[Elecraft] K3 and AMP

[Joe Subich, W4TV]

 > Maybe. If you get a very old amp you may have difficulties with the
 > keying circuit. More knowledgable people then I am will need to help
 > you with that.

Heath SB-200, SB-220, (and variants), Yaesu FL1200 (and variants),
Drake L4, and Kenwood TS-922 are all issues due to either negative
relay controls, AC relay controls or a high current spike on relay
opening.

The smart thing to do is to measure the relay line on any amp you
might suspect - if the key up voltage is negative, AC or < +24V
you will need a buffer or will need to add a "soft key" circuit to
the amplifier.  Also measure the relay current with the amp keyed
as you will not want to see more than about 100ma to prevent issues
with inductive kick on relay release.

73,

    ... Joe, W4TV


On 10/24/2012 11:13 AM, Gary Smith wrote:
> RC,
>
> Maybe. If you get a very old amp you may have difficulties with the
> keying circuit. More knowledgable people then I am will need to help
> you with that. You'll only know that when you investigate the
> specific amp. Not all older amps are an issue; I have a 30 year old
> Alpha 77SX and run directly from the K3 key out to the Alpha's "Relay
> in" and it works great. (I'd asked here regarding any specific
> interface problems before buying this specific amp)
>
> If you use CW and like QSK, you'll want that to be a factor in your
> amp and get an amp with QSK. If not, it won't much matter except a
> QSK relaying system will always be quieter than the non-QSK versions.
> You might not like a loud click when you transmit or it may not
> bother you in the least, that's your call.
>
> 73,
>
> Gary
> KA1J
>
>> I wish to purchase an Amp either new (or new to me ) to use with my K3/100.
>> Are there any that I should avoid and will I need interfacing circuitry
>> Thanks RC kc5wa
>>
>> --
>> "ETERNAL VIGILANCE" is the price of FREEDOM.....Thomas Jefferson
>> ______________________________________________________________
>> 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
>