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K3 Keyout?

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Jim AB3CV

K3 Keyout?

I don't have schematics for my K3S but going by those for the K3. The
KeyOut line (RCA Jack) is driven by a IRF1630 which appears to be out of
production. Either than or it is a misprint and is actually a IRF630.

If the latter it appears pretty burly. Can I assume it can drive a pair of
reed relays without suffering an inductive kick failure?

73

jim ab3cv
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Guy Olinger K2AV

Re: K3 Keyout?

From page 17 in the manual:

KEY OUT (RCA/Phono) is the amplifier T-R relay
keying output, capable of keying up to +200VDC
@ 5A.

You might call that "burly". With the K3 one can key the "relay" jacks of
some old amplifiers (e.g. SB220/221) that would fry the circuit in other
transceivers. Just don't try it on a Collins 30L1, which is a high
*negative* voltage.

73, Guy K2AV

On Mon, Sep 7, 2015 at 7:59 PM, Jim Miller <[hidden email]> wrote:

> I don't have schematics for my K3S but going by those for the K3. The
> KeyOut line (RCA Jack) is driven by a IRF1630 which appears to be out of
> production. Either than or it is a misprint and is actually a IRF630.
>
> If the latter it appears pretty burly. Can I assume it can drive a pair of
> reed relays without suffering an inductive kick failure?
>
> 73
>
> jim ab3cv
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>

Don Wilhelm-4

Re: K3 Keyout?

In reply to this post by Jim AB3CV

Why do you need to look at the schematic. The K3S specification says it
will handle +200 volts at 5 Amps, so those are the limits at the box level.
No matter what the device data sheet for a device might indicate, there
can be other considerations in the K3S design (or other 'boxes') that
say you should observe the specifications for the entire unit rather
than trying to re-engineer from the device specifications.

73,
Don W3FPR

On 9/7/2015 7:59 PM, Jim Miller wrote:
> I don't have schematics for my K3S but going by those for the K3. The
> KeyOut line (RCA Jack) is driven by a IRF1630 which appears to be out of
> production. Either than or it is a misprint and is actually a IRF630.
>
> If the latter it appears pretty burly. Can I assume it can drive a pair of
> reed relays without suffering an inductive kick failure?
>
>

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Jim AB3CV

Re: K3 Keyout?

Thanks all. The 200v tolerance will handle the minimal energy produced by
the reed relay field collapsing.

73

jim ab3cv

On Mon, Sep 7, 2015 at 8:32 PM, Don Wilhelm <[hidden email]> wrote:

> Why do you need to look at the schematic. The K3S specification says it
> will handle +200 volts at 5 Amps, so those are the limits at the box level.
> No matter what the device data sheet for a device might indicate, there
> can be other considerations in the K3S design (or other 'boxes') that say
> you should observe the specifications for the entire unit rather than
> trying to re-engineer from the device specifications.
>
> 73,
> Don W3FPR
>
>
> On 9/7/2015 7:59 PM, Jim Miller wrote:
>
>> I don't have schematics for my K3S but going by those for the K3. The
>> KeyOut line (RCA Jack) is driven by a IRF1630 which appears to be out of
>> production. Either than or it is a misprint and is actually a IRF630.
>>
>> If the latter it appears pretty burly. Can I assume it can drive a pair of
>> reed relays without suffering an inductive kick failure?
>>
>>
>>
>

Jack Brindle-2

Re: K3 Keyout?

If it were _my_ K3 (or K3S), I would add the very inexpensive 1N5400 or 1N5407 diode across the relays and eliminate the worry. Even reed relays can produce quite a kick, and the low cost of the diode would do wonders for peace of mind.

This same advice goes for antenna (and other) relays switched by the KRC2.

Jack Brindle, W6FB

> On Sep 7, 2015, at 5:40 PM, Jim Miller <[hidden email]> wrote:
>
> Thanks all. The 200v tolerance will handle the minimal energy produced by
> the reed relay field collapsing.
>
> 73
>
> jim ab3cv
>
>
>
> On Mon, Sep 7, 2015 at 8:32 PM, Don Wilhelm <[hidden email]> wrote:
>
>> Why do you need to look at the schematic. The K3S specification says it
>> will handle +200 volts at 5 Amps, so those are the limits at the box level.
>> No matter what the device data sheet for a device might indicate, there
>> can be other considerations in the K3S design (or other 'boxes') that say
>> you should observe the specifications for the entire unit rather than
>> trying to re-engineer from the device specifications.
>>
>> 73,
>> Don W3FPR
>>
>>
>> On 9/7/2015 7:59 PM, Jim Miller wrote:
>>
>>> I don't have schematics for my K3S but going by those for the K3. The
>>> KeyOut line (RCA Jack) is driven by a IRF1630 which appears to be out of
>>> production. Either than or it is a misprint and is actually a IRF630.
>>>
>>> If the latter it appears pretty burly. Can I assume it can drive a pair of
>>> reed relays without suffering an inductive kick failure?
>>>
>>>
>>>
>>
> ______________________________________________________________
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>
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Fred Townsend-2

Re: K3 Keyout?

