Since the devices were designed for broadcast television applications,
I suspect they are designed for AB operation and the pulse rating is
a way of trying to prevent application designers from pushing them too
hard in pulse applications (MRI, RF heating, etc.). Both analog and
digital TV have a fairly high peak to average ratio.
I'm not up to speed on the most recent systems but the discussion on
early digital systems indicated a need for peak to average ratios in
the 6 to 7 dB range. That would mean somewhere around 275W average
(CW) for the 1200W PEP device in digital service. Analog wasn't quite
that bad but peak to average remained well above 3dB unless the scene
was very dark.
73,
... Joe, W4TV
On 8/21/2011 11:34 PM, Fuqua, Bill L wrote:
> I have not looked very close at the data sheet but it did occur to me that
> in some applications some devices require time to thermally or electrically
> stabalize.
> But, you may be right. I'll look closer.
> 73
> bill wa4lav
>
> ________________________________________
> From: amps-bounces@contesting.com [amps-bounces@contesting.com] On Behalf Of
> jeff millar [wa1hco@wa1hco.net]
> Sent: Sunday, August 21, 2011 9:24 PM
> To: amps@contesting.com
> Subject: Re: [Amps] MRFE6VP Datasheet
>
> I think the pulse operation applies to the 60:1 VSWR specification.
> Effectively, that gives a specification on how fast the control circuit need
> to
> operate.
>
> jeff, wa1hco
>
> On 08/21/2011 08:06 PM, Fuqua, Bill L wrote:
>> If it will do 1200W average power CW it should do the same in pulsed
>> mode.
>> The question is, why list both unless some application requires that
>> particular
>> pulse specification. It could be that the product was targeted for that
>> application.
>> And others (CW).
>> 73
>> Bill wa4lav
>
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