[Kenwood] Question about DSP connections on TS-450/690

[Rob Atkinson]

get a service manual so you can figure out the product detector and find out
where it is in the rig.   drill a hole in the back panel and install an RCA
phono jack.  run a shielded unbalanced two conductor audio cable from the
jack over to the p.d. area.  ground the shield at the jack collar and on the
pc ground on the p.d. board (this may solve your pin one problem if you have
that issue).  put a cap in series with the audio cable center, try 0.1 uF to
begin with.  because the rig is solid state the cap can be 25 or 50 v.
 with an audio amp on, driving a speaker (you'll need one that has a preamp
in it) and connected to the rear panel jack, probe around with the other end
of the cap until you find the best pickoff for the p.d. audio and tack
solder it on.   You'll be amazed at how good it will sound with all the
stock base band audio circuitry in the rig bypassed.   If you use some sort
of wide passband filter it will sound even better.
Try picking up an old push pull vacuum tube amp--you can find these mono
p.p. little 12 watt 6BQ5 amps on eBay or at hamfest flea markets and they
will drive a big 3 way speaker cabinet  with no problem.  All you usually
need to do is recap them--pull out the electrolytics and plastic paper caps
and replace them with new lytics and Vishay poly-films.  Back in the 1950s
heathkit sold a bunch of them, models EA-2 and EA-3; they have 12AX7
preamps, ideal for product detector audio and you get this warm tubey boat
anchor sound out of your solid state Kbox.  If this DSP2 thing Cliff
mentioned is direct from the p.d. (I don't know what the low pass filter
does) then you may not even need to drill any holes.   Or, there may be some
unused by you connector you can hijack for this purpose.

73

rob
K5UJ


On Sun, Oct 31, 2010 at 4:24 PM, Michael G. Carper <mike at wa9pie.net> wrote:

> I've been looking at the DSP-100 Service Manual.  It shows the connection
> from the transceiver's DSP3 as:
>
> Pin 1   Audio input
> Pin 2   GND
> Pin 3   Audio output
> Pin 4   GND
> Pin 5   DSP connect signal
> Pin 6   FSK keyer
> Pin 7   CW keying signal
> Pin 8   GND
> Pin 9   Reference signal (10kHz or 10MHz)
> Pin 10  GND
> Pin 11  Mic input
> Pin 12  Mic GND
> Pin 13  Transmission control
>
> Then it shows DSP2 as Receive IF; DSP1 as Transmit IF.
>
> Assuming that the pin 1 reference for the DSP3 connection is from the
> perspective of the DSP-100, I'm inclined to believe that this is audio
> output from the transceiver.  Seem reasonable?  (I'm looking for the TS-690
> service manual to see if it's shown there.)
>
> Mike, WA9PIE
>
> -----Original Message-----
> From: Clif [mailto:avvidclif at wildblue.net] On Behalf Of Clif Holland
> Sent: Sunday, October 31, 2010 12:31 PM
> To: Michael G. Carper; kenwood at Mailman.qth.net
> Subject: Re: [Kenwood] Question about DSP connections on TS-450/690
>
> Have you looked at the service manual?
>
> DSP2 comes off the product detector and thru a LPF and out.
>
> Clif Holland KA5IPF
> www.avvid.com
>
>
>
>
> ----- Original Message -----
> From: "Michael G. Carper" <mike at wa9pie.net>
> To: "'Clif Holland'" <clif at avvid.com>; <kenwood at Mailman.qth.net>
> Sent: Sunday, October 31, 2010 8:45 AM
> Subject: RE: [Kenwood] Question about DSP connections on TS-450/690
>
>
> > Yep, I've been all over the p22 scenario.
> >
> > Page 22 identifies the external speaker jack (which is amplified) and the
> > ACC2 connections (which include an unamplified audio out).  However, my
> > ACC2
> > jack is occupied by my MicroKEYER II (and I wish it had an unamplified
> > audio
> > out).  [When I say 'unamplified', I'm really referring to line-level
> audio
> > output.  The audio amplifier used in most of these radios has a rather
> > high
> > S/D ratio.  So I don't want to amplify the distortion of the signal.  I'd
> > rather get a line-level signal that I can amplify with a very clean audio
> > amplifier into some very clean speakers.]
> >
> > I've gotta believe that there's a line-level audio signal at one of these
> > DSP connectors.
> >
> > Mike, WA9PIE
> >
> > -----Original Message-----
> > From: Clif [mailto:avvidclif at wildblue.net] On Behalf Of Clif Holland
> > Sent: Sunday, October 31, 2010 1:45 AM
> > To: Michael G. Carper; kenwood at Mailman.qth.net
> > Subject: Re: [Kenwood] Question about DSP connections on TS-450/690
> >
> > Read PG 22 of the owners manual.
> >
> > Clif Holland KA5IPF
> > www.avvid.com
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "Michael G. Carper" <mike at wa9pie.net>
> > To: <kenwood at Mailman.qth.net>
> > Sent: Saturday, October 30, 2010 11:29 PM
> > Subject: [Kenwood] Question about DSP connections on TS-450/690
> >
> >
> >>I don't use these DSP connections on the back of my TS-690 because I
> don't
> >> have the DSP-100.  However.
> >>
> >>
> >>
> >> If any of these connections provide an unamplified audio signal, I'm
> very
> >> interested in connecting it to a very clean (studio quality) audio
> >> amplifier
> >> and speakers.  (I'm getting a bit tired of listening to the audio
> through
> >> a
> >> $2 speaker in a $73 Kenwood case.)
> >>
> >>
> >>
> >> Does anyone have the pin-out diagrams for DSP1, DSP2, and DSP3?
> >>
> >>
> >>
> >> Mike, WA9PIE
> >>
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>
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