Re: [Elecraft] SP3 A/B Switch Problem (IK4EWX)

[Geert Jan de Groot]

  I had the same problem about one years ago. I have two SP3 loudspeakers, on
on each receiver or both speakers, ore one receiver with the K3S audio
effects that use both loudspeakers.
The switch scratched when changing channel and it attenuated the audio
signals.


Keep in mind that the SP3 speaker switches only switch speaker signal.
You Cannot Switch A Small-signal With A Switch.
Switches need a little DC (1mA probably sufficient) to "burn clean" the 
contacts.


I suspect that a 10K resistor from the speaker output to +12V will cause 
the desired 1mA to do the cleaning.
Looking at the schematics, this isn't easy because R1 and R63 on the 
K3IO board are in the way. So, you need to add a bipolar capacitor in 
series, and resistors to +12V to make it happen. Don't be surprised if 
operating the switch will "click" a bit but 1mA is well within safe 
limits for the speaker.


If you don't want to do through this, disconnect the K3, connect the 
same 10K resistor and operate the switch a few times.


Elecraft isn't the only to make this design mistake - I have some Yaesu 
speakers that did suffer the same problem and that were remedied the 
same way.


Since the K4 comes with a SP4 speaker that looks similar - I wonder if 
this design issue was addressed for the K4?


73,

Geert Jan PE1HZG

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com 

Re: [Elecraft] SP3 A/B Switch Problem

[IK4EWX]

 I had the same problem about one years ago. I have two SP3 loudspeakers, on
on each receiver or both speakers, ore one receiver with the K3S audio
effects that use both loudspeakers.
The switch scratched when changing channel and it attenuated the audio
signals. 
The italian service obtained from Elecraft USA the switch with the connected
cable and we had to change it.
The real problem seemed a part failure, but we had changed it after only
little more than two years of use.
I would like mil parts and radio with mil parts, but a Rhode Schwartz or a
Cubic cost too much...
Ian IK4EWX





--
Sent from: http://elecraft.365791.n2.nabble.com/
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com 

[Elecraft] SP3 A/B Switch Problem

[Ferris Jennings]

My SP3 A/B switch has an issue. I use the supplied speaker cable from my K3S
to the speaker A jack. I listen with the switch in the A position, but
frequently push it in to the B position as a convenient mute. Switching back
to A to listen, the sound is somewhat muted scratchy; cutting in and out as
I wiggled the switch. I push the switch in and out a few times, and it
returns to normal. I've switched the cable to the B port, but it's the same
issue.

 

I removed the side panel, thinking I could shoot a bit of DeoxIT into the
switch, but it appears that the switch is sealed, so I canned that idea.

 

Any suggestions on an easy fix or should I order up a new switch from
Elecraft and replace it?

 

Thanks in advance

Ferris Jennings NB6T -

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com 

Re: [Elecraft] Sp3 a/b switch

[ab2tc]

Hi,

Why would the amplifier be damaged from driving an open circuit?
Transformerless solid state audio amplifiers typically are perfectly happy
driving an open circuit.

AB2TC - Knut


Don Wilhelm wrote
> Richard,
> 
> If your K3 has all the audio amplifier mods installed, there should be 
> no problem.  If you have an early K3 without those mods, you could 
> damage the speaker audio amplifier by driving it into an open or shorted 
> load.  Yes, the A/B switch will make the load to the K3 an open circuit 
> when switched to the non-K3 position.
> 





--
View this message in context: 
http://elecraft.365791.n2.nabble.com/Sp3-a-b-switch-tp7627095p7627100.html
Sent from the Elecraft mailing list archive at Nabble.com.
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] Sp3 a/b switch

[Don Wilhelm]

Richard,

If your K3 has all the audio amplifier mods installed, there should be 
no problem.  If you have an early K3 without those mods, you could 
damage the speaker audio amplifier by driving it into an open or shorted 
load.  Yes, the A/B switch will make the load to the K3 an open circuit 
when switched to the non-K3 position.


See the listing of K3 mods to determine whether your K3 has the mods 
installed when you bought it or if they should be added.


Adding the mods is not difficult and can prevent a trip to Elecraft for 
your K3 should the audio amp fail.


73,
Don W3FPR

On 2/18/2017 10:32 AM, Richard Donner wrote:

Hi
I was wondering if there is a problem using the A/B switch   on the SP3
as a  on / off   switch for audio from the k3.  The k3 would be on.
It seems like this would be ok but I am checking with the experts here.

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] Sp3 a/b switch

[Harry Yingst via Elecraft]

Doing so would mean outputting the K3 into an open load
I would at a minimum turn down the volume on the K3

  From: Richard Donner <richarddn...@gmail.com>
 To: "Elecraft@mailman.qth.net" <elecraft@mailman.qth.net> 
 Sent: Saturday, February 18, 2017 10:32 AM
 Subject: [Elecraft] Sp3 a/b switch
   
Hi
    I was wondering if there is a problem using the A/B switch  on the SP3
as a  on / off  switch for audio from the k3.  The k3 would be on.
It seems like this would be ok but I am checking with the experts here.
Thanks Richard
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to hlyin...@yahoo.com


   
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

[Elecraft] Sp3 a/b switch

[Richard Donner]

Hi
I was wondering if there is a problem using the A/B switch   on the SP3
as a  on / off   switch for audio from the k3.  The k3 would be on.
It seems like this would be ok but I am checking with the experts here.
Thanks Richard
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

[Elecraft] SP3 A/B

[Dauer, Edward]

Very nice; thanks.  I will probably get in line to order one.  But a
question - what tricks can the A/B switch on the front do?  In particular
- if I have one SP3, the K3 menu configuration set to spkr 1, a headset in
the front headset socket of the K3 listening to stereo using the sub RX on
split, and I push the A/B, can it be programmed to turn on the speaker
mono?  And then, with just another press, turn the speaker off and return
me to headset split / stereo?

Tnx,

Ted, KN1CBR


>Date: Mon, 14 Sep 2015 18:13:21 -0700
>From: Wayne Burdick 
>To: elecraft...@yahoogroups.com
>Cc: Elecraft Reflector 
>Subject: Re: [Elecraft] Elecraft SP3 External Speaker details [Updated
>   photos]
>Message-ID: 
>Content-Type: text/plain;  charset=us-ascii
>
>Here are two much better photos of the SP3:
>
>   http://www.elecraft.com/K3/sp3_2a.jpg
>   http://www.elecraft.com/K3/sp3_1a.jpg
>
>73,
>Wayne
>N6KR
>

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com