[Boatanchors] Using a SG-230 tuner on AM

[D C *Mac* Macdonald]

At 100% modulation peak, the instantaneous voltage
AND current are both double the static values.
 
V^2 times I^2 gives you four times the static power.
 
Current FCC rules allow for 1.5 kW output power.
That is why the old kilowatt rigs such as Collins
KW-1 and Johnson Desk Kilowatt can now only be run
at 375 Watts carrier power.
 
73 - Mac, K2GKK/5
Oklahoma City, OK



----------------------------------------
> From: km1h at jeremy.mv.com
> To: k2gkk at hotmail.com; boatanchors at mailman.qth.net
> Subject: Re: [Boatanchors] Using a SG-230 tuner on AM
> Date: Sun, 9 Aug 2009 15:55:55 -0400
>
> Its rated at 200W PEP.
>
> However I still have a hard time understanding how you get 4X PEP on AM.
>
> For 100% modulation it requires 50% of the RF plate input power. So thats
> 50W of audio on a 100W input final. At 70% efficiency thats 70W carrier and
> 50W of total audio using a rather conventional 1:1 modulation transformer
> ratio.
>
> For a Viking I at 100W out that is 140W input which requires 70W audio. That
> comes out at 170W PEP in my book.
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "D C *Mac* Macdonald" 
> To: "KM1H Carl Huether" ; 
> Sent: Sunday, August 09, 2009 3:26 PM
> Subject: RE: [Boatanchors] Using a SG-230 tuner on AM
>
>
>
> Carl and otherson the boatanchors list:
>
> I believe the SGC-230 is rated at 125 Watts PEP.
>
> Since the Viking, DX-100, 32V-*, B&W, etc. ran
> close to 120 Watts carrier, 100% modulation would
> cause PEP output to be 400-500 Watts.
>
> I don't believe it advisable to risk running that
> sort of power into the SGC.
>
> I'm pretty sure most list members are aware of that
> fact but I believe that it bears refreshing.
>
> 73 - Mac, K2GKK/5
> Oklahoma City, OK
>
>
> ----------------------------------------
>> From: km1h at jeremy.mv.com
>> To: boatanchors at mailman.qth.net
>> Date: Sun, 9 Aug 2009 14:30:11 -0400
>> Subject: [Boatanchors] Using a SG-230 tuner on AM
>>
>> Has anyone tried running a 100W output AM rig thru one of these?
>>
>> Id like to be able to be able to run a Viking I or II thru one using a 160
>> and 75M dipole in parallel for 160-20M.
>>
>> Carl
>> KM1H
>>=
>