[Elecraft] SPE 1K-FA Amp hookup and ALC Question

[Bob McGraw K4TAX]

For the K3S, I suggest reading Fred Cady's book, specifically page 170 
{9.2 Automatic Level Control - ALC} , page 222 {To ALC or Not to ALC}, 
and page 291 {EXT ALC} for particulars.   In summary, Elecraft does not  
advise using ALC from the amp.

Personal opinion, the amp should provide adequate protection for high 
SWR and excessive drive.   It should not rely on other means for 
protection.

73
Bob, K4TAX



On 10/9/2017 6:16 PM, M. George wrote:
> I have an SPE 2K-FA I'm using with a K3S... very happy with it.  I made a
> verbose YouTube <https://www.youtube.com/watch?v=Ku8Gyl0amRY> video early
> on after I received the amp which gets into the details of making the
> interface cable.  (these days guys can pass the Extra Class exam but they
> can't make a simple interface cable to an amplifier... ;) )  All of the
> details would apply to the 1K-FA.
>
> As others have stated, don't use ALC on the K3 to control the output of
> your SPE amp, however it is viable as a safety measure to let the amp drop
> the K3 output if it's software deems necessary. (despite what you will read
> in the SPE manual where it says just crank the power output on your exciter
> all the way up and let the amp control the output via ALC)  I get into the
> details around this in the video several times.  You can fast forward and
> find the areas you are interested in related to the cable interface to the
> K3.
>
> Here is the link to the video again... I hope you find something helpful...
> related to your 1K-FA.
>
> https://www.youtube.com/watch?v=Ku8Gyl0amRY
>
> Max NG7M
>
>
>
>
>
> On Mon, Oct 9, 2017 at 4:05 PM, Bob McGraw K4TAX <rmcgraw at blomand.net>
> wrote:
>
>> I agree with Jim, K9YC on the ALC points.
>>
>> With older radios, namely tube types which required the exciter PA to be
>> loaded correctly to be linear, this power level would overdrive many
>> amplifiers.   Hence ALC from the amp to the transceiver/transmitter was
>> required to control the drive power.
>>
>> Today's radios have much more accurate power control methods. These
>> methods are far superior to those found in most amps.   Most solid state
>> amps have adequate protection with regard to overdrive, again ALC from the
>> amp to the radio is not needed. And as Jim indicated, if one chooses to use
>> ALC from the amp to the transceiver and it is not properly adjusted, one
>> can expect signal report issues and unfriendly neighbors on the radio
>> spectrum.
>>
>> 73
>>
>> Bob, K4TAX
>>
>>
>> On 10/9/2017 4:50 PM, Jim Brown wrote:
>>
>>> On 10/9/2017 12:48 PM, Clay Autery wrote:
>>>
>>>> I'm being given an SPE 1K-FA for use with my fully current K3s.
>>>>
>>>> I'm being told that the K3s and SPE don't play well together using "ALC".
>>>> A conflicting report is telling me that Elecraft addressed the ALC issue.
>>>>
>>> I owned one of these amps for a few months, having bought it to get more
>>> power on 6M than the KPA500 did.  I didn't like it much. You probably know
>>> that ALC should NEVER be used between a rig and an amp to set the output
>>> power. That's a recipe for creating harmonics, clicks, and splatter. The
>>> right way to do it is to reduce drive power. If you're going to use ALC at
>>> all, set output power by reducing drive and use ALC ONLY to protect the amp
>>> when something goes wrong with an antenna (like the operator connecting the
>>> wrong one). :)
>>>
>>> 73. Jim K9YC
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>>
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