(K3) with FL2100B amp

[Tom Boucher]

Chuck,

I don't think you're right - the K3 'Key Out' is spec'd 200V @ 5A. The FL2100 'RY' relay control switches 12V @ 200mA only.

73
Tom G3OLB

AE4CW wrote:
>However, you will need an interface to key the amp from the K3 as the amp
>keying voltage is not compatible with the K3.  I used a simple 12V reed
>relay powered from the K3 12V RCA jack.

______________________________________________________________
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

[Iain MacDonnell - N6ML-2]

The issue with these older amps is that the keying voltage is
negative, which doesn't work with the solid-state output in the K3.

>From practical experience, a FL2100B will NOT work when connected
directly to the K3 - you need an interface of some sort.

    ~Iain / N6ML


On Thu, Aug 19, 2010 at 6:18 PM, Tom Boucher <[hidden email]> wrote:

> Chuck,
>
> I don't think you're right - the K3 'Key Out' is spec'd 200V @ 5A. The FL2100 'RY' relay control switches 12V @ 200mA only.
>
> 73
> Tom G3OLB
>
> AE4CW wrote:
>>However, you will need an interface to key the amp from the K3 as the amp
>>keying voltage is not compatible with the K3.  I used a simple 12V reed
>>relay powered from the K3 12V RCA jack.
>
> ______________________________________________________________
> 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
>

______________________________________________________________
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

[W8JI]

Check the actual amp you are using, old is not enough to know voltage and
polarity on the relay line. :-)

The FL2100 and 2100B are negative low voltage.

The FL2100Z is positive low voltage with a huge current spike.

http://www.w8ji.com/fl2100_problems.htm

73 Tom

______________________________________________________________
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

[Joe Subich, W4TV-4]

 > The FL2100 'RY' relay control switches 12V @ 200mA only.

Use a voltmeter to check the keying line on your FL-2100
or FL-2100B.  The manuals for both of those amplifiers show
a relay keying voltage between -13V and -18V.  The relay
voltage is derived from a 13V transformer winding through
a half-wave rectifier (series diode) and 1000 uF capacitor.
the -16V (+/-) under load is used for both grid bias and
relay power.

Note, if the amplifier was ever modified to use Svetlana 572B
tubes, the half-wave rectifier may have been replaced by a
voltage doubler and the open circuit relay voltage would be
-35V!

In either case, the FL-2100/2100B will not work directly with
the K3 "Key Out" signal.

73,

    ... Joe, W4TV


On 8/19/2010 2:18 PM, Tom Boucher wrote:

> Chuck,
>
> I don't think you're right - the K3 'Key Out' is spec'd 200V @ 5A. The FL2100 'RY' relay control switches 12V @ 200mA only.
>
> 73
> Tom G3OLB
>
> AE4CW wrote:
>> However, you will need an interface to key the amp from the K3 as the amp
>> keying voltage is not compatible with the K3.  I used a simple 12V reed
>> relay powered from the K3 12V RCA jack.
>
> ______________________________________________________________
> 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
>

______________________________________________________________
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

[Tom Boucher]

I stand corrected - hadn't realised the 'Z' was different.

73 Tom G3OLB

----- Original Message -----
From: "Tom W8JI" <[hidden email]>

> The FL2100 and 2100B are negative low voltage.
>
> The FL2100Z is positive low voltage with a huge current spike.
>

______________________________________________________________
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