KDSP2 auxbus won't synchronize

[eurom6]

Sirs,  I hope one of you can help.  I have assembled the KDSP2 and  
have been using it for 2 mos.  Occasionally I'd have to "restart" my  
K2 when it couldn't find the DSP (lost synchronization)  to re-
establish proper function.  I now can no longer get the K2 to syn  
with the KDSP2.  I have done what Elecraft has recommended,  
specifically, gone over assembly, checked for seated ICs,  resoldered  
every connection, and still no diff.  The DSP filters come on but no  
access to adjust them and on cw the freq is way too high rendering it  
useless.  Why does the manual say "let us know if this happens  
frequently"?  tnx,  I enjoy reading the reflector daily.  73  John  
N0GBR
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[KK7P]

John Moore wrote:
> Sirs,  I hope one of you can help.  I have assembled the KDSP2 and have
> been using it for 2 mos.  Occasionally I'd have to "restart" my K2 when
> it couldn't find the DSP (lost synchronization)  to re-establish proper
> function...

What is the serial number of your K2?

73,

Lyle KK7P

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[KK7P]

John Moore wrote:
> Lyle, #02260,  it has the newest firmware,

It may be an issue with the auxbus loading.  A KAT100 can also affect
things since it loads the auxbus, too.

In any event, at s/n 3000 the following components were changed on the
auxbus:

Control board

R6 was 470 ohms now 100 ohms
C12 was 1,000 pF now 2,700 pF

RF Board

R64 was 470 ohms now 100 ohms

***

I suggest you change R6 on the Control board from 470ohms to 100 ohms.

Others who have reported similar difficulties have found this cleared
things up for them.

73,

Lyle KK7P



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[Don Wilhelm-3]

John,

I really don't know why that 'notify us ...' statement is still in the
KDSP2 manual I believe it should have been removed after a short time of
experience with the KDSP2.  Perhaps Lyle Johnson can shed some light on it

An intermittent of any nature is usually caused by a bad solder
connection.  How hot was your soldering iron when you did the soldering?
  If it was less than 700 degrees F, you may not have heated the solder
pads sufficiently and you have a bad solder connection but don't know
it.  Turn your soldering station up to 750 degrees F and reflow the
board adding a bit of extra flux if any connections look suspicious.  If
you do not know what to look for when evaluating the soldering, look at
the soldering document in the Builder's Resource page of the Elecraft
website - there are several illustrations that may be helpful.

73,
Don W3FPR

John Moore wrote:

> Sirs,  I hope one of you can help.  I have assembled the KDSP2 and have
> been using it for 2 mos.  Occasionally I'd have to "restart" my K2 when
> it couldn't find the DSP (lost synchronization)  to re-establish proper
> function.  I now can no longer get the K2 to syn with the KDSP2.  I have
> done what Elecraft has recommended, specifically, gone over assembly,
> checked for seated ICs,  resoldered every connection, and still no
> diff.  The DSP filters come on but no access to adjust them and on cw
> the freq is way too high rendering it useless.  Why does the manual say
> "let us know if this happens frequently"?  tnx,  I enjoy reading the
> reflector daily.  73  John  N0GBR

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