB-102 that I built in 1972,  I have
> two issues I want to fix.
>
> Number ONE is the poor operation of the S-meter very rarely does the
> S-meter give a good reading
>
> even on real strong signals.  A fellow ham close by gets a pinned needle
> on my TS-530sp on the
>
> Sb-102 it will be S9. Most stations I work have a loud signal but low
> reading on the S-meter. Never S9
>
> I have put new 6AU6 I.F. amplifier tubes in the radio no help.  Replaced
> the Product detector/AVC tube, no help
>
> Any ideas will be appreciated.
>
> Number TWO sometimes the resting (idling) plate current will increase
> above the set value of 50 MA, this happens
>
> when I get long winded CW only here.
>
> I recently repaired a SB-100 for a friend that had an excessive plate
> current reading which turned out to be
>
> the cathode resistors on the final amplifiers.This is not what I am
> experiencing.  The reading was  3 ohms for the
>
> six 20 OHM resistors in parallel, when I replaced the resistors  the
> reading went to 1.6 OHMS which I measured
>
> on another properly working SB-102.
>
> Any info will be appreciated.
>
> 73 Joe WA3CKA
>
>
>
>
> _______________________________________________
> Heath mailing list
> Heath at puck.nether.net
> https://puck.nether.net/mailman/listinfo/heath
>
-- 

Robert Gibbons
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