[Elecraft] [K3] Tune Up of ALS-600

[Joe Subich, W4TV]

> Rather than mess with adjusting the drive and/or connecting 
> up ALC, I place a relay-switched 2dB attenuator in-line with 
> the amplifier.  The attenuator automatically goes in-line 
> when I turn on the amplifier so I can just leave my K3 set 
> for 100 watts all the time.  The attenuator is inexpensive 
> and easy to make, and works great.  

Instead of an external attenuator which can degrade receive 
performance, particularly on six and 10 meters under current 
conditions, one would be better advised to build an attenuator 
into the amplifier.  Such an attenuator could be put on the 
amplifier side of the T/R relay so it was automatically bypassed 
when the amplifier is turned, in stand-by, or in receive. 

In addition, a less complex/less expensive L-pad may be used  
inside the amplifier.  

73, 

   ... Joe, W4TV 
 


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Phil & 
> Debbie Salas
> Sent: Friday, July 24, 2009 7:20 AM
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] [K3] Tune Up of ALS-600
> 
> 
> When you set the ALC on CW, this also sets the ALC for your 
> peak SSB power. 
> And you're right - you should adjust the ALC so it just comes 
> on with the 
> drive necessary to get your desired output.
> 
> That being said, I don't use ALC.  My ALS-600 needs about 65 
> watts to drive 
> it to full output.  Rather than mess with adjusting the drive and/or 
> connecting up ALC, I place a relay-switched 2dB attenuator 
> in-line with the 
> amplifier.  The attenuator automatically goes in-line when I 
> turn on the 
> amplifier so I can just leave my K3 set for 100 watts all the 
> time.  The 
> attenuator is inexpensive and easy to make, and works great.  
> Any full power 
> transmit spikes related to a transceiver's ALC not acting 
> fast enough on the 
> first dit or speech peak will obviously not be there as the 
> transceiver 
> output is already at full power.  This attenuator is described in the 
> "Articles" section of my website at ww.ad5x.com.
> 
> Phil - AD5X 
> 
> ______________________________________________________________
> 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