Jack:
A diode is a good idea and sound engineering practice. However if you look
at the FET schematic from the manufacture's data sheet carefully you will
see that the FET has a built in diode. That's why they make such good relay
drivers.
73
Fred, AE6QL

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Jack
Brindle
Sent: Monday, September 7, 2015 7:49 PM
To: Jim Miller
Cc: Elecraft Reflector
Subject: Re: [Elecraft] K3 Keyout?

If it were _my_ K3 (or K3S), I would add the very inexpensive 1N5400 or
1N5407 diode across the relays and eliminate the worry. Even reed relays can
produce quite a kick, and the low cost of the diode would do wonders for
peace of mind.

This same advice goes for antenna (and other) relays switched by the KRC2.

Jack Brindle, W6FB

> On Sep 7, 2015, at 5:40 PM, Jim Miller <[hidden email]> wrote:
>
> Thanks all. The 200v tolerance will handle the minimal energy produced
> by the reed relay field collapsing.
>
> 73
>
> jim ab3cv
>
>
>
> On Mon, Sep 7, 2015 at 8:32 PM, Don Wilhelm <[hidden email]> wrote:
>
>> Why do you need to look at the schematic. The K3S specification says
>> it will handle +200 volts at 5 Amps, so those are the limits at the box

level.
>> No matter what the device data sheet for a device might indicate,
>> there can be other considerations in the K3S design (or other
>> 'boxes') that say you should observe the specifications for the
>> entire unit rather than trying to re-engineer from the device
specifications.

>>
>> 73,
>> Don W3FPR
>>
>>
>> On 9/7/2015 7:59 PM, Jim Miller wrote:
>>
>>> I don't have schematics for my K3S but going by those for the K3.
>>> The KeyOut line (RCA Jack) is driven by a IRF1630 which appears to
>>> be out of production. Either than or it is a misprint and is actually a

IRF630.

>>>
>>> If the latter it appears pretty burly. Can I assume it can drive a
>>> pair of reed relays without suffering an inductive kick failure?
>>>
>>>
>>>
>>
> ______________________________________________________________
> Elecraft mailing list
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> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html Message delivered to
> [hidden email]

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Chris Hallinan

Re: K3 Keyout?

Along the same lines, does anyone have a recommendation for a good reed
relay to use? I want the 2 Qs: Quiet and Quick. ;)

73,
Chris K1AY

On Mon, Sep 7, 2015 at 11:34 PM, Fred Townsend <[hidden email]>
wrote:

> Jack:
> A diode is a good idea and sound engineering practice. However if you look
> at the FET schematic from the manufacture's data sheet carefully you will
> see that the FET has a built in diode. That's why they make such good
> relay
> drivers.
> 73
> Fred, AE6QL
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of Jack
> Brindle
> Sent: Monday, September 7, 2015 7:49 PM
> To: Jim Miller
> Cc: Elecraft Reflector
> Subject: Re: [Elecraft] K3 Keyout?
>
> If it were _my_ K3 (or K3S), I would add the very inexpensive 1N5400 or
> 1N5407 diode across the relays and eliminate the worry. Even reed relays
> can
> produce quite a kick, and the low cost of the diode would do wonders for
> peace of mind.
>
> This same advice goes for antenna (and other) relays switched by the KRC2.
>
> Jack Brindle, W6FB
>
>
> > On Sep 7, 2015, at 5:40 PM, Jim Miller <[hidden email]> wrote:
> >
> > Thanks all. The 200v tolerance will handle the minimal energy produced
> > by the reed relay field collapsing.
> >
> > 73
> >
> > jim ab3cv
> >
> >
> >
> > On Mon, Sep 7, 2015 at 8:32 PM, Don Wilhelm <[hidden email]>
> wrote:
> >
> >> Why do you need to look at the schematic. The K3S specification says
> >> it will handle +200 volts at 5 Amps, so those are the limits at the box
> level.
> >> No matter what the device data sheet for a device might indicate,
> >> there can be other considerations in the K3S design (or other
> >> 'boxes') that say you should observe the specifications for the
> >> entire unit rather than trying to re-engineer from the device
> specifications.
> >>
> >> 73,
> >> Don W3FPR
> >>
> >>
> >> On 9/7/2015 7:59 PM, Jim Miller wrote:
> >>
> >>> I don't have schematics for my K3S but going by those for the K3.
> >>> The KeyOut line (RCA Jack) is driven by a IRF1630 which appears to
> >>> be out of production. Either than or it is a misprint and is actually a
> IRF630.
> >>>
> >>> If the latter it appears pretty burly. Can I assume it can drive a
> >>> pair of reed relays without suffering an inductive kick failure?
> >>>
> >>>
> >>>
> >>
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net Please help support this email
> > list: http://www.qsl.net/donate.html Message delivered to
> > [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
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> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message
> delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
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>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

--
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