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[K2] KBT2 Battery charger/power supply recommendation?

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Dick Dievendorff

[K2] KBT2 Battery charger/power supply recommendation?

I have a 10-watt K2 with the KBT2 installed. The KBT2 manual recommends a
14.0V power supply or battery life will be "reduced". It's easy to put my
K2 on my station's 12V supply (which is really about 13.6V), but I seek a
small switching power supply that I can adjust to 14V to power my K2 in the
field and keep the internal battery topped off. I have a Gamma Research
HPS-1A which is ideally sized, but I can't adjust the output voltage (and
the filter caps are operating very, very close to their rated voltage).

I thought of a Ramsey Kits LABC1 with a 20V wall wart, but I suspect it
would be electrically too noisy to consider. I could charge the battery with
it, but not while operating any radio in the near vicinity.

So I need a 14V DC 2A battery charger that's electrically quiet. Are there
such things?

73 de Dick, K6KR

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Stephen Prior

Re: [K2] KBT2 Battery charger/power supply recommendation?

Dick

It may be more than you are looking for as you will not need the current it
is capable of supplying, but it's the SEC1223 from Samlex. 23A capability,
as quiet as a mouse rf wise, you will never hear a fan come on and it is
small and extremely well made. A quick tweak of one preset inside will give
you 14.2 volts which is just about right. Perfectly safely and without
stressing anything. I use it to run my K2 and external KPA100. They are
less than 100 ukp over here so should be cheap as anything on your side!

73 Stephen G4SJP

On 17/11/07 18:45, "Dick Dievendorff" <[hidden email]> wrote:

> I have a 10-watt K2 with the KBT2 installed. The KBT2 manual recommends a
> 14.0V power supply or battery life will be "reduced". It's easy to put my
> K2 on my station's 12V supply (which is really about 13.6V), but I seek a
> small switching power supply that I can adjust to 14V to power my K2 in the
> field and keep the internal battery topped off. I have a Gamma Research
> HPS-1A which is ideally sized, but I can't adjust the output voltage (and
> the filter caps are operating very, very close to their rated voltage).
>
>
>
> I thought of a Ramsey Kits LABC1 with a 20V wall wart, but I suspect it
> would be electrically too noisy to consider. I could charge the battery with
> it, but not while operating any radio in the near vicinity.
>
>
>
> So I need a 14V DC 2A battery charger that's electrically quiet. Are there
> such things?
>
>
>
> 73 de Dick, K6KR
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

Leigh L. Klotz Jr WA5ZNU

Re: [K2] KBT2 Battery charger/power supply recommendation?

Administrator

Or do the fused jack mod and use a 3-level charger such as a Battery
Tender Jr insyead of a 14v float.
73,
Leigh/WA5ZNU
Dick, K6KR
> I have a 10-watt K2 with the KBT2 installed. The KBT2 manual
> recommends a
> 14.0V power supply or battery life will be "reduced". It's easy to
> put my
> K2 on my station's 12V supply (which is really about 13.6V), but I
> seek a
> small switching power supply that I can adjust to 14V to power my K2
> in the
> field and keep the internal battery topped off.
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Don Wilhelm-4

Re: [K2] KBT2 Battery charger/power supply recommendation?

In reply to this post by Dick Dievendorff

Dick,

As an alternative, you can make a direct connection to the battery (put
a fuse in for safety please) and use one of the SmartChargers to keep
the battery topped off. Take a look at my website article at
http://w3fpr.qrpradio.com to see how I did it.

73,
Don W3FPR

Dick Dievendorff wrote:
> I have a 10-watt K2 with the KBT2 installed. The KBT2 manual recommends a
> 14.0V power supply or battery life will be "reduced". It's easy to put my
> K2 on my station's 12V supply (which is really about 13.6V), but I seek a
> small switching power supply that I can adjust to 14V to power my K2 in the
> field and keep the internal battery topped off. I have a Gamma Research
> HPS-1A which is ideally sized, but I can't adjust the output voltage (and
> the filter caps are operating very, very close to their rated voltage).
>
>
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Bob Nielsen-2

Re: [K2] KBT2 Battery charger/power supply recommendation?

In reply to this post by Dick Dievendorff

I looked around and couldn't find any small 14.0 volt switchers (I
did find a reference to one but it apparently has been
discontinued). I use a MFJ-4103 with my K2, but it doesn't put out
quite enough voltage to charge the battery. It uses a standard
desktop computer power cord and works fine with 240v input. I use a
small linear supply in the shack and have adjusted the output
accordingly. There are some 15 volt switchers for laptops available
and maybe a series diode or two would do the trick, depending on the
actual output voltage. Most of these are sealed assemblies and not
easy to modify internally.

Bob, N7XY

On Nov 17, 2007, at 10:45 AM, Dick Dievendorff wrote:

> I have a 10-watt K2 with the KBT2 installed. The KBT2 manual
> recommends a
> 14.0V power supply or battery life will be "reduced". It's easy to
> put my
> K2 on my station's 12V supply (which is really about 13.6V), but I
> seek a
> small switching power supply that I can adjust to 14V to power my
> K2 in the
> field and keep the internal battery topped off. I have a Gamma
> Research
> HPS-1A which is ideally sized, but I can't adjust the output
> voltage (and
> the filter caps are operating very, very close to their rated
> voltage).
>
>
>
> I thought of a Ramsey Kits LABC1 with a 20V wall wart, but I
> suspect it
> would be electrically too noisy to consider. I could charge the
> battery with
> it, but not while operating any radio in the near vicinity.
>
>
>
> So I need a 14V DC 2A battery charger that's electrically quiet.
> Are there
> such things?
>
>
>
> 73 de Dick, K6KR
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

Michael Bower N4NMR

List Admin?

Could a list admin please contact me directly? I'm trying to change my
listing but when I ask for my password to be sent it never shows up.

What I want to do is drop this e-mail and sign up with a new one (and in
digest mode).

Thank you.

Michael Bower N4NMR

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Dick Dievendorff

RE: [K2] KBT2 Battery charger/power supply recommendation?

In reply to this post by Bob Nielsen-2

Thanks, Bob.

I'm going to go with the A&A QRP Switchable QRP Smart Battery Charger and
the W3FPR mod to directly connect the battery to the charger.

The A&A is almost the right size, and I get to control the charging current
rate.

73 de Dick, K6KR

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Bob Nielsen
Sent: Saturday, November 17, 2007 1:38 PM
To: Elecraft Support List
Subject: Re: [Elecraft] [K2] KBT2 Battery charger/power supply
recommendation?

I looked around and couldn't find any small 14.0 volt switchers (I
did find a reference to one but it apparently has been
discontinued). I use a MFJ-4103 with my K2, but it doesn't put out
quite enough voltage to charge the battery. It uses a standard
desktop computer power cord and works fine with 240v input. I use a
small linear supply in the shack and have adjusted the output
accordingly. There are some 15 volt switchers for laptops available
and maybe a series diode or two would do the trick, depending on the
actual output voltage. Most of these are sealed assemblies and not
easy to modify internally.

Bob, N7XY

On Nov 17, 2007, at 10:45 AM, Dick Dievendorff wrote:

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