[Amps] SG-500 ALC Interface to Kenwood TS-480HX

[Larry Dighera]

Interesting thoughts, gentlemen.  Thank you.

Fortunately, the SG-500 does provide drive attenuation when necessary, so ALC
isn't actually required.  I was just wondering if anyone knew of a circuit that
addressed this issue,  similar to Stefan Stefanov's (AF6SA) excellent KTI-LR
Kenwood Remote LDG Tuner Interface
<http://www.af6sa.com/projects/Kits.html#KTI-LR>.

I appreciate your sharing your knowledge with me, who was only licensed in
2012.

Best regards,
Larry
WB6BBB


On Wed, 27 Jan 2016 17:39:43 -0800, "Jim Thomson" <jim.thom at telus.net> wrote:

>Date: Mon, 25 Jan 2016 18:19:13 -0500
>From: Ron Youvan <ka4inm at gmail.com>
>To: amps <amps at contesting.com>
>Subject: Re: [Amps] SG-500 ALC Interface to Kenwood TS-480HX
>
>    Larry Dighera wrote:
>
>> Given the SG-500's ALC control signal is +1 to +5 VDC, and the Kenwood
>> TS-480HX's ALC signal expects -7VDC, how have others interfaced these two
>> pieces of equipment?
>
>   I don't know, but a 9 Volt battery might do it.
>
>-- 
>   Ron  KA4INM - Youvan's corollary:
>                 Every action results in unwanted side effects.
>
>
>## A  9 vdc battery fed across the far ends of a 50k pot.  Then take the output, between
>wiper and positive end of pot.   Then you can vary the output of the mess  from 0-9 vdc,
>and its all negative Vdc..then  feed that negative 0-9 vdc  into your TS- 480 HX ALC jack.
>Then NO alc connection from xcvr to amp. 
>
>##  Then you can set the  PO of the TS-480HX.....if it has an adjustable PO  to what ever the
>amp requires.   Then dial up the pot till po of the amp just drops a tiny bit.   At that point, you can
>scream all you want..and never over drive the AMP.   You can also turn the PO on the xcvr to max,
>and  tweak the pot for desired drive into the amp. Same deal, scream all u want, and u cant overdrive the amp.
>
>## this  2nd scenario works better, since there is no time lag in developing  ALC  voltage in the xcvr.   You have already
>developed it  via the 9 vdc battery and pot.   The only drawback to using the 9 vdc battery + pot is..... if you whisper into
>mic you will have reduced po from the xcvr.    In normal operation it works superb.
>
>##  an alternate method that may well work is to use a SS  DC to DC  converter.   Then you could  feed the +1  to +5 vdc
>from the amp.... into the input of the DC to DC converter,  the output side will be either 0-5 vdc positive..OR  0-5 vdc
>negative. The dc to dc converter isolates the input to the output side.    In your case, the output side will have its positive
>bonded to chassis of xcvr, with negative going to alc jack of xcvr.   
>
>
>Jim   VE7RF