[BC] Transmitter failures

[Milton R Holladay Jr.]

In the late 80s, I saw a solid state 30kW UHF TV transmitter (Philips, IIRC)
at the NAB in LV, and, IIRC, it was not really terribly large, maybe
10'long.
Now, here we are, ~20 years later, and no one seems to be able to package a
VHF FM transmitter that is commensurately smaller; 100mHz should be a lot
easier and smaller to implement than 400+mHz . And then there is the
Platinum VHF TV line ; how big and powerful are they?
If progress moved linearly, it seems to me that we should have 20 or 30 kw
FMs the size of a couple of racks by now. Wha hoppen?
M
----- Original Message -----
From: "Mike McCarthy" <Towers at mre.com>
To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
Sent: Saturday, April 28, 2007 1:41 PM
Subject: Re: [BC] Transmitter failures


> Dave's point is the silver bullet of making tubes obsolete in TX's up to
> 30KW.  AM's now run 400 VDC for peak and about 150-175 for the RF PA's.
If
> we can double or tipple the power per device package at FM by using much
> higher voltages,  we should see AC/RF efficiencies jump to 75% or
> better.  Much like AM's.  Thus what is now a 10KW box will be a 15-20KW
> box...power supplies and combiner permitting.  A 20KW combined box of two
> TX's is now a 30KW (or more) box.
>
> MM
>
> At 12:59 PM 4/28/2007 -0400, DHultsman5 at aol.com wrote
> >