Re: switching a heath amp

Posted by Joe Subich, W4TV-4 on Mar 15, 2012; 6:36pm
URL: http://elecraft.85.s1.nabble.com/switching-a-heath-amp-tp7376348p7376619.html


> If that voltage is for certain positive, the answer is yes, the K3
> will switch it, but if it is negative, connect your other relay.

The problem is that many "high voltage" amplifiers have significant
relay current and no current limiting or reverse EMF ('catch") diode
and often exhibit a large *negative* spike when the relay opens.

An external relay or a "buffer" like Ampkeyer, Ameritron ARB-704,
WB9KZY "Keyall", etc. is a good insurance policy.  A relay or buffer
is required with any negative voltage (SB-200, FL-2100, FL-2100B, etc.)
key lines.

73,

    ... Joe, W4TV


On 3/15/2012 2:07 PM, Don Wilhelm wrote:

> Bob,
>
> If that voltage is for certain positive, the answer is yes, the K3 will
> switch it, but if it is negative, connect your other relay.
>
> 73,
> Don W3FPR
>
> On 3/15/2012 1:12 PM, [hidden email] wrote:
>> Gang
>>
>> the heath series of amps use bial voltage to switch the thing from T/R
>> and That amounts to 130 +- volts
>> would the K3 be Ok switching this or should I look to add an additional
>> relay
>> and switch that
>>
>> Bob K3DJC
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