[Elecraft] K3 Receive Attenuation with KPA500 in Operate
Ron D'Eau Claire
ron at cobi.biz
Thu Aug 1 23:00:21 EDT 2013
Actually the KPA500 amplifier is designed to have its PTT line "hot
switched" at full power. See page "Key Line Hot Switching" on page 14 of the
manual. The 29 watt limit was set as default to keep people from blowing up
other less robust amplifiers by switching the PTT line at full power.
When using the KPA500 with the KAT500, in the Utility Program click
"Optimize for KPA500" to adjust the settings to take full advantage of the
capabilities of the K-line equipment (see Amplifier Key Interrupt Power on
page 29 of the KAT500 Owner's Manual).
73 Ron AC7AC
-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Cady, Fred
Sent: Thursday, August 01, 2013 7:29 PM
To: 'bwruble at gmail.com'
Cc: 'Elecraft Reflector'
Subject: Re: [Elecraft] K3 Receive Attenuation with KPA500 in Operate
Pin 10, in the K3 ACC is the Key Out line that goes first to the KAT500 in
the KPAK3AUX cable and then on to the KPA in the second DB15 cable. When the
KAT institutes a tune cycle, it opens that line so it is interrupted from
going onto the KPA. Thus the amp won't be keyed and putting out power when
the KAT is tuning. The Amplifier key Interrupt power configuration in the
KAT is there because in some amplifiers (somebody may be using the KAT with
a brand X amp) you cannot interrupt the amp's keying line at more than a
certain power output without damaging the amp. So the KAT is delivered with
that interrupt power set at 29 watts (I think). If the power coming into the
KAT is more than that when the KAT wants to tune, it won't open the keying
line to save damaging the amp but that, of course, could damage the KAT. So,
because the KPA can be operating at full power out and won't suffer any
damage by opening its keying line, you should configure the KAT as Ian says
to optimize i t for the KPA500.
Cheers,
Fred KE7X
Fred Cady
fcady at ieee dot org
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net [mailto:elecraft-
> bounces at mailman.qth.net] On Behalf Of Brian F. Wruble
> Sent: Thursday, August 01, 2013 8:13 PM
> To: iain macdonnell - N6ML
> Cc: Elecraft Reflector
> Subject: Re: [Elecraft] K3 Receive Attenuation with KPA500 in Operate
>
> Got it. Thanks.
>
> Figure 1 in the KAT500 manual leads one to believe that both cables
> need to be KPAK3AUX, as both DB15 cables in the diagram are labeled
> "3", and one of the cables has the warning not to use a standard VGA
> cable. The note, "3"
> also suggests 2 of that particular Elecraft cable. An obvious
> conclusion
> --- though wrong --- is that both need to be the same, and both could
> be the special Elecraft (KPAK3AUX) cable or a modified VGA cable to be
> the same as the KPAK3AUX..
>
> My understanding on the tuner issue was that the KAT500 could be
> damaged by going through a retune cycle at high power. Thus, some
> kind of safety lockout is needed to prevent that. If I can configure
> the KAT500 to tune when the KPA500 is in "operate" mode, how do I
> prevent that kind of damage from occurring?
>
> Brian
>
>
>
> *Brian F. Wruble, C.F.A.
>
> *70 is the new 40.*
> *
> Mail: 1107 Key Plaza, PMB 447 Key West, FL 33040-4077
> Summers: P.O.Box 57, 7400 Augustine Herman Highway, Georgetown, MD
> 21930
> eFax 305.768.0278
>
>
>
>
>
>
>
> On Thu, Aug 1, 2013 at 10:00 PM, iain macdonnell - N6ML
> <ar at dseven.org>wrote:
>
> > Brian was referring to his "cable lineup" (quoted below).
> >
> > Brian, you do need two HD15 cables.... The point that Fred was
> > making is that one of them needs to be the Elecraft KPAK3AUX, whilst
> > the other one could be a straight-through cable with all 15 pins
> > connected. The KPAK3AUX does not connect all 15 pins, and that's
> > important. There is no harm in using two KPAK3AUX's, and that is
> > actually the safest configuration (cables designed for VGA monitor
> use
> > will not necessarily work).
> >
> > The KAT500 should tune when the KPA500 is in operate mode, though -
> > there is a specific configuration for that in the KAT500 Utility. On
> > the "Configuration" tab, click "Edit Configuration...", then in the
> > "Amplifier Key Interrupt Power" tab , click "Optimize for Elecraft
> > KPA500".
> >
> > 73,
> >
> > ~iain / N6ML
> >
> >
> >
> > On Thu, Aug 1, 2013 at 6:48 PM, Ron D'Eau Claire <ron at cobi.biz>
> wrote:
> > > Where do you see two DB15 cables in a diagram Brian?
> > >
> > > Ron AC7AC
> > >
> > > -----Original Message-----
> > > From: elecraft-bounces at mailman.qth.net
> > > [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Brian F.
> Wruble
> > > Sent: Thursday, August 01, 2013 4:57 PM
> > > To: Cady, Fred
> > > Cc: Elecraft Reflector
> > > Subject: Re: [Elecraft] K3 Receive Attenuation with KPA500 in
> Operate
> > >
> > > F
> > > red, thanks. I am using that cable both places where my diagram
> says
> > "DB15
> > > Cable".
> > >
> > > I guess I needed to have invested in only one.
> > >
> > > Everything seems to work, and the tuner protection works as well.
> I
> > proved
> > > that by lowering K3 output power to 5 watts (just to be safe),
> allowing
> > the
> > > KPA500 to key and asking the KAT500 to re-tune. it refuses to do
> so.
> > That
> > > is the right result.
> > >
> > > 73,
> > >
> > > Brian
> > >
> > >
> > >
> > > *Brian F. Wruble, C.F.A.
> > >
> > > *70 is the new 40.*
> > > *
> > > Mail: 1107 Key Plaza, PMB 447 Key West, FL 33040-4077
> > > Summers: P.O.Box 57, 7400 Augustine Herman Highway, Georgetown, MD
> 21930
> > > eFax 305.768.0278
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > On Thu, Aug 1, 2013 at 7:08 PM, Cady, Fred <fcady at ece.montana.edu>
> > wrote:
> > >
> > >> Hi Brian,
> > >> Make sure you are using a KPAK3AUX cable somewhere between the K3
> and
> > >> the KPA500. It can be between the K3 and the KAT or the KAT and
> the
> > >> KPA. You can use a full DE15HD cable other places but the
> KPAK3AUX
> > >> cable needs to be in there somewhere.
> > >> Cheers,
> > >> Fred KE7X
> > >> "The Elecraft K3: Design, Configuration and Operation"
> > >> "The Elecraft KX3 - Going for the Summit"
> > >> (soon - "The Elecraft K-Line - KPA500 and KAT500")
> > >>
> > >>
> > >> -----Original Message-----
> > >> From: elecraft-bounces at mailman.qth.net [mailto:
> > >> elecraft-bounces at mailman.qth.net] On Behalf Of Brian F. Wruble
> > >> Sent: Thursday, August 01, 2013 4:17 PM
> > >> To: don at w3fpr.com
> > >> Cc: Elecraft Reflector
> > >> Subject: Re: [Elecraft] K3 Receive Attenuation with KPA500 in
> Operate
> > >>
> > >> Hi Don,
> > >>
> > >> Thanks for the prompt response.
> > >>
> > >> Yes, I am using the DB15 and the PTT line. I got it working.
> Here is
> > >> my new cable lineup:
> > >>
> > >>
> > >>
> > >>
> > >> 1. ACC on K3 (DB15) >>> DB15 Y Cable | >>>DB15 Cable >>> "XCVR"
> > >> (DB15) On
> > >> KAT500
> > >>
> |
> > >> And |
> >>>
> > "ACC"
> > >> on Navigator Interface
> > >>
> > >>
> > >> 2. "RS232" on K3 >>> "XCVR" (RS232) on P3
> > >>
> > >>
> > >> 3. "PC" on P3 >>> "RS232" on Navigator Interface
> > >>
> > >>
> > >> 4. "AMP" on KAT500 (DB15) >>> DB15 Cable >>> "AUX1" (DB15) on
> KPA500
> > >>
> > >> 5. NO PTT LINE into KPA500 or into KAT500
> > >>
> > >> 6. No "Key Line Interupter" anyplace.
> > >>
> > >>
> > >> With this lineup, is the KAT500 protected from the KPA500 keying
> when
> > >> the
> > >> KAT500 is tuning?
> > >>
> > >> I must admit, I have mightily confused myself in this process.
> > >>
> > >> Thanks again,
> > >>
> > >> Brian W3BW
> > >>
> > >>
> > >>
> > >> *Brian F. Wruble, C.F.A.
> > >>
> > >> *70 is the new 40.*
> > >> *
> > >> Mail: 1107 Key Plaza, PMB 447 Key West, FL 33040-4077
> > >> Summers: P.O.Box 57, 7400 Augustine Herman Highway, Georgetown,
> > >> MD
> > >> 21930 eFax 305.768.0278
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> On Thu, Aug 1, 2013 at 5:01 PM, Don Wilhelm
> > >> <w3fpr at embarqmail.com>
> > wrote:
> > >>
> > >> > Brian,
> > >> >
> > >> > I have heard this before, and as I recall it has to do with the
> DB15
> > >> > cable and the PTT cable when used together.
> > >> >
> > >> > Are you using the PTT cable in addition to the cable from the
> > >> > K3
> ACC
> > >> > cable? If so, pin 10 of the cable should not be included. See
> the
> > >> > note on page 8 of the KAT500 manual.
> > >> >
> > >> > Normally you would not have to use the PTT cable with the K3.
> See
> > >> > pages 3 and 4 of the KAT500 manual. For this arrangement, piin
> 10
> > >> > of the ACC cable must be present.
> > >> >
> > >> > If you have other devices that need access ti the K3 Key Out
> line,
> > >> > you would use the PTT cable AND use the key line interrupter to
> > >> > disconnect pin 10 from the DB15 Interface cable without the
> > >> > need
> for
> > >> > removing pin
> > >> 10. .
> > >> >
> > >> > 73,
> > >> > Don W3FPR
> > >> >
> > >> >
> > >> > On 8/1/2013 4:30 PM, Brian F. Wruble wrote:
> > >> >
> > >> >> Hi all:
> > >> >>
> > >> >> I am running a newly assembled "K-Line" --- K3/100, KPA500 and
> > KAT500.
> > >> >> The
> > >> >> K3 is pretty "loaded" with KRX3, KAT3, KXV3A, etc.
> > >> >>
> > >> >> I just noticed that received signals are down 4 S-units when
> the
> > >> >> KPA500 is in Operate. In Standby, signals pop right up.
> > >> >>
> > >> >> Reading past reflector emails on the topic, I found one thread
> that
> > >> >> suggested this may have to do with the state of the KPA500 PTT.
> I
> > >> >> found that pulling the PTT RCA plug out ended the problem.
> > >> >>
> > >> >> Then I replaced the PTT plug, and still had no problem.
> However,
> > >> >> once I actually transmitted, and the PTT acted to key the
> KPA500,
> > >> >> the problem recurred >>> Low sigs when the amp is in Operate,
> Full
> > >> >> sigs when in Standby.
> > >> >>
> > >> >>
> > >> >>
> > >> >
> > >> ______________________________________________________________
> > >> Elecraft mailing list
> > >> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > >> Help: http://mailman.qth.net/mmfaq.htm
> > >> Post: mailto:Elecraft at mailman.qth.net
> > >>
> > >> This list hosted by: http://www.qsl.net Please help support this
> email
> > >> list: http://www.qsl.net/donate.html
> > >>
> > > ______________________________________________________________
> > > Elecraft mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > > Help: http://mailman.qth.net/mmfaq.htm
> > > Post: mailto:Elecraft at mailman.qth.net
> > >
> > > This list hosted by: http://www.qsl.net Please help support this
> > > email list: http://www.qsl.net/donate.html
> > >
> > > ______________________________________________________________
> > > Elecraft mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > > Help: http://mailman.qth.net/mmfaq.htm
> > > Post: mailto:Elecraft at mailman.qth.net
> > >
> > > This list hosted by: http://www.qsl.net Please help support this
> > > email list: http://www.qsl.net/donate.html
> >
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
More information about the Elecraft
mailing